This article shows how to use the SSD1306 0.96 inch I2C OLED display with the Arduino. We’ll show you some features of the OLED display, how to connect it to the Arduino board, and how to write text, draw shapes and display bitmap images. Lastly, we’ll build a project example that displays temperature and humidity readings.
Introducing the 0.96 inch OLED display
The organic light-emitting diode (OLED) display that we’ll use in this tutorial is the SSD1306 model: a monocolor, 0.96-inch display with 128×64 pixels as shown in the following figure.
The OLED display doesn’t require backlight, which results in a very nice contrast in dark environments. Additionally, its pixels consume energy only when they are on, so the OLED display consumes less power when compared with other displays.
The model we’re using here has only four pins and communicates with the Arduino using I2C communication protocol. There are models that come with an extra RESET pin. There are also other OLED displays that communicate using SPI communication.
Pin wiring
Because the OLED display uses I2C communication protocol, wiring is very simple. You just need to connect to the Arduino Uno I2C pins as shown in the table below.
| Pin | Wiring to Arduino Uno |
| Vin | 5V |
| GND | GND |
| SCL | A5 |
| SDA | A4 |
If you’re using a different Arduino board, make sure you check the correct I2C pins:
- Nano: SDA (A4); SCL (A5);
- MEGA: SDA (20); SCL (21);
- Leonardo: SDA (20); SCL (21);
Libraries
To control the OLED display you need the adafruit_SSD1306.h and the adafruit_GFX.h libraries. Follow the next instructions to install those libraries.
1. Open your Arduino IDE and go to Sketch > Include Library > Manage Libraries. The Library Manager should open.
2. Type “SSD1306” in the search box and install the SSD1306 library from Adafruit.
3. After installing the SSD1306 library from Adafruit, type “GFX” in the search box and install the library.
4. After installing the libraries, restart your Arduino IDE.
Tips for writing text using these libraries
Here’s some functions that will help you handle the OLED display library to write text or draw simple graphics.
- display.clearDisplay() – all pixels are off
- display.drawPixel(x,y, color) – plot a pixel in the x,y coordinates
- display.setTextSize(n) – set the font size, supports sizes from 1 to 8
- display.setCursor(x,y) – set the coordinates to start writing text
- display.print(“message”) – print the characters at location x,y
- display.display() – call this method for the changes to make effect
Testing the OLED Display
After wiring the OLED display to the Arduino and installing all required libraries, you can use one example from the library to see if everything is working properly.
In your Arduino IDE, go to File > Examples > Adafruit SSD1306 and select the example for the display you’re using.
The following code should load:
/*********
Complete project details at https://randomnerdtutorials.com
This is an example for our Monochrome OLEDs based on SSD1306 drivers. Pick one up today in the adafruit shop! ------> http://www.adafruit.com/category/63_98
This example is for a 128x32 pixel display using I2C to communicate 3 pins are required to interface (two I2C and one reset).
Adafruit invests time and resources providing this open source code, please support Adafruit and open-source hardware by purchasing products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries, with contributions from the open source community. BSD license, check license.txt for more information All text above, and the splash screen below must be included in any redistribution.
*********/
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
#define NUMFLAKES 10 // Number of snowflakes in the animation example
#define LOGO_HEIGHT 16
#define LOGO_WIDTH 16
static const unsigned char PROGMEM logo_bmp[] =
{ B00000000, B11000000,
B00000001, B11000000,
B00000001, B11000000,
B00000011, B11100000,
B11110011, B11100000,
B11111110, B11111000,
B01111110, B11111111,
B00110011, B10011111,
B00011111, B11111100,
B00001101, B01110000,
B00011011, B10100000,
B00111111, B11100000,
B00111111, B11110000,
B01111100, B11110000,
B01110000, B01110000,
B00000000, B00110000 };
void setup() {
Serial.begin(115200);
// SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;); // Don't proceed, loop forever
}
// Show initial display buffer contents on the screen --
// the library initializes this with an Adafruit splash screen.
display.display();
delay(2000); // Pause for 2 seconds
// Clear the buffer
display.clearDisplay();
// Draw a single pixel in white
display.drawPixel(10, 10, WHITE);
// Show the display buffer on the screen. You MUST call display() after
// drawing commands to make them visible on screen!
display.display();
delay(2000);
// display.display() is NOT necessary after every single drawing command,
// unless that's what you want...rather, you can batch up a bunch of
// drawing operations and then update the screen all at once by calling
// display.display(). These examples demonstrate both approaches...
testdrawline(); // Draw many lines
testdrawrect(); // Draw rectangles (outlines)
testfillrect(); // Draw rectangles (filled)
testdrawcircle(); // Draw circles (outlines)
testfillcircle(); // Draw circles (filled)
testdrawroundrect(); // Draw rounded rectangles (outlines)
testfillroundrect(); // Draw rounded rectangles (filled)
testdrawtriangle(); // Draw triangles (outlines)
testfilltriangle(); // Draw triangles (filled)
testdrawchar(); // Draw characters of the default font
testdrawstyles(); // Draw 'stylized' characters
testscrolltext(); // Draw scrolling text
testdrawbitmap(); // Draw a small bitmap image
// Invert and restore display, pausing in-between
display.invertDisplay(true);
delay(1000);
display.invertDisplay(false);
delay(1000);
testanimate(logo_bmp, LOGO_WIDTH, LOGO_HEIGHT); // Animate bitmaps
}
void loop() {
}
void testdrawline() {
int16_t i;
display.clearDisplay(); // Clear display buffer
for(i=0; i<display.width(); i+=4) {
display.drawLine(0, 0, i, display.height()-1, WHITE);
display.display(); // Update screen with each newly-drawn line
delay(1);
}
for(i=0; i<display.height(); i+=4) {
display.drawLine(0, 0, display.width()-1, i, WHITE);
display.display();
delay(1);
}
delay(250);
display.clearDisplay();
for(i=0; i<display.width(); i+=4) {
display.drawLine(0, display.height()-1, i, 0, WHITE);
display.display();
delay(1);
}
for(i=display.height()-1; i>=0; i-=4) {
display.drawLine(0, display.height()-1, display.width()-1, i, WHITE);
display.display();
delay(1);
}
delay(250);
display.clearDisplay();
for(i=display.width()-1; i>=0; i-=4) {
display.drawLine(display.width()-1, display.height()-1, i, 0, WHITE);
display.display();
delay(1);
}
for(i=display.height()-1; i>=0; i-=4) {
display.drawLine(display.width()-1, display.height()-1, 0, i, WHITE);
display.display();
delay(1);
}
delay(250);
display.clearDisplay();
for(i=0; i<display.height(); i+=4) {
display.drawLine(display.width()-1, 0, 0, i, WHITE);
display.display();
delay(1);
}
for(i=0; i<display.width(); i+=4) {
display.drawLine(display.width()-1, 0, i, display.height()-1, WHITE);
display.display();
delay(1);
}
delay(2000); // Pause for 2 seconds
}
void testdrawrect(void) {
display.clearDisplay();
for(int16_t i=0; i<display.height()/2; i+=2) {
display.drawRect(i, i, display.width()-2*i, display.height()-2*i, WHITE);
display.display(); // Update screen with each newly-drawn rectangle
delay(1);
}
delay(2000);
}
void testfillrect(void) {
display.clearDisplay();
for(int16_t i=0; i<display.height()/2; i+=3) {
// The INVERSE color is used so rectangles alternate white/black
display.fillRect(i, i, display.width()-i*2, display.height()-i*2, INVERSE);
display.display(); // Update screen with each newly-drawn rectangle
delay(1);
}
delay(2000);
}
void testdrawcircle(void) {
display.clearDisplay();
for(int16_t i=0; i<max(display.width(),display.height())/2; i+=2) {
display.drawCircle(display.width()/2, display.height()/2, i, WHITE);
display.display();
delay(1);
}
delay(2000);
}
void testfillcircle(void) {
display.clearDisplay();
for(int16_t i=max(display.width(),display.height())/2; i>0; i-=3) {
// The INVERSE color is used so circles alternate white/black
display.fillCircle(display.width() / 2, display.height() / 2, i, INVERSE);
display.display(); // Update screen with each newly-drawn circle
delay(1);
}
delay(2000);
}
void testdrawroundrect(void) {
display.clearDisplay();
for(int16_t i=0; i<display.height()/2-2; i+=2) {
display.drawRoundRect(i, i, display.width()-2*i, display.height()-2*i,
display.height()/4, WHITE);
display.display();
delay(1);
}
delay(2000);
}
void testfillroundrect(void) {
display.clearDisplay();
for(int16_t i=0; i<display.height()/2-2; i+=2) {
// The INVERSE color is used so round-rects alternate white/black
display.fillRoundRect(i, i, display.width()-2*i, display.height()-2*i,
display.height()/4, INVERSE);
display.display();
delay(1);
}
delay(2000);
}
void testdrawtriangle(void) {
display.clearDisplay();
for(int16_t i=0; i<max(display.width(),display.height())/2; i+=5) {
display.drawTriangle(
display.width()/2 , display.height()/2-i,
display.width()/2-i, display.height()/2+i,
display.width()/2+i, display.height()/2+i, WHITE);
display.display();
delay(1);
}
delay(2000);
}
void testfilltriangle(void) {
display.clearDisplay();
for(int16_t i=max(display.width(),display.height())/2; i>0; i-=5) {
// The INVERSE color is used so triangles alternate white/black
display.fillTriangle(
display.width()/2 , display.height()/2-i,
display.width()/2-i, display.height()/2+i,
display.width()/2+i, display.height()/2+i, INVERSE);
display.display();
delay(1);
}
delay(2000);
}
void testdrawchar(void) {
display.clearDisplay();
display.setTextSize(1); // Normal 1:1 pixel scale
display.setTextColor(WHITE); // Draw white text
display.setCursor(0, 0); // Start at top-left corner
display.cp437(true); // Use full 256 char 'Code Page 437' font
// Not all the characters will fit on the display. This is normal.
// Library will draw what it can and the rest will be clipped.
for(int16_t i=0; i<256; i++) {
if(i == '\n') display.write(' ');
else display.write(i);
}
display.display();
delay(2000);
}
void testdrawstyles(void) {
display.clearDisplay();
display.setTextSize(1); // Normal 1:1 pixel scale
display.setTextColor(WHITE); // Draw white text
display.setCursor(0,0); // Start at top-left corner
display.println(F("Hello, world!"));
display.setTextColor(BLACK, WHITE); // Draw 'inverse' text
display.println(3.141592);
display.setTextSize(2); // Draw 2X-scale text
display.setTextColor(WHITE);
display.print(F("0x")); display.println(0xDEADBEEF, HEX);
display.display();
delay(2000);
}
void testscrolltext(void) {
display.clearDisplay();
display.setTextSize(2); // Draw 2X-scale text
display.setTextColor(WHITE);
display.setCursor(10, 0);
display.println(F("scroll"));
display.display(); // Show initial text
delay(100);
// Scroll in various directions, pausing in-between:
display.startscrollright(0x00, 0x0F);
delay(2000);
display.stopscroll();
delay(1000);
display.startscrollleft(0x00, 0x0F);
delay(2000);
display.stopscroll();
delay(1000);
display.startscrolldiagright(0x00, 0x07);
delay(2000);
display.startscrolldiagleft(0x00, 0x07);
delay(2000);
display.stopscroll();
delay(1000);
}
void testdrawbitmap(void) {
display.clearDisplay();
display.drawBitmap(
(display.width() - LOGO_WIDTH ) / 2,
(display.height() - LOGO_HEIGHT) / 2,
logo_bmp, LOGO_WIDTH, LOGO_HEIGHT, 1);
display.display();
delay(1000);
}
#define XPOS 0 // Indexes into the 'icons' array in function below
#define YPOS 1
#define DELTAY 2
void testanimate(const uint8_t *bitmap, uint8_t w, uint8_t h) {
int8_t f, icons[NUMFLAKES][3];
// Initialize 'snowflake' positions
for(f=0; f< NUMFLAKES; f++) {
icons[f][XPOS] = random(1 - LOGO_WIDTH, display.width());
icons[f][YPOS] = -LOGO_HEIGHT;
icons[f][DELTAY] = random(1, 6);
Serial.print(F("x: "));
Serial.print(icons[f][XPOS], DEC);
Serial.print(F(" y: "));
Serial.print(icons[f][YPOS], DEC);
Serial.print(F(" dy: "));
Serial.println(icons[f][DELTAY], DEC);
}
for(;;) { // Loop forever...
display.clearDisplay(); // Clear the display buffer
// Draw each snowflake:
for(f=0; f< NUMFLAKES; f++) {
display.drawBitmap(icons[f][XPOS], icons[f][YPOS], bitmap, w, h, WHITE);
}
display.display(); // Show the display buffer on the screen
delay(200); // Pause for 1/10 second
// Then update coordinates of each flake...
for(f=0; f< NUMFLAKES; f++) {
icons[f][YPOS] += icons[f][DELTAY];
// If snowflake is off the bottom of the screen...
if (icons[f][YPOS] >= display.height()) {
// Reinitialize to a random position, just off the top
icons[f][XPOS] = random(1 - LOGO_WIDTH, display.width());
icons[f][YPOS] = -LOGO_HEIGHT;
icons[f][DELTAY] = random(1, 6);
}
}
}
}
If your OLED doesn’t have a RESET pin, you should set the OLED_RESET variable to -1 as shown below:
#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Upload the code to your Arduino board. Don’t forget to select the right board and COM port in the Tools menu.
You should get a series of different animations in the OLED as shown in the following short video.
If your OLED display is not showing anything:
- Check that the OLED display is properly wired to the Arduino
- Double-check the OLED display I2C address: with the OLED connected to the Arduino, upload this code and check the I2C address in the Serial Monitor
You should change the OLED address in the following line, if necessary. In our case, the address is 0x3C.
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { Write Text – OLED Display
The Adafruit library for the OLED display comes with several functions to write text. In this section, you’ll learn how to write and scroll text using the library functions.
“Hello, world!” OLED Display
The following sketch displays Hello, world! message in the OLED display.
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
void setup() {
Serial.begin(115200);
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
delay(2000);
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0, 10);
// Display static text
display.println("Hello, world!");
display.display();
}
void loop() {
}
After uploading the code, this is what you’ll get in your OLED:
Let’s take a quick look on how the code works.
Importing libraries
First, you need to import the necessary libraries. The Wire library to use I2C and the Adafruit libraries to write to the display: Adafruit_GFX and Adafruit_SSD1306.
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>Initialize the OLED display
Then, you define your OLED width and height. In this example, we’re using a 128×64 OLED display. If you’re using other sizes, you can change that in the SCREEN_WIDTH, and SCREEN_HEIGHT variables.
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixelsThen, initialize a display object with the width and height defined earlier with I2C communication protocol (&Wire).
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);The (-1) parameter means that your OLED display doesn’t have a RESET pin. If your OLED display does have a RESET pin, it should be connected to a GPIO. In that case, you should pass the GPIO number as a parameter.
In the setup(), initialize the Serial Monitor at a baud raute of 115200 for debugging purposes.
Serial.begin(115200);Initialize the OLED display with the begin() method as follows:
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println("SSD1306 allocation failed");
for(;;); // Don't proceed, loop forever
}This snippet also prints a message on the Serial Monitor, in case we’re not able to connect to the display.
Serial.println("SSD1306 allocation failed");In case you’re using a different OLED display, you may need to change the OLED address. In our case, the address is 0x3C.
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { If this address doesn’t work, you can run an I2C scanner sketch to find your OLED address. You can find the I2C scanner sketch here.
After initializing the display, add a two second delay, so that the OLED has enough time to initialize before writing text:
delay(2000);Clear display, set font size, color and write text
After initializing the display, clear the display buffer with the clearDisplay() method:
display.clearDisplay();Before writing text, you need to set the text size, color and where the text will be displayed in the OLED.
Set the font size using the setTextSize() method:
display.setTextSize(1); Set the font color with the setTextColor() method:
display.setTextColor(WHITE); WHITE sets white font and black background.
Define the position where the text starts using the setCursor(x,y) method. In this case, we’re setting the text to start at the (0,10) coordinates.
display.setCursor(0,10); Finally, you can send the text to the display using the println() method, as follows:
display.println("Hello, world!");Then, you need to call the display() method to actually display the text on the screen.
display.display();Scrolling Text
The Adafruit OLED library provides useful methods to easily scroll text.
- startscrollright(0x00, 0x0F): scroll text from left to right
- startscrollleft(0x00, 0x0F): scroll text from right to left
- startscrolldiagright(0x00, 0x07): scroll text from left bottom corner to right upper corner
- startscrolldiagleft(0x00, 0x07): scroll text from right bottom corner to left upper corner
The following sketch implements those methods.
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
void setup() {
Serial.begin(115200);
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
delay(2000);
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0, 0);
// Display static text
display.println("Scrolling Hello");
display.display();
delay(100);
}
void loop() {
// Scroll in various directions, pausing in-between:
display.startscrollright(0x00, 0x0F);
delay(2000);
display.stopscroll();
delay(1000);
display.startscrollleft(0x00, 0x0F);
delay(2000);
display.stopscroll();
delay(1000);
display.startscrolldiagright(0x00, 0x07);
delay(2000);
display.startscrolldiagleft(0x00, 0x07);
delay(2000);
display.stopscroll();
delay(1000);
}
The text scrolls as shown in the following short video.
Using Other Fonts – OLED Display
The Adafruit GFX library allows us to use some alternate fonts besides the built-in fonts. It allows you to chose between Serif, Sans, and Mono. Each font is available in bold, italic and in different sizes.
The sizes are set by the actual font. So, the setTextSize() method doesn’t work with these fonts. The fonts are available in 9, 12, 18 and 24 point sizes and also contain 7-bit characters (ASCII codes) (described as 7b in the font name).
You can chose from the next selection of fonts:
FreeMono12pt7b.h FreeSansBoldOblique12pt7b.h
FreeMono18pt7b.h FreeSansBoldOblique18pt7b.h
FreeMono24pt7b.h FreeSansBoldOblique24pt7b.h
FreeMono9pt7b.h FreeSansBoldOblique9pt7b.h
FreeMonoBold12pt7b.h FreeSansOblique12pt7b.h
FreeMonoBold18pt7b.h FreeSansOblique18pt7b.h
FreeMonoBold24pt7b.h FreeSansOblique24pt7b.h
FreeMonoBold9pt7b.h FreeSansOblique9pt7b.h
FreeMonoBoldOblique12pt7b.h FreeSerif12pt7b.h
FreeMonoBoldOblique18pt7b.h FreeSerif18pt7b.h
FreeMonoBoldOblique24pt7b.h FreeSerif24pt7b.h
FreeMonoBoldOblique9pt7b.h FreeSerif9pt7b.h
FreeMonoOblique12pt7b.h FreeSerifBold12pt7b.h
FreeMonoOblique18pt7b.h FreeSerifBold18pt7b.h
FreeMonoOblique24pt7b.h FreeSerifBold24pt7b.h
FreeMonoOblique9pt7b.h FreeSerifBold9pt7b.h
FreeSans12pt7b.h FreeSerifBoldItalic12pt7b.h
FreeSans18pt7b.h FreeSerifBoldItalic18pt7b.h
FreeSans24pt7b.h FreeSerifBoldItalic24pt7b.h
FreeSans9pt7b.h FreeSerifBoldItalic9pt7b.h
FreeSansBold12pt7b.h FreeSerifItalic12pt7b.h
FreeSansBold18pt7b.h FreeSerifItalic18pt7b.h
FreeSansBold24pt7b.h FreeSerifItalic24pt7b.h
FreeSansBold9pt7b.h FreeSerifItalic9pt7b.hThe fonts that work better with the OLED display are the 9 and 12 points size.
To use one of those fonts, first you need to include it in your sketch, for example:
#include <Fonts/FreeSerif12pt7b.h>Next, you just need to use the setFont() method and pass as argument, the specified font:
display.setFont(&FreeSerif12pt7b);After specifying the font, all methods to write text will use that font. To get back to use the original font, you just need to call the setFont() method with no arguments:
display.setFont();Upload the next sketch to your board:
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Fonts/FreeSerif9pt7b.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
void setup() {
Serial.begin(115200);
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println("SSD1306 allocation failed");
for(;;);
}
delay(2000);
display.setFont(&FreeSerif9pt7b);
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0,20);
display.println("Hello, world!");
display.display();
delay(2000);
}
void loop() {
}
Now, your display prints the “Hello, world!” message in FreeSerif font.
Draw Shapes in the OLED Display
The Adafruit OLED library provides useful methods to draw pixels, lines and shapes. Let’s take a quick look at those methods.
Draw a pixel
To draw a pixel in the OLED display, you can use the drawPixel(x, y, color) method that accepts as arguments the x and y coordinates where the pixel appears, and color. For example:
display.drawPixel(64, 32, WHITE);Draw a line
Use the drawLine(x1, y1, x2, y2, color) method to create a line. The (x1, y1) coordinates indicate the start of the line, and the (x2, y2) coordinates indicates where the line ends. For example:
display.drawLine(0, 0, 127, 20, WHITE);Draw a rectangle
The drawRect(x, y, width, height, color) provides an easy way to draw a rectangle. The (x, y) coordinates indicate the top left corner of the rectangle. Then, you need to specify the width, height and color:
display.drawRect(10, 10, 50, 30, WHITE);You can use the fillRect(x, y, width, height, color) to draw a filled rectangle. This method accepts the same arguments as drawRect().
The library also provides methods to displays rectangles with round corners: drawRoundRect() and fillRoundRect(). These methods accepts the same arguments as previous methods plus the radius of the corner. For example:
display.drawRoundRect(10, 10, 30, 50, 2, WHITE);
Or a filled round rectangle:
display.fillRoundRect(10, 10, 30, 50, 2, WHITE);
Draw a circle
To draw a circle use the drawCircle(x, y, radius, color) method. The (x,y) coordinates indicate the center of the circle. You should also pass the radius as an argument. For example:
display.drawCircle(64, 32, 10, WHITE);In the same way, to build a filled circle, use the fillCircle() method with the same arguments:
display.fillCircle(64, 32, 10, WHITE);
Draw a triangle
Use the the drawTriangle(x1, y1, x2, y2, x3, y3, color) method to build a triangle. This method accepts as arguments the coordinates of each corner and the color.
display.drawTriangle(10, 10, 55, 20, 5, 40, WHITE);Use the fillTriangle() method to draw a filled triangle.
display.fillTriangle(10, 10, 55, 20, 5, 40, WHITE);
Invert
The library provides an additional method that you can use with shapes or text: the invertDisplay() method. Pass true as argument to invert the colors of the screen or false to get back to the original colors.
If you call the following command after defining the triangle:
display.invertDisplay(true);You’ll get an inverted triangle as follows:
Code – Draw Shapes
Upload the following sketch that implements each snippet of code we’ve covered previously and goes through all the shapes.
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
void setup() {
Serial.begin(115200);
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
delay(2000); // Pause for 2 seconds
// Clear the buffer
display.clearDisplay();
// Draw a single pixel in white
display.drawPixel(64, 32, WHITE);
display.display();
delay(3000);
// Draw line
display.clearDisplay();
display.drawLine(0, 0, 127, 20, WHITE);
display.display();
delay(3000);
// Draw rectangle
display.clearDisplay();
display.drawRect(30, 10, 50, 30, WHITE);
display.display();
delay(3000);
// Fill rectangle
display.fillRect(30, 10, 50, 30, WHITE);
display.display();
delay(3000);
// Draw round rectangle
display.clearDisplay();
display.drawRoundRect(10, 10, 30, 50, 2, WHITE);
display.display();
delay(3000);
// Fill round rectangle
display.clearDisplay();
display.fillRoundRect(10, 10, 30, 50, 2, WHITE);
display.display();
delay(3000);
// Draw circle
display.clearDisplay();
display.drawCircle(64, 32, 10, WHITE);
display.display();
delay(3000);
// Fill circle
display.fillCircle(64, 32, 10, WHITE);
display.display();
delay(3000);
// Draw triangle
display.clearDisplay();
display.drawTriangle(10, 10, 55, 20, 5, 40, WHITE);
display.display();
delay(3000);
// Fill triangle
display.fillTriangle(10, 10, 55, 20, 5, 40, WHITE);
display.display();
delay(3000);
// Invert and restore display, pausing in-between
display.invertDisplay(true);
delay(3000);
display.invertDisplay(false);
delay(3000);
}
void loop() {
}
Display Bitmap Images in the OLED
You can display 128×64 bitmap monocolor images on the OLED display.
First, use an imaging program to resize a photo or picture and save it as monochrome bitmap. If you’re on a Windows PC, you can use Paint.
Then, use a Image to C Array converter to convert the image into an array. I’ve used LCD Image Converter.
Run the program and start with a new image. Go to Image > Import and select the bitmap image you’ve created earlier.
Go to Options > Conversion and in the Prepare tab, select the following options:
- Type: Monochrome, Threshold Dither
- Main Scan Direction: Top to Bottom
- Line Scan Direction: Forward
Go to the Image tab and select the following options:
- Split to rows
- Block size: 8 bit
- Byte order: Little-Endian
Then, click OK. Finally, in the main menu, go to File > Convert. A new file with .c extension should be saved. That file contains the C array for the image. Open that file with a text editor, and copy the array.
In our case, this is the array that we get:
static const uint8_t image_data_Saraarray[1024] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x00, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x14, 0x9e, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x36, 0x3f, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x6d, 0xff, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0xfb, 0xff, 0x80, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x03, 0xd7, 0xff, 0x80, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x07, 0xef, 0xff, 0x80, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x0f, 0xdf, 0xff, 0x90, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x0f, 0xbf, 0xff, 0xd0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x1d, 0x7f, 0xff, 0xd0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x01, 0x1b, 0xff, 0xff, 0xc0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x02, 0xa7, 0xff, 0xff, 0xc0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x03, 0xff, 0xc0, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00, 0xff, 0x80, 0x00, 0x0b, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0x03, 0xff, 0xff, 0xff, 0xf0, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x07, 0xff, 0xff, 0xff, 0xf0, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x0f, 0x07, 0xff, 0xf8, 0xf8, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x0e, 0x01, 0xff, 0xc0, 0x38, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x1c, 0x46, 0xff, 0xb1, 0x18, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x3f, 0x97, 0xff, 0xc0, 0x7a, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xfe, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xfe, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x01, 0x3f, 0xff, 0xff, 0xff, 0xfe, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x01, 0xbf, 0xff, 0xff, 0xff, 0xfe, 0x81, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0xbf, 0xff, 0xff, 0xff, 0xfc, 0x81, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0xff, 0xff, 0xfe, 0xff, 0xfd, 0x83, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0xbf, 0xff, 0xfe, 0xff, 0xfd, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x7f, 0xff, 0xff, 0xff, 0xff, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x7f, 0xff, 0xff, 0xff, 0xfb, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x3f, 0xff, 0xdc, 0xff, 0xfa, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xd8, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xf8, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xd0, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xf8, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x90, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xf8, 0x02, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xb0, 0x00, 0x0f, 0xf5, 0xff, 0xd7, 0xf8, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xb0, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x5f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xa0, 0x00, 0x0f, 0xfb, 0xff, 0xff, 0xf0, 0x00, 0x3f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x0f, 0xfd, 0xff, 0xdf, 0xf0, 0x00, 0x3f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x07, 0xff, 0xff, 0xbf, 0xf0, 0x00, 0x0f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x07, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x87, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x03, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x43, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x60, 0x00, 0x01, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x73, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfe, 0xe0, 0x00, 0x00, 0xff, 0xff, 0xff, 0x80, 0x00, 0x7b, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfd, 0xe0, 0x00, 0x00, 0x7f, 0xff, 0xfe, 0x00, 0x00, 0x33, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfd, 0xe0, 0x00, 0x00, 0x3f, 0xff, 0xf8, 0x00, 0x00, 0x27, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00, 0x0f, 0xff, 0xf0, 0x00, 0x00, 0x0f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x60, 0x00, 0x00, 0x67, 0xff, 0xe0, 0x00, 0x00, 0x1b, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfd, 0x40, 0x00, 0x00, 0xf3, 0xff, 0xc4, 0x00, 0x00, 0x0b, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfe, 0x80, 0x00, 0x00, 0xfc, 0xff, 0x8c, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x7f, 0x3c, 0x3c, 0x00, 0x00, 0x07, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x3f, 0xc0, 0x7c, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xfc, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff
};
Copy your array to the sketch. Then, to display the array, use the drawBitmap() method that accepts the following arguments (x, y, image array, image width, image height, rotation). The (x, y) coordinates define where the image starts to be displayed.
Copy the code below to display your bitmap image in the OLED.
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
static const unsigned char PROGMEM image_data_Saraarray[] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x00, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x14, 0x9e, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x36, 0x3f, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x6d, 0xff, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x00, 0xfb, 0xff, 0x80, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0x03, 0xd7, 0xff, 0x80, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x07, 0xef, 0xff, 0x80, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x0f, 0xdf, 0xff, 0x90, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x0f, 0xbf, 0xff, 0xd0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x1d, 0x7f, 0xff, 0xd0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x01, 0x1b, 0xff, 0xff, 0xc0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xf0, 0x02, 0xa7, 0xff, 0xff, 0xc0, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x03, 0xff, 0xc0, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00, 0xff, 0x80, 0x00, 0x0b, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0x03, 0xff, 0xff, 0xff, 0xf0, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x07, 0xff, 0xff, 0xff, 0xf0, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x0f, 0x07, 0xff, 0xf8, 0xf8, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x0e, 0x01, 0xff, 0xc0, 0x38, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x1c, 0x46, 0xff, 0xb1, 0x18, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x3f, 0x97, 0xff, 0xc0, 0x7a, 0x07, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xfe, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xfe, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x01, 0x3f, 0xff, 0xff, 0xff, 0xfe, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfe, 0x01, 0xbf, 0xff, 0xff, 0xff, 0xfe, 0x81, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0xbf, 0xff, 0xff, 0xff, 0xfc, 0x81, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x00, 0xff, 0xff, 0xfe, 0xff, 0xfd, 0x83, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0xbf, 0xff, 0xfe, 0xff, 0xfd, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x7f, 0xff, 0xff, 0xff, 0xff, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x7f, 0xff, 0xff, 0xff, 0xfb, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x3f, 0xff, 0xdc, 0xff, 0xfa, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xd8, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xf8, 0x03, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xd0, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xf8, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x90, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xf8, 0x02, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xb0, 0x00, 0x0f, 0xf5, 0xff, 0xd7, 0xf8, 0x01, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xb0, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x5f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xa0, 0x00, 0x0f, 0xfb, 0xff, 0xff, 0xf0, 0x00, 0x3f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x0f, 0xfd, 0xff, 0xdf, 0xf0, 0x00, 0x3f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x07, 0xff, 0xff, 0xbf, 0xf0, 0x00, 0x0f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x07, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x87, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x03, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x43, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x60, 0x00, 0x01, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x73, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfe, 0xe0, 0x00, 0x00, 0xff, 0xff, 0xff, 0x80, 0x00, 0x7b, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfd, 0xe0, 0x00, 0x00, 0x7f, 0xff, 0xfe, 0x00, 0x00, 0x33, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfd, 0xe0, 0x00, 0x00, 0x3f, 0xff, 0xf8, 0x00, 0x00, 0x27, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00, 0x0f, 0xff, 0xf0, 0x00, 0x00, 0x0f, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x60, 0x00, 0x00, 0x67, 0xff, 0xe0, 0x00, 0x00, 0x1b, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfd, 0x40, 0x00, 0x00, 0xf3, 0xff, 0xc4, 0x00, 0x00, 0x0b, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfe, 0x80, 0x00, 0x00, 0xfc, 0xff, 0x8c, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x7f, 0x3c, 0x3c, 0x00, 0x00, 0x07, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x3f, 0xc0, 0x7c, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xfc, 0x00, 0x00, 0x03, 0xff, 0xff, 0xff
};
void setup() {
Serial.begin(115200);
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
delay(2000); // Pause for 2 seconds
// Clear the buffer.
display.clearDisplay();
// Draw bitmap on the screen
display.drawBitmap(0, 0, image_data_Saraarray, 128, 64, 1);
display.display();
}
void loop() {
}
After uploading the code, this is what we get on the display.
Display Temperature and Humidity in the OLED Display with Arduino
In this section we’ll build a project that displays temperature and humidity readings on the OLED display. We’ll get temperature and humidity using the DHT11 temperature and humidity sensor. If you’re not familiar with the DHT11 sensor, read the following article:
Parts required
To complete this project you need the following components:
- 0.96 inch OLED display
- Arduino – Read Best Arduino Starter Kits
- DHT11 or DHT22 temperature and humidity sensor
- Breadboard
- 4.7k Ohm resistor (or 10k Ohm resistor)
- Jumper wires
You can use the preceding links or go directly to MakerAdvisor.com/tools to find all the parts for your projects at the best price!
Schematic
Assemble the circuit by following the next schematic diagram.
Note: if you’re using a module with a DHT sensor, it normally comes with only three pins. The pins should be labeled so that you know how to wire them. Additionally, many of these modules already come with an internal pull up resistor, so you don’t need to add one to the circuit.
Installing Libraries
Before proceeding, make sure you have installed the“adafruit_GFX.h” and the “adafruit_SSD1306.h” libraries to control the OLED display.
For this project you also need two aditional libraries to read from the DHT sensor: the DHT library and the Adafruit_Sensor library. Follow the next steps to install those libraries
1. Open your Arduino IDE and go to Sketch > Include Library > Manage Libraries. The Library Manager should open.
2. Search for “DHT” on the Search box and install the DHT library from Adafruit.
3. After installing the DHT library from Adafruit, type “Adafruit Unified Sensor” in the search box. Scroll all the way down to find the library and install it.
4. Restart your Arduino IDE.
Code
After installing all the necessary libraries, you can upload the following code.
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
#define DHTPIN 2 // Digital pin connected to the DHT sensor
// Uncomment the type of sensor in use:
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22 (AM2302)
//#define DHTTYPE DHT21 // DHT 21 (AM2301)
DHT dht(DHTPIN, DHTTYPE);
void setup() {
Serial.begin(115200);
dht.begin();
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
delay(2000);
display.clearDisplay();
display.setTextColor(WHITE);
}
void loop() {
delay(5000);
//read temperature and humidity
float t = dht.readTemperature();
float h = dht.readHumidity();
if (isnan(h) || isnan(t)) {
Serial.println("Failed to read from DHT sensor!");
}
//clear display
display.clearDisplay();
// display temperature
display.setTextSize(1);
display.setCursor(0,0);
display.print("Temperature: ");
display.setTextSize(2);
display.setCursor(0,10);
display.print(t);
display.print(" ");
display.setTextSize(1);
display.cp437(true);
display.write(167);
display.setTextSize(2);
display.print("C");
// display humidity
display.setTextSize(1);
display.setCursor(0, 35);
display.print("Humidity: ");
display.setTextSize(2);
display.setCursor(0, 45);
display.print(h);
display.print(" %");
display.display();
}
How the Code Works
Read this section if you want to learn how the code works. Otherwise, you can skip to the “Demonstration” section.
Importing libraries
The code starts by including the necessary libraries. The Wire, Adafruit_GFX and Adafruit_SSD1306 are used to interface with the OLED display. The Adafruit_Sensor and the DHT libraries are used to interface with the DHT22 or DHT11 sensors.
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>Create a display object
Then, define your OLED display dimensions. In this case, we’re using a 128×64 pixel display.
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixelsThen, initialize a display object with the width and height defined earlier with I2C communication protocol (&Wire).
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);The (-1) parameter means that your OLED display doesn’t have a RESET pin. If your OLED display does have a RESET pin, it should be connected to a GPIO. In that case, you should pass the GPIO number as a parameter.
Create a DHT object
Then, define the DHT sensor type you’re using. If you’re using a DHT11 you don’t need to change anything on the code. If you’re using another sensor, just uncomment the sensor you’re using and comment the others.
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22 (AM2302)
//#define DHTTYPE DHT21 // DHT 21 (AM2301)Initialize a DHT sensor object with the pin and type defined earlier.
DHT dht(DHTPIN, DHTTYPE);setup()
In the setup(), initialize the serial monitor for debugging purposes.
Serial.begin(115200);Initialize the DHT sensor:
dht.begin();Then, initialize the OLED display.
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}In this case, the address of the OLED display we’re using is 0x3C. If this address doesn’t work, you can run an I2C scanner sketch to find your OLED address. You can find the I2C scanner sketch here.
Add a delay to give time for the display to initialize, clear the display and set the text color to white:
delay(2000);
display.clearDisplay();
display.setTextColor(WHITE)In the loop() is where we read the sensor and display the temperature and humidity on the display.
Get temperature and humidity readings from DHT
The temperature and humidity are saved on the t and h variables, respectively. Reading temperature and humidity is as simple as using the readTemperature() and readHumidity() methods on the dht object.
float t = dht.readTemperature();
float h = dht.readHumidity();In case we are not able to get the readings, display an error message:
if (isnan(h) || isnan(t)) {
Serial.println("Failed to read from DHT sensor!");
}If you get that error message, read our troubleshooting guide: how to fix “Failed to read from DHT sensor”.
Display sensor readings on the OLED display
The following lines display the temperature on the OLED display.
display.setTextSize(1);
display.setCursor(0,0);
display.print("Temperature: ");
display.setTextSize(2);
display.setCursor(0,10);
display.print(t);
display.print(" ");
display.setTextSize(1);
display.cp437(true);
display.write(167);
display.setTextSize(2);
display.print("C");We use the setTextSize() method to define the font size, the setCursor() sets where the text should start being displayed and the print() method is used to write something on the display.
To print the temperature and humidity you just need to pass their variables to the print() method as follows:
display.print(t);The “Temperature” label is displayed in size 1, and the actual reading is displayed in size 2.
To display the º symbol, we use the Code Page 437 font. For that, you need to set the cp437 to true as follows:
display.cp437(true);Then, use the write() method to display your chosen character. The º symbol corresponds to character 167.
display.write(167);A similar approach is used to display the humidity:
display.setTextSize(1);
display.setCursor(0, 35);
display.print("Humidity: ");
display.setTextSize(2);
display.setCursor(0, 45);
display.print(h);
display.print(" %"); Don’t forget that you need to call display.display() at the end, so that you can actually display something on the OLED.
display.display(); Demonstration
After wiring the circuit and uploading the code, the OLED display shows the temperature and humidity readings. The sensor readings are updated every five seconds.
Troubleshooting
If your DHT sensor fails to get the readings or you get the message “Failed to read from DHT sensor”, read our DHT Troubleshooting Guide to help you solve that problem.
If you get the “SSD1306 allocation failed” error or if the OLED is not displaying anything in the screen, it can be one of the following issues:
Wrong I2C address
The I2C address for the OLED display we are using is 0x3C. However, yours may be different. So, make sure you check your display I2C address using an I2C scanner sketch.
SDA and SCL not connected properly
Please make sure that you have the SDA and SCL pins of the OLED display wired correctly.
Wrapping Up
The OLED display provides an easy and inexpensive way to display text or graphics using an Arduino. We hope you’ve found this guide and the project example useful.
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Thanks for reading
Thanks for the guide.
No problem! Thanks for reading Steve
Awesome Rui, I’ve been looking at these displays with much interest. This looks like fun! 🙂
They work great, but keep in mind that they are very very small. Thanks!
muchas gracias por la contribucion. felicitaciones por su labor. siga adelante 🙂
You’re welcome Cesar!
Very interesting! I appreciate your effort Mr. Rui.
Thanks Shehu!
It is too advanced for me right now, I keep it for when the time is right. It seems very simply explained, Congratulations
Thanks for reading, if you follow each step at a time, you’ll see it’s very easy.
Rui
Rui
I could use a little guidance with MULTIPLE OLED displays :-).. I have two OLEDs (.96″ I2C) but with different addresses (03c and 03d). I need to print to one with some fixed data (ie a string) and the other with variable data (ie read.analog(0)..) to make one “large” display. Can’t figure out the arduino code to do this beyond the “display.begin(SSD1306_SWITCHCAPVCC, 0x3D); ” statement. Any ideas suggestions would be greatly appreciated Thanks
TOM
Hi Tom,
I’ve never tried that, so I can’t give you a clear explanation of how to make it work without trying myself.
Thanks and good luck with your project,
Rui
This is a good guide to get you going. To use two displays, you can create two different “display” instances, e.g. displayFixed and displayVariable at the discovered addresses then handle writing the data in code. Another approach would be to create a C++ class that automatically does the Wire scan in the constructor to get the device addresses dynamically and has methods that handle writing to each I2C OLED.
it looks like we have the same module, and if i understand it correctly there is a very small spot on the back, where you can solder two small spots to enable a different address. on mine, one is already soldered with a tiny resistor for address 3D, i assume we can just desolder the one side and add a small glob to the other. doesnt look like we can use more than two, though. oh crap i just realised i’m like 7 years too late hah
You have to mesure the resistance of the resistor first. in my case it was a 4k7 resistor. if I didn’t sloder a resistor between the contacts it could burn the oled. Been there, done that, never again.
Hi,
(I don’t think it’s a resistor, but a capacitor.)
I desoldered it (left and middle contacts) and soldered it to middle and right.
So only 2 addresses are possible.
Sounds too advanced for my short, fat fingers to handle. At least I know it can be done. Maybe when I get more comfortable at soldering……
Thanks guys.
Doesn’t matter if you were late for the OP, other people may come here years later and get very useful information, like me, I would never think of looking under the PCB, so thanks a lot for your comment !
Very, very interesting !!!!!!!!!
Thanks for your feedback Menel!
Regards,
Rui
This is a great tutorial. You’ve made the OLED display simple even for me. The examples in the library are too advanced to grasp.
Hi. We’re glad you’ve enjoyed.
Thanks.
Thank you for sharing your time and knowledge with us. I have enjoyed the tutorials and I have learned quite a bit.
Cheers,
Steve
I’d been searching for nearly 3 months that how to properly display the content I want on a OLED screen; came across this site, really helped me in my project. Thanks!
Hi.
I’m glad you’ve found our content useful.
Good luck with your projects.
Regards,
Sara 🙂
Thanks for the guide. you are the best!!!!
You’re welcome 🙂
After some sketch issues…I was able to get this working with the OLED .96 display… It works great and I find the display is adequate enough…
Thanks for the projects!!!
Great! 🙂
Hi Rui, I finally got my hands on some of these displays. The first one was failed on arrival. the second one worked for 2 days and failed, I now have a third one received today and it works but IDK for how long. I’m wondering if others are having a high failure rate with these. I bought mine from several different ebay vendors. The first one never illuminated, but I could see data and clock on the SDA & SCL lines. The second one worked on both 3.3v and 5v as the listing stated, but failed. The one I have now I plan to run from a pro mini 3.3v version just to see if it lasts longer. But all 3 vendors stated in their listings that they should run on either 3.3 or 5 volts. Any thoughts?
Excuse me, where can i get the libraries for the OLED display??
Hi.
You can find the libraries in the following links:
– https://github.com/adafruit/Adafruit_SSD1306
– https://github.com/adafruit/Adafruit-GFX-Library
I’m new to all this. When I put in the code I get an error message. fatal error: vector: No such file or directory. I downloaded the libraries. Thanks for your time!
Hi Kg.
You also need to install the adafruit sensor library: https://github.com/adafruit/Adafruit_Sensor
If you’re using web editor take a look at this topic: forum.arduino.cc/index.php?topic=574940.msg3915277#msg3915277
Regards,
Sara
Thanks for the free Downloads.I want to Donate you but the link i found doesnt work.
Please send me your Adresse that I can Donate you with PayPal.
You now lot from this Electronic and programming Stuff.Yor little Sister i like
to see so much as well.
Nice Regards from Germany
Hi Dieter.
The link should be working fine: https://www.paypal.me/RuiFSantos
The best way to support our work is by getting one of our courses. Besides supporting our work, you also get access to our exclusive resources to learn more.
You can find our courses here: https://randomnerdtutorials.com/courses/
Thank you so much for supporting our work and I’m glad that you like our content.
Regards,
Sara
M. Rui,
I learn lots and want to learn more . how i will create a Number writing by LED or square? need more books. all the time on online, its make problem of my eyes. soooooooooo, what you kind suggestion
Hi.
I’m sorry, but I didn’t understand your question.
Regards,
Sara
Nicely explained..Easy to understand..
Thanks
Thanks for reading! I’m glad you found it helpful.
i need help with displaying a bitmap image it keeps saying expected primary expression before display refering to
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
and i dont know why. help would be appreciated.
Hi.
Can you copy the exact error you’re getting?
your web infor. help me a lot , I can do many topics on OLED eg. scrolling text,Hello world ,draw shape, Display DHT T ,RH But for display bitmap ,I Can’t get the picture on screen .
I think I have done something wrong on conversion process . the reason is
when I copy saraarray to sketch ,I can get the picture on OLED screen .
How to convert picture to 128×64 with 1024 pixels ?
Hi.
If you’re using windows, you can open your image in Paint. It has a resize option where you can resize your image. You can also crop your image so that your have the same dimensions. You can also try an online image resizer.
You also need to save your picture as monochrome bitmap format.
Regards,
Sara
Hi
thank you for your immediate response .
I think may be I do mistakes in photo file to C array conversion and did error in programming .
I use paint program to resize file to 128×64 and convert to C array ,copy code to sketch upload file and get unexpected display on half part of screen , 4 column of small line .
in program part ,
your program “static const unsigned char PROGMEM image_data_Saraarray[1024] = { ” .
My program “static const uint8_t image_data_ta_eu_1c[400] = {” but I had mark ” // “to cancel this .
Can I have your email address to send conversion file ?
please help me
chat
Hi.
To have your image displayed properly, it should be an array with 1024 size. Yours have 400.
You are probably doing something wrong in the conversion to C array. Are you using the same program as described in the tutorial? sourceforge.net/projects/lcd-image-converter/files/
Regards,
Sara
Hi
I use same program to convert
in my last conversion I can have 1024 size but the c array look strange
0xffempty , 0xffempty ,0xffempty ,……
I don’t know why .
thanks
chat
Hi
I use same program to convert
in my last conversion I can have 1024 size but the c array look strange
0xffempty , 0xffempty ,0xffempty ,……
I don’t know why .
thanks
chat
I’m sorry, but I don’t know what can be wrong.
Hi, can I use different colors to display the text like “BLUE” or “RED”?
Hi.
This OLED display is monochrome.
But there are other models that can display colors.
Regards,
Sara
Rui e Sara,
Excellent tutorial. Complete and functional!
Thank you very much.
“Excelente tutorial. Completo e funcional!
Muito obrigado.”
Gustavo Murta
Thanks for reading!
Caro Rui Santos,
Baseando-me no seu excelente tutorial sobre OLED , desenvolvi um outro tutorial:
Sensor de nível de caixa d’água (Arduino) – sem fio !
https://blog.eletrogate.com/sensor-de-nivel-de-caixa-dagua-sem-fio/
Muito obrigado pelo compartilhamento do seu conhecimento!
Abraços além mar,
Gustavo Murta (Brasil)
Thanks, Rui & Sara! Your examples *always* work for me. 🙂
The equivalent examples at Adafruit are using their OLED, which is addressed differently than just about everything you’d get from eBay or Ali, and they never once mention changing the I2C address. You not only warn about different addresses, you give us the I2C_scanner tool to figure out which one we’ve bought. The address on mine didn’t match what’s printed on the bottom silkscreen (nor the Adafruit default), so I’d have been running in circles with a blank display. VERY well thought-out demonstrations.
(chuckling) Spell check messed you up: two different places above it says ‘monologue’ where you meant ‘monochrome’. 😉
Hi Harry.
Thank you for your nice words.
Were you able to get your display working?
Thanks for telling me about the “monologue”. I haven’t noticed it, but it is fixed now.
Regards,
Sara
Congratulations guys, great tutorial !!
One question: can you use other pins than those set (A4 and A5) for i2c bus communication?
Hi Frausto.
Yes. There are some libraries that do that.
For example: https://github.com/todbot/SoftI2CMaster
Regards,
Sara
thank you!!!
that is very useful
thanks a lot
can we scroll text vertically ?
Yes.
You can do that. But we don’t have the function to do it.
Hmm can it become colorful?
Can it show a painting with colors?
Hi.
This OLED display model only displays black and white.
There are other models that can display colors, but not this one.
Regards,
Sara
Great tutorial! Thank you for this.
Is it possible to display the Temperature in Fahrenheit?
Thanks again,
Ron
Yes.
To read temperature in Fahrenheit use:
float f = dht.readTemperature(true);
Regards,
Sara
Thank you Sara! Much appreciated!
Ron
Hi Sara,
I have one more question and my apologies for asking multiple questions.
I have one of the oled that are yellow and blue. Basically the temperature is displaying half yellow and half blue. I know this is how these particular models are made, but is there any code I can use that would possibly shift the letters lower on the screen or eliminate the yellow color in a sketch?
Thanks again,
Ron
Hi Ron.
You can place the letter lower on the screen if you choose a different place to place the cursor to start writing the text. Increase the y coordinate.
display.setCursor(x,y)
Regards,
Sara
Excellent tutorial–thank you. A small thing: in the picture showing the temperature and humidity, I think that what is shown is not the degree sign (°), but something called “masculine ordinal indicator” (ASCII 167). The degree sign is ASCII 248. (In some fonts they look the same.)
Hi.
Yes, I think you’re right.
Thanks for sharing that. We’ll update the tutorial.
Regards,
Sara
Thanks for a nice tutorial on OLED, but a significant section is missing! How do I replace the 0.96 inch OLED display with a different size and controller? There are a great deal of sketches that are only written for the 0.96 inch OLED display, but how can I replace this display with e.g. and 1.5 inch 128×128 SSD 1327 display?
* Is it necessary to write a new sketch?
* If the same sketch can be used, where should it be corrected and with what values?
* You can use the “Display Temperature and Humidity in the OLED Display with Arduino” sketch as an example!
With best regards
Georg Berthelsen
Really amazing! I am 12 years old and I am able to do this as you explain it so well!
That’s great! 😀
Great!.
The OLED Display module include pull up resistors for i2c communication?
I’ll use a RTC DS3231 and OLED Display on the ESP32 in the same port i2c.
Hi Rodrigo.
They include the pull-up resistors for I2C.
You can connect them directly to the ESP32 I2C port. And yes, you can use the same port.
Learn more about I2C with the ESP32: https://randomnerdtutorials.com/esp32-i2c-communication-arduino-ide/
Regards,
Sara
Great tutorial. Very clear and helpful. Step by step. Thanks for the effort and all the info 🙂
Thank you 🙂
Very nice tutorial……………………!
Thanks!
That was a brilliant guide. Thank you so much 🙂
Hi again i have been looking around but am unable to find an example of how to scroll long text (longer than the display) i assume that must be difficult since no one has any examples of it. Can you point me anywhere ?
Hi.
We’ve created some scrolling functions, but for MicroPython.
Maybe you want to take a look at the tutorial and try to “translate” the functions to C.
https://randomnerdtutorials.com/micropython-ssd1306-oled-scroll-shapes-esp32-esp8266/
Regards,
Sara
Hi thanks for answering I found the solution it involves moving the cursor position to a negative number and printing the string in a loop.
I have a problem with the program line:
Adafruit_SSD1306 display (SCREEN_WIDTH, SCREEN_HEIGHT, & Wire, -1); . The compiler writes: ʻAdafruit_SSD1306` does not name a type; … I can’t find any errors. I ask for help! thank you and
Greetings from Horst.
Hi.
Did you copy the entiry code?
Make sure that you’ve copied the lines to include the library.
You can copy the code from here: https://raw.githubusercontent.com/RuiSantosdotme/Random-Nerd-Tutorials/master/Projects/OLED/oled_hello_world.ino
Regards,
Sara
My display is filled with black dots on a white background. ): I followed the tutorial and no matter which sketch I load it stays the same. Help please my display is new. ):. I’m using an original Arduino nano and a SSD1306 128×64 display.
Good day. I’m having the same problem your reported. I can tell that the display is correct but only showing in the top 3 mm of the display. the bottom 80% is white with black dots. I’m wondering if you found a solution? If so, help me please.
I have a problem with the display that I don’t know if it can help me. After a few seconds of uploading the code to the NANO, the image freezes or all the code restarts very very often.
After reading forums for several hours, I realized that the problem is not the code but the Wire.h library, which causes the reading to hang through the I2c port. Apparently the solution is to use SBWire.h, but so far I have not been able to get it to work. Do you know anything about this problem?
Hello,
This tutorial was great, thank you! I am coming across one issue where I am getting unexpected display when I use PROGMEM… if I do not include it everything is displayed properly but I run low on memory and when I do use it, the graphics are not at all displayed correctly. Would you happen to have any insight about this?
The difference is between
static const unsigned char frame1_bits[] = { …}; and
static const unsigned char frame1_bits[] PROGMEM = { .. };
and I am sending it:
u8g2.clearBuffer();
u8g2.drawXBM( 0, 0, frame1_width, frame1_height, frame1_bits );
u8g2.sendBuffer();
delay( 500 );
Thank you for taking your time to read and help out 🙂
I try to learn more about I2C and bought an Oled. To handle an Oled without documentation and all its addresses is a next step after sensors. Thanks to this article the display is working and the used code gives a next step to investigate.
Hello,
my display runs, nevertheless I read in this article with great interest,
thank you for this great work!
My ‘new’ problem: I want to drive 2 displays (addresses 60 and 61).
In July 29, 2018 at 11:47 am JayAchTee wrote
… To use two displays, you can create two different “display” instances, e.g. displayFixed and displayVariable at the discovered addresses …
I tried
#include <Wire.h>
#include <Adafruit_SSD1306.h>
Adafruit_SSD1306 oled(128, 64, &Wire, -1);
Adafruit_SSD1306 oled_2(128, 64, &Wire, -1);
…
void setup() {
if(!oled.begin(SSD1306_SWITCHCAPVCC, 61)) {
Serial.println(“SSD1306 allocation failed”);
for(;;); // Don’t proceed, loop forever
}
// adafruit “logo” is shown on device 61
if(!oled_2.begin(SSD1306_SWITCHCAPVCC, 60)) {
Serial.println(“SSD1306 allocation2 failed”);
for(;;); // Don’t proceed, loop forever
}
// program stops here
No success with oled_2
Who knows how to fit ?
Thanks in advance!
you gotta remove:
if(!oled.begin(SSD1306_SWITCHCAPVCC, 61)) {
Serial.println(“SSD1306 allocation failed”);
for(;;); // Don’t proceed, loop forever
}
// adafruit “logo” is shown on device 61
if(!oled_2.begin(SSD1306_SWITCHCAPVCC, 60)) {
Serial.println(“SSD1306 allocation2 failed”);
for(;;); // Don’t proceed, loop forever
}
cause it checks both adresses with a true or false statement.
And if the first one is true the second one cant be cause it still checks the first adress.
So its just gonna be stuck in the infinit loop when it comes to the second one.
Just write:
oled.begin(SSD1306_SWITCHCAPVCC, 0x3C);
oled_2.begin(SSD1306_SWITCHCAPVCC, 0x3D);
and you should be fine.
Thank you very much
Now I understand how to use Oled display in my projects.
Very usefull information.
Hi,
I use 128X64 OLED display in my project to display some parameters. I do not use Arduino, but I use XMC controller for the same. Everything is fine, but when I switch off and Switch on the Micro, the display is getting reset. Can you help me how can I keep te last display on the memory?
“bit_test” function is not available in SSD1306_ROMBMP
Hi.
What do you mean?
Regards,
Sara
Dear Rui Santos
Thank you for your site.
Sincerely yours,
Soonkoo Kwon
Thank you 🙂
How do I stop the logo bitmap from loading at startup on the ssd1306 using the ‘adafruit_ssd1306’ library?
Hello, great tutorial. I am having a problem, the screen seems to be displaying only a top stripe about 1/5 wide. I can see that the animation only occurs there, in the rest of the display there is only text I used in a previous animation with a different library (U8g2). How can I fix this?
Thank you, Daniel.
I also have this issue, just the top few lines seem to work, I believe it may be an issue with the library’s though. Help!
Hi.
Make sure the OLED display you’re using is an SSD1306 and that you’re passing the right I2C address to initialize the display.
You can check the I2C address of your display with this sketch: https://raw.githubusercontent.com/RuiSantosdotme/Random-Nerd-Tutorials/master/Projects/LCD_I2C/I2C_Scanner.ino
Regards,
Sara
Hi,
Congrats for the great content!
I have a motorbike odometer working fine with an arduino mini pro and a lcd 12864.
Now I wanted to reduce its footprint by using a smaller LCD and I’m trying these these examples in a ssd1306 with 128×32.
It is working great, but the “hello world” example consumes 82% of program storage space, leaving not enough space for the practical use I need.
Is there any way to reduce the storage space (by using some optimized font or other lib?), or will I need to move on to other microcontroller?
If other micro, what would be a suitable one? I don’t need wireless neither too many IOs, just more storage space…
Cheers,
João Silva, Portugal
Hello!
A very helpful pubilcation, but I have one question.
Even this publication is some years old, may I have the chance to rise a question. Is it possible to show a fixed text (not moving) and at the same to scroll a text some lines under the fixed text. Or can only the wohle display scrolled? Thanks in advance.
Greetings Christof Müller
Hi.
I’m not sure if that’s possible with the library’s built-in functions.
You may need to create your own functions to do that.
Regards,
Sara
Very complete guidelines for beginners and me. Thank you so much.
Hello,
is there a way to rotate text upside down?
Hello Sara & Rui!
Thank you very much for your Tutorials!
I do have a 128×64 oled display in blue/yellow, and the “Hello world”-example is running without problems.
What I intend to do is:
1. turn the display 180°, so the yellow part is down
2. create a graph/curve which shows values taken from a thermometer or a pressure sensor and slowly scrolls along the screen.
Can I somewhere find a list of all commands that are available for this lib?
Regards, Volker
If you are using the adafruit_SSD1306.h and the adafruit_GFX.h libraries, locate them in the Arduino/libraries directory. Look at the corresponding “.cpp” files for the list of public calls. This will give you an idea of what commands are available.
Hello Sara & Rui!
Thank you very much for your Tutorials!
The function “display.drawBitmap(x, y, Name, Width, Height,Color);” draw the bitmaps which are horizontal but I had many custom bitmaps which were vertical. is there any function to use those bitmaps or any way to convert them to horizontal ones?
Please help me. Does the OLED work in looping. For example:
while(1){
display.println(“test”);
display.display();
}
It shows text “test”, but the text keep copying down. Like,
test
test
test
test
Hi. I’m not sure I understood your issue.
Can you better explain?
Regards,
Sara
use display.setCursor(x,y); e.g. (0,10)
then print
it’s been years you still around
keep the good job…
tq.
Hey sara
Can you explain how we can add any other sensor instead of humidity sensor?
Like i want to add a water level sensor sl067 with oled.
Can you let me know how to fo that?
Thank you for the great step-by-step tutorial. I appreciate you walking us through each line of code. This was a great way to learn about using my new OLED screen.
I learned about the very useful PROGMEM keyword through your guide on bitmaps. If others ever have problems with the Arduino’s memory, look into saving storage space by using PROGMEM for arrays.
This gives me ideas for a cyberdeck I want to build. Love these tutorials.
Thanks TONS!!!
Hi Sara and Rui..
It is a comprehensive tutorial, and as beginner, I did learn much from it, many thanks.
Maybe I missed the content on how to shift a long text to the next line, with cut in the space, so every line (row) consist of full word and not cut in a part of word (by OLED pixel limit).
Please explain with a simple code example.
Thank you for your help.
There is a step missing, which can cause the generated array to throw a “too large” error. The missing step, which is shown in the image but not the text, is to set the Preset to Monochrome from the dropdown menu, before setting the type and scan direction.
Hi.
Thanks for pointing that out. I’ll highlight that option in the image.
Regards,
Sara
Hi, I am very green with Arduino and everything around it. I purchased the display board 1.3″ OLED Module: Bright White/Blue Display with 128×64 Resolution & I2C/SPI Communication and I want to connect it to an Arduino Nano board, can it be done?
Also I was wondering if there was an how to for using clock functions?
Hi, I am very green with Arduino and everything around it. I purchased the display board 1.3″ OLED Module: Bright White/Blue Display with 128×64 Resolution & I2C/SPI Communication and I want to connect it to an Arduino Nano board, can it be done?
Also I was wondering if there was an how to for using clock library functions?
thank you
Guy
Is there a way to read the OLED dimensions using a READ command
Thanks for a super good guide.
Can you use the new Arduino Uno Rev4 wifi for the same guide and if so, which Libraries should you use??
Hi, hallo.
Newest Arduino IDE, newest Versions of libraries.
THIS doesn’t work for me, cause in YOUR circuit you’ve selected the 5V-Output for the display.
THIS forced a compiling errorin adafruit_ssd1306.h line 148 (bool begin…)
The parameter ‘SSD1306_SWITCHCAPVCC’ is ONLY for the 3.3V output (to read also in the file itself – as comment).
I’m looking for the parameter if you use an EXTERNAL power source (5V or external Power-Adapter).
You can test it !
So long
Perlchamp
Sorry:
I use a nano V3…
I found, what i’m looking for:
begin():
Parameters:
vcs:
VCC selection. Pass SSD1306_SWITCHCAPVCC to generate the display voltage (step up) from the 3.3V source, or SSD1306_EXTERNALVCC otherwise. Most situations with Adafruit SSD1306 breakouts will want SSD1306_SWITCHCAPVCC.
addr
I2C address of corresponding SSD1306 display (or pass 0 to use default of 0x3C for 128×32 display, 0x3D for all others). SPI displays (hardware or software) do not use addresses, but this argument is still required (pass 0 or any value really, it will simply be ignored). Default if unspecified is 0.
reset
If true, and if the reset pin passed to the constructor is valid, a hard reset will be performed before initializing the display. If using multiple SSD1306 displays on the same bus, and if they all share the same reset pin, you should only pass true on the first display being initialized, false on all others, else the already-initialized displays would be reset. Default if unspecified is true.
periphBegin
If true, and if a hardware peripheral is being used (I2C or SPI, but not software SPI), call that peripheral’s begin() function, else (false) it has already been done in one’s sketch code. Cases where false might be used include multiple displays or other devices sharing a common bus, or situations on some platforms where a nonstandard begin() function is available (e.g. a TwoWire interface on non-default pins, as can be done on the ESP8266 and perhaps others).
Good luck !
So long
I have code here and I have some troubles with it.
It should show chess board on display.
There is code:
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_ADDR 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_ADDR);
void setup() {
Serial.begin(115200);
if (!display.begin(SSD1306_I2C, OLED_ADDR, &Wire)) {
Serial.println(F(“SSD1306 allocation failed”));
for (;;)
;
}
display.display(); // Zobrazí prázdný displej
delay(2000);
display.clearDisplay(); // Vymaže obsah displeje
drawChessboard();
}
void loop() {
// Váš loop kód zde
}
void drawChessboard() {
display.setTextSize(1);
display.setTextColor(SSD1306_WHITE);
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 8; j++) {
if ((i + j) % 2 == 0) {
display.fillRect(i * 16, j * 8, 16, 8, SSD1306_WHITE);
} else {
display.fillRect(i * 16, j * 8, 16, 8, SSD1306_BLACK);
}
}
}
display.display();
}
After Verify it show message: Compilation error: ‘SSD1306_I2C’ was not declared in this scope.
How can I fix it? Can you help me please.
Hi.
Use
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
instead of
if (!display.begin(SSD1306_I2C, OLED_ADDR, &Wire)) {
Regards,
Sara
You guys seem like you are well complimented, but I wanted to be the first in 2024… Great/clear/thorough tutorial Happy new year to the Santos family!
Hi.
Thank you so much.
We wish you a happy new year.
Regards,
Sara
Thank you for your tutorials.
I started to do this project as the aircon at the office is set a little too high (or cold, btw I’m from Australia and it is summer here).
Just wanted to see how cold it is getting at my desk. I am now trying to expand it to writing the data to an SD card but keep it as small as possible and run on a Lipo. I have a small tin ready to encase it as well.
Had to adjusted for the 128×32 display, DHT11 instead, but your tutorials are real easy to follow so no issue there.
I started this project on the Raspberry Pico but the Nano fits in the tin better.
Thanks again for all your work.
Hi
I am displaying the output of a BME680 on a oled display, I would like the screen to only be on when I press a button.
Please advise
Hi
Great tutorials for newbies.
Have followed a number of your tutorials etc. GREAT WORk😊
Quick question I have a number of ESP32 Boards with I2c and built (Glued)in 128 x 64 OLED. They are assigned different ESP32 ports for SCL and SDA, trying to find how I can reassign these via the Adafruit SSD1306.h. Library, thanks kindly I have spent a lot of time looking, probably been looking in the wrong place.🤣🤣🤣 Kind regards
Murray. N.Z
Hi.
We have a tutorial for a board like that.
Not sure if it’s exactly the same as your, but you can easily see how to change the pins if needed:
https://randomnerdtutorials.com/esp32-built-in-oled-ssd1306/
You may also find useful our I2C guide that explains how to use custom pins for I2C:
https://randomnerdtutorials.com/esp32-i2c-communication-arduino-ide/
I hope this helps.
Regards,
Sara
Thanks Sara
Perfect answer re I2c pin reassignment. I am now officially unstuck..! And back coding. Sincere thanks.
Murray Mc Govern
N.Z.
Great!
Thank you very much for this complete and perfect documentation.
Do you know if this library Adafruit GFX works for a very small screen oled of 0,42 inch with a display of 72*40 pixels?
If it has the SSD1306 driver, it should work.
Regards,
Sara
Thank you Sara
I tried with the driver SSD1306, and the library GFX, with the code of your documentation giving dimensions 72*40 and it did not work.
So I found a tutorial buydisplay and it’s the only code I found that works. github.com/olikraus/u8g2/files/3917804/ER-OLEDM0.42-1_Arduino_Tutorial.zip
I had also tried the U8g2 library, it didn’t work
Thanks for sharing.
Regards,
Sara