ESP32/ESP8266 MicroPython Web Server – Control Outputs

Learn how to build a web server to control the ESP32 or ESP8266 outputs using MicroPython framework. As an example we’ll build a web server with ON and OFF buttons to control the on-board LED of the ESP32/ESP8266. We’ll use sockets and the Python socket API.

esp32 web server with micropython on smartphone

Prerequisites

To program the ESP32 and ESP8266 with MicroPython, we use uPyCraft IDE as a programming environment. Follow the next tutorials to install uPyCraft IDE and flash MicroPython firmware on your board:

If this is your first time dealing with MicroPython you may find these next tutorials useful:

Parts required

For this tutorial you need an ESP32 or ESP8266 board:

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!

Preparing the Files

Connect the ESP32 or ESP8266 board to your computer. Open uPyCraft IDE, and go to Tools > Serial and select the serial port.

uPyCraft IDE selecting serial port

You should see the files on the ESP32/ESP8266 board on the device folder. By default, when you burn MicroPython firmware, a boot.py file is created.

For this project you’ll need a boot.py file and a main.py file. The boot.py file has the code that only needs to run once on boot. This includes importing libraries, network credentials, instantiating pins, connecting to your network, and other configurations.

The main.py file will contain the code that runs the web server to serve files and perform tasks based on the requests received by the client.

Creating the main.py file on your board

  1. Press the “New file” button to create a new file.

  1. Press the “Save file” button to save the file in your computer.

  2. A new window opens, name your file main.py and save it in your computer:

  1. After that, you should see the following in your uPyCraft IDE (the boot.py file in your device and a new tab with the main.py file):

  1. Click the “Download and run” button to upload the file to your ESP board:

  1. The device directory should now load the main.py file. Your ESP has the file main.py stored.

uPycraft IDE creating main.py file

boot.py

Copy the following code to the ESP32/ESP8266 boot.py file.

# Complete project details at https://RandomNerdTutorials.com

try:
  import usocket as socket
except:
  import socket

from machine import Pin
import network

import esp
esp.osdebug(None)

import gc
gc.collect()

ssid = 'REPLACE_WITH_YOUR_SSID'
password = 'REPLACE_WITH_YOUR_PASSWORD'

station = network.WLAN(network.STA_IF)

station.active(True)
station.connect(ssid, password)

while station.isconnected() == False:
  pass

print('Connection successful')
print(station.ifconfig())

led = Pin(2, Pin.OUT)

View raw code

As mentioned previously, we create our web server using sockets and the Python socket API. The official documentation imports the socket library as follows:

try:
  import usocket as socket
except:
  import socket

We need to import the Pin class from the machine module to be able to interact with the GPIOs.

from machine import Pin

After importing the socket library, we need to import the network library. The network library allows us to connect the ESP32 or ESP8266 to a Wi-Fi network.

import network

The following lines turn off vendor OS debugging messages:

import esp
esp.osdebug(None)

Then, we run a garbage collector:

import gc
gc.collect()

A garbage collector is a form of automatic memory management. This is a way to reclaim memory occupied by objects that are no longer in used by the program. This is useful to save space in the flash memory.

The following variables hold your network credentials:

ssid = 'REPLACE_WITH_YOUR_SSID'
password = 'replace_with_your_password'

You should replace the words highlighted in red with your network SSID and password, so that the ESP is able to connect to your router.

Then, set the ESP32 or ESP8266 as a Wi-Fi station:

station = network.WLAN(network.STA_IF)

After that, activate the station:

station.active(True)

Finally, the ESP32/ESP8266 connects to your router using the SSID and password defined earlier:

station.connect(ssid, password)

The following statement ensures that the code doesn’t proceed while the ESP is not connected to your network.

while station.isconnected() == False:
  pass

After a successful connection, print network interface parameters like the ESP32/ESP8266 IP address – use the ifconfig() method on the station object.

print('Connection successful')
print(station.ifconfig())

Create a Pin object called led that is an output, that refers to the ESP32/ESP8266 GPIO2:

led = Pin(2, Pin.OUT)

main.py

Copy the following code to the ESP32/ESP8266 main.py file.

# Complete project details at https://RandomNerdTutorials.com

def web_page():
  if led.value() == 1:
    gpio_state="ON"
  else:
    gpio_state="OFF"
  
  html = """<html><head> <title>ESP Web Server</title> <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" href="data:,"> <style>html{font-family: Helvetica; display:inline-block; margin: 0px auto; text-align: center;}
  h1{color: #0F3376; padding: 2vh;}p{font-size: 1.5rem;}.button{display: inline-block; background-color: #e7bd3b; border: none; 
  border-radius: 4px; color: white; padding: 16px 40px; text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}
  .button2{background-color: #4286f4;}</style></head><body> <h1>ESP Web Server</h1> 
  <p>GPIO state: <strong>""" + gpio_state + """</strong></p><p><a href="/?led=on"><button class="button">ON</button></a></p>
  <p><a href="/?led=off"><button class="button button2">OFF</button></a></p></body></html>"""
  return html

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('', 80))
s.listen(5)

while True:
  conn, addr = s.accept()
  print('Got a connection from %s' % str(addr))
  request = conn.recv(1024)
  request = str(request)
  print('Content = %s' % request)
  led_on = request.find('/?led=on')
  led_off = request.find('/?led=off')
  if led_on == 6:
    print('LED ON')
    led.value(1)
  if led_off == 6:
    print('LED OFF')
    led.value(0)
  response = web_page()
  conn.send('HTTP/1.1 200 OK\n')
  conn.send('Content-Type: text/html\n')
  conn.send('Connection: close\n\n')
  conn.sendall(response)
  conn.close()

View raw code

The script starts by creating a function called web_page(). This function returns a variable called html that contains the HTML text to build the web page.

def web_page():

The web page displays the current GPIO state. So, before generating the HTML text, we need to check the LED state. We save its state on the gpio_state variable:

if led.value() == 1:
  gpio_state="ON"
else:
  gpio_state="OFF"

After that, the gpio_state variable is incorporated into the HTML text using “+” signs to concatenate strings.

html = """<html><head> <title>ESP Web Server</title> <meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="icon" href="data:,"> <style>html{font-family: Helvetica; display:inline-block; margin: 0px auto; text-align: center;}
h1{color: #0F3376; padding: 2vh;}p{font-size: 1.5rem;}.button{display: inline-block; background-color: #e7bd3b; border: none; 
border-radius: 4px; color: white; padding: 16px 40px; text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}
.button2{background-color: #4286f4;}</style></head><body> <h1>ESP Web Server</h1> 
<p>GPIO state: <strong>""" + gpio_state + """</strong></p><p><a href="/?led=on"><button class="button">ON</button></a></p>
<p><a href="/?led=off"><button class="button button2">OFF</button></a></p></body></html>"""

Creating a socket server

After creating the HTML to build the web page, we need to create a listening socket to listen for incoming requests and send the HTML text in response. For a better understanding, the following figure shows a diagram on how to create sockets for server-client interaction:

python socket server and client

Create a socket using socket.socket(), and specify the socket type. We create a new socket object called s with the given address family, and socket type. This is a STREAM TCP socket:

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

Next, bind the socket to an address (network interface and port number) using the bind() method. The bind() method accepts a tupple variable with the ip address, and port number:

s.bind(('', 80))

In our example, we are passing an empty string ‘ ‘ as an IP address and port 80. In this case, the empty string refers to the localhost IP address (this means the ESP32 or ESP8266 IP address).

The next line enables the server to accept connections; it makes a “listening” socket. The argument specifies the maximum number of queued connections. The maximum is 5.

s.listen(5)

In the while loop is where we listen for requests and send responses. When a client connects, the server calls the accept() method to accept the connection. When a client connects, it saves a new socket object to accept and send data on the conn variable, and saves the client address to connect to the server on the addr variable.

conn, addr = s.accept()

Then, print the address of the client saved on the addr variable.

print('Got a connection from %s' % str(addr))

The data is exchanged between the client and server using the send() and recv() methods.

The following line gets the request received on the newly created socket and saves it in the request variable.

request = conn.recv(1024)

The recv() method receives the data from the client socket (remember that we’ve created a new socket object on the conn variable). The argument of the recv() method specifies the maximum data that can be received at once.

The next line simply prints the content of the request:

print('Content = %s' % str(request))

Then, create a variable called response that contains the HTML text returned by the web_page() function:

response = web_page()

Finally, send the response to the socket client using the send() and sendall() methods:

conn.send('HTTP/1.1 200 OK\n')
conn.send('Content-Type: text/html\n')
conn.send('Connection: close\n\n')
conn.sendall(response)

In the end, close the created socket.

conn.close()

Testing the Web Server

Upload the main.py and boot.py files to the ESP32/ESP8266. Your device folder should contain two files: boot.py and main.py.

After uploading the files, press the ESP EN/RST on-board button.

esp32 enable button

After a few seconds, it should establish a connection with your router and print the IP address on the Shell.

Open your browser, and type your ESP IP address you’ve just found. You should see the web server page as shown below.

esp32 web server control outputs

When you press the ON button, you make a request on the ESP IP address followed by /?led=on. The ESP32/ESP8266 on-board LED turns on, and the GPIO state is updated on the page.

Note: some ESP8266 on-board LEDs turn on the LED with an OFF command, and turn off the LED with the ON command.

web server on smartphone and esp32

When you press the OFF button, you make a request on the ESP IP address followed by /?led=off. The LED turns off, and the GPIO state is updated.

Note: to keep this tutorial simple, we’re controlling the on-board LED that corresponds to GPIO 2. You can control any other GPIO with any other output (a relay, for example) using the same method. Also, you can modify the code to control multiple GPIOs or change the HTML text to create a different web page.

Wrapping Up

This tutorial showed you how to build a simple web server with MicroPython firmware to control the ESP32/ESP8266 GPIOs using sockets and the Python socket library. If you’re looking for a web server tutorial with Arduino IDE, you can check the following resources:

If you’re looking for more projects with the ESP32 and ESP8266 boards, you can take a look at the following:

We hope you’ve found this article about how to build a web server with MicroPython useful. To learn more about MicroPython, take a look at our eBook: MicroPython Programming with ESP32 and ESP8266.



Learn how to build a home automation system and we’ll cover the following main subjects: Node-RED, Node-RED Dashboard, Raspberry Pi, ESP32, ESP8266, MQTT, and InfluxDB database DOWNLOAD »
Learn how to build a home automation system and we’ll cover the following main subjects: Node-RED, Node-RED Dashboard, Raspberry Pi, ESP32, ESP8266, MQTT, and InfluxDB database DOWNLOAD »

Enjoyed this project? Stay updated by subscribing our newsletter!

102 thoughts on “ESP32/ESP8266 MicroPython Web Server – Control Outputs”

  1. Hello Sara,

    this explanation is pretty detailed. IMHO it is a good compromise between explaining it all from scratch and “drop a short textline”

    I want to make some suggestions how to improve the explanation.
    Add “ESP32” to word “server” and the words “your smartphone, tablet or PC” to the word “client” at the grafic which shows the steps what server and client are doing.

    The result a webpage that can be clicked to switch on/off a LED is impressing. To achieve this a lot of code-technologies have to be used. I don’t want to suggest explain all
    – server-client,
    – TCP/IP,
    – sockets,
    – HTML
    all from scratch. That would inflate the explanation much too much.

    But there are a few places where a small effort gives pretty much more insight into using all these coding-technologies.

    I mean find a way that the parts of the html-code that defines the buttons and the text on the buttons is very easy to find and easy to modify.

    Another way could be using some kind of a website-editor, if there exists one that is easy to use. By “easy to use” I mean a software that is very very similar to an office-software or at least very very intuitive to use.
    So that one hour of learning is enough to create a website-variation of your demo that has three buttons and a slider.

    Then showing how the html-code-output of this software is implemented into the python-code by copy and paste.

    best regards

    Stefan

    Reply
    • Hi Stefan.
      Thank you for your suggestions. We’ll take those into account when writing new posts about this subject.
      Also, I’ll try to improve this article when I have the chance.
      Thank you.
      Regards,
      Sara 🙂

      Reply
  2. Hi Rui,
    I have Linux Mint 19 based on ubuntu … uPyCraft IDE doesn’t work … Is there another way or an improvement pf uPyCraft IDE ?
    Thank you

    Reply
    • Hi Bernard.
      uPyCraft should work on your system if you compile it yourself: github.com/DFRobot/uPyCraft_src
      If you compile it, it should work.
      Note: you don’t need to use uPycraft IDE, you can program program the board with a serial connection using REPL or webREPL.
      Regards,
      Sara 🙂

      Reply
  3. Dear, I’have a lot of problem to use this app with Safari or Google Chrome for iPhone. If I use Google Chrome for mac I don’t have any problem, but when I use Safari I can’t open the page. I see the serial, and I can read the connection by computer to ESP32, but the browser don’t open the contents. Also on Android and Google Chrome all works.

    Reply
    • Hi Giovanni.
      I’m sorry to hear that.
      I actually didn’t test the web server on Safari or iPhone. I’ll try to figure out what happens.
      Meanwhile, if you find what causes the problem, just let us know.
      Regards,
      Sara 🙂

      Reply
  4. good article as usual 🙂
    My question though is why or when would you use python instead of the Arduino ide? What are the benefits etc.
    Also I agree with Stefan on the editor HTML thing might be helpful.

    Reply
    • Hi Bob.
      I think both are good ways to program the ESP32.
      MicroPython is much simpler to program, it supports a REPL (Read-Evaluate-Print Loop). The REPL allows you to connect to a board and execute code quickly without the need to compile or upload code.
      It also gives you a better overview of the files stored on the ESP32. Uploading code to the ESP32 is much faster with MicroPython.
      In terms of libraries for sensors and modules, at the moment there is more support for Arduino IDE.
      Regards,
      Sara 🙂

      Reply
  5. Works perfect on my old laptop ( Ubuntu ) using Chromium or Firefox . Doesn’t work on my IPhone 5S ( tried Safari and Chromium ) . EFM ( electronics F…… magic) ..
    Thanks anyway , great tutorial , step by step explained , Great Job !
    Bob

    Reply
  6. I made a printscreen with the result of “request = conn.recv(1024)” . First logon is the laptop , 2nd one is the Phone . I can mail it if you want it . Thanks again , keep up the good job !
    Bob

    Reply
  7. Did Some research and tried different browsers on my. IPhone .
    Puffin browser replied : Error 102
    (net:: ERR_CONNECTION_REFUSED) when loading URL http://(IP-adress)
    Hope this is a clue ….
    Thanks a lot and keep up the good job !
    Bob

    Reply
  8. I think I followed the steps correctly but when I try to run it I get error messages:

    main.py:4: undefined name ‘led’
    main.py:18: undefined name ‘socket’
    main.py:18: undefined name ‘socket’
    main.py:18: undefined name ‘socket’
    main.py:32: undefined name ‘led’
    main.py:35: undefined name ‘led’

    Any suggestions what I’m doing wrong?

    Thank you.

    Reply
  9. Found a working script for the IPhone , out of the box from the official micropython site :
    https://docs.micropython.org/en/latest/esp8266/tutorial/network_tcp.html#simple-http-server
    I modified boot.py a little ( removed double imports ) , works perfect 🙂
    these lines ( “arduino style”) make the difference I think …
    line = cl_file.readline()
    if not line or line == b’\r\n’:
    Anyway , thanks a lot for helping people to become decent programmers 🙂
    Love you guys , lots of greetings from Belgium ,
    Bob

    Reply
    • Hi Jaroslav.
      In the while loop, after receiving a request, we need to check if the request contains the ‘/?led=on’ or ‘/?led=on’ expressions. For that, we can apply the find() method on the request variable. the find() method returns the lowest index of the substring we are looking for.

      Because the substrings we are looking for are always on index 6, we can add an if statement to detect the content of the request. If the led_on variable is equal to 6, we know we’ve received a request on the /?led=on URL and we turn the LED on.
      If the led_off variable is equal to 6, we’ve received a request on the /?led=off URL and we turn the LED off.

      I hope my explanation is clear.
      Regards,
      Sara 🙂

      Reply
  10. Hi
    Many thanks for your work
    Following this article works fine. But there is tow questions
    The program stops at “conn, addr = s.accept()” waiting for a request, and it can wait for ever.
    Is it possible just to check if there is one and if there is not continue the loop and the check again the next loop. If this is possible you can use the micro controller for other task in between the requests as in the Arduino env
    When connecting with Chrome, on PC or phone, the connection are busy for ever if you do not close the browser
    The server hangs printing Got a connection from (‘192.168.1.193’, 54536) and you can not use any other computer or browser untill it is closed, not just the tab but the whole browser.
    Connecting the a Raspberry pi works fine.
    As it works on RPi it seems to be the PC/phone or Chrome that is the problem. Is there something to do about this. It happen that you forget to close the window and then is it impossible to aces the serve from an other place

    Reply
    • Hi Hans.
      You are right.
      But I don’t think it is something to do with the code. Because when we first implemented this, it worked fine supporting several clients at the same time.
      It seems that google Chrome opens two connections, leaving the second one opened. So we are not able to listen requests from other clients while that connection is opened.
      I don’t know why this is happening, but we’re working to find a solution.
      If you know a workaround for this, please share with us.
      Thank you for your comment.
      Regards,
      Sara

      Reply
      • Dear Sara,
        thanks for the great tutorial it helped me a lot.

        I have the same issue with like Hans explained:
        “The program stops at “conn, addr = s.accept()” waiting for a request, and it can wait for ever.”

        Is there a chance to check the content of s.accept() and branch out in case of “empty”.
        I need to measure temperature and show to a display in as well.

        thanks Juergen

        Reply
        • Hi Juergen, or anyone else wishing to achieve the same… temperature and screen refresh as a timer loop on my ESP32, so this runs at the same time as the loop waiting for requests.

          I am also however currently struggling with google chrome especially as my script doesn’t always generate a response, it will often error closing the connection without a response being sent.

          would be interested if anyone has found a solution to this, I will try and update if i do myself.

          Reply
          • Hi Sara, Luke, all,

            i have it solved in following way:
            – created a ISR (interupt service routine) triggered by machine.timer(0)
            – f.e. each 2 seconds the routine is stepping out performing my requested task and returning to the accept() position

            Init code:

            #Timer Interrupt
            tim0 = machine.Timer(0)
            tim0.init(period=2000, mode=machine.Timer.PERIODIC, callback=handle_callback)

            Main code:

            Timer Interrupt Routine

            def handle_callback(timer):
            ….# your functions to call

            I’m surprised how good that works; might it’s not professional, but it is doing what it should.

            kind regards
            Jürgen

          • Jurgen / All,

            I done this the same way using the timer to update my screen, works great for me.. I was also working on this for while yesterday and discovered a few things which have made a big difference in the reliably if receiving a response (tested on Chrome for Windows and Android).

            Used the replay method from the Micropython.org example as mentioned by Bob in a previous comment:
            response = HTML
            conn_file = conn.makefile(‘rwb’, 0)
            conn.send(‘HTTP/1.0 200 OK\r\nContent-type: text/html\r\n\r\n’)
            conn.send(response)
            conn.close()

            Used _Thread to run multiple threads with s.accept. I put the whole Socket Script into a Function and call it from both a secondary and main thread. I actually found this on a tutorial for the Pi Pico, but it worked fine on my ESP32.
            import _thread

            I’m so glad to see these comments are still ative.

  11. As usual, this was a great tutorial. Took me a couple of times to get it to come together. I have a Heltec wifi 32 with oled and wanted the oled to tell me what ip I was connected to. Has anyone else complained that the Upycraft ide crashes windows 10?

    Reply
  12. Hi Sara, Rui
    Thanks so much for this tutorial. I tried it as it out as my first project after I setup my ESP32 with micropython. The code is beautifully explained and worked first time for me

    John

    Reply
  13. Hello Sara,

    I cannot connect to the server. I am using a Mobile shared connection of Android

    When I type ifconfig in the Micropython Terminal I have the following error message :
    NameError: name ‘ifconfig’ isn’t defined

    When I add :
    “print(‘Connection successful’)
    print(station.ifconfig())”
    to the main.py and run the code I get this message error :
    NameError: name ‘station’ isn’t defined

    Thanks for your help and good nob by the way the tuto is nice
    Cheers
    Julien

    Reply
    • Hi Julien.
      Have you uploaded the boot.py file before? The boot.py imports the required libraries and that seems to be an issue regarding not having the libraries imported.
      Make sure you upload the boot.py first or that you copy all the content of the boot.py file to the main.py file to make it work.
      I hope this helps.
      Regards,
      Sara

      Reply
      • Hi Sarah, I have try again with the boot inside my main.py and it seems to works except that the REPL does not write any IP adresse (Once more I am on cellphone hotpost) and “connection successful” but something unwridable :

        dc|{cc’ndoo#p$sl{dxnlcg|dcnn

        I use a ESP8266 D1 mini and upycraft. And thanks a lot for your previous fast answer !

        Cheers
        Julien

        Reply
  14. Hi Sara

    An excellent tutorial. I used Thonny as the IDE as uPyCraft was causing me problems. However i did have a issue:

    NameError: name ‘led’ isn’t defined
    NameError: name ‘socket’ isn’t defined

    This I believe is due to the boot.py and main.py are not running in the same namespace which I assume is Thonny 3.2.7 issue. Any thoughts on this?
    NameError: na me ‘led’ isn’t defined
    NameError: name ‘socket’ isn’t defined

    I solved the problem by moving everything in the boot.py apart from
    import uos, machine
    import gc
    gc.collect()

    into the main.py

    Note with Thonny you have to use “Stop” button before “run the current script” again or you get a OSError: [Errno 98] EADDRINUSE

    Regards
    Steve

    Reply
  15. Hi Sara
    I have some problems whit the code. I’m using uPycraft v1.0 and when I teste the code in main.py, some lines are wrong. I don’t know if this problem is due the version of the program. And other problem with Testing the Web Server; when I press the EN buttom, my esp32 lose the firmware and can’t create the web server. When I check the sintax, this problems come up

    *main.py:2: undefined name ‘led’
    *main.py:16: undefined name ‘socket’
    *main.py:16: undefined name ‘socket’
    *main.py:16: undefined name ‘socket’
    *main.py:30: undefined name ‘led’
    *main.py:33: undefined name ‘led’
    syntax finish.

    Thank’s very much.
    Eduardo

    Reply
      • I tried, but it does not function. The message ‘ Connection successful
        (‘192.168.4.1’, ‘255.255.255.0’, ‘192.168.4.1’, ‘0.0.0.0’) ‘ does not show up. When I press the EN button the firmware is deleted. I tried the MicroPython: ESP32/ESP8266 Access Point (AP) tutorial, and this got right.
        Regards,
        Eduardo

        Reply
  16. Great There is also a nice web server on MicroPython that also allows you to do “real-time” with WebSockets :
    v1 : github.com/jczic/MicroWebSrv
    v2 : github.com/jczic/MicroWebSrv2 (new)
    🙂

    Reply
  17. I’m curious about how to use usocket with a slider, to pass the value to a function. I’m looking to change the PWM duty cycle through that, to control the brightness of an LED.

    Reply
      • I managed to work out a way of doing what I wanted. The issue I had to tackle was that the HTML button causes the page to reload, meaning that the slider resets to defaults, I wanted it to stay the same. Using a short script and ‘onclick’ for the buttons and ‘oninput’ for the slider I can get it to work without reloading. The xhttp function can then pass a value to the rest of the python script which can then be parsed to control, in my case, 4 channels of lighting with the slider working as a dimmer. Even once you have set the colour mix from the buttons, the slider will act as a simple dimmer. I can share code for this, although it’s probably a bit untidy now. I made the HTML part a separate file, also the lightcontrol function.

        Reply
        • Hi, I’m trying to accomplish the same goal of getting values without having to reload. Would you mind uploading your code to the pastebin Sara commented about? I think if I can even just see the code, that would be enough for me to reverse engineer it (though if you want to include an explanation, I wouldn’t mind that either haha).

          Thanks!!

          Reply
  18. Hello,

    Great tutorial. I’ve been playing around with this Tuto and the one with relays/webserver. Everything works, when i browse to the web server address and the on/off buttons work. But the problem is that I’m unable to view the web server page from a mobile device.

    Do you have an suggestions?

    Reply
  19. Non-Blocking connection
    What i would like to do is to do an analogue read and update the web page with its value. However the current code waits for a connection before before carrying out any action so a pot_value = pot.read() will only get carried out one the web page a GET is executed. Does anyone have any idea how to get micropython to check for a connection i.e. GER#T sent and if not then to continue to foe example read the analogue value and update the web page. I can do this easily in Arduino with webSocket.onEvent(webSocketEvent). Is there an equivalent in micropython
    Thank you Steve

    Reply
  20. Just dropping some love for this tutorial in 2020. Everything works, and I’m super happy I learned about UPyCraft. Thanks!!!

    Reply
  21. As per the tutorial, I copy boot.py into ESP32.
    Now I could not connect my ESP32 with any IDE.

    I got error like,

    Device is busy or does not respond. Your options:

    wait until it completes current work;
    use Ctrl+C to interrupt current work;
    use Stop/Restart to interrupt more and enter REPL.

    ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
    Could not enter REPL. Trying again with 1 second waiting time…
    Could not enter REPL. Trying again with 3 second waiting time…
    Could not enter REPL. Trying again with 5 second waiting time…
    Could not enter REPL. Giving up. Read bytes:
    b”

    Your options:

    check connection properties;
    make sure the device has suitable firmware;
    make sure the device is not in bootloader mode;
    reset the device and try again;
    try other serial clients (Putty, TeraTerm, screen, …);
    ask for help in Thonny’s forum or issue tracker.

    Backend terminated or disconnected. Use ‘Stop/Restart’ to restart.

    I couldn’t find any solution.
    I want to factory reset or change boot.py file but my ESP32 never go into boot mode.

    if you have any solution please let me know.
    Thank You.

    Reply
      • Thank you for your reply.
        ESP32 detected in Device manager on COM7 but not detected on esptool.
        error is,
        ‘esptool.py’ is not recognized as an internal or external command,
        operable program or batch file.
        Regards,
        Yash Patel

        Reply
        • Hi,
          I get this error too with ESP32 boards, but very rarely with ESP8266.
          I read somewhere that the ESP32/MicroPython thing isn’t as mature or stable yet, so that could be the problem.
          In fact, have 4 ESP32 boards and while they are all fine with Arduino, only one of them (from M5Stack) works reliably with MicroPython.
          Seems the cheap clones are more prone to giving this error. My solution – buy branded boards (M5Stack, DFrobot etc) or use ESP8266
          Hope that helps

          Reply
  22. The tutorial states that garbage collection frees up flash memory:

    “This is useful to save space in the flash memory”

    This is not true. Garbage collection happens as runtime and affects ram only.

    Reply
  23. Hello Sara,
    your job is very well done, I admire your simplicity in explaining complex things.

    I created a Tkinter interface to drive all my iTOs with a raspberry, and I cannot directly send my instrauctions from my raspberry to my esp8266.

    my project is to set up a weather station and, depending on the data, retrieve from the web, open or close the shutters of the house.

    For example .

    Thanks for your help

    Cdlt.

    JackRay

    Reply
  24. if led_on == 6:
    print(‘LED ON’)
    led.value(1)
    if led_off == 6:
    print(‘LED OFF’)
    led.value(0)
    why we use 6 in every condition?

    Reply
  25. Hi, thanks for the detailed tutorial. I’m using the esp32. I think I may have a bug. I get a “TypeError: object with buffer protocol required” error message for the “conn.sendall(response)” line at the end of the main.py code. I’m using MicroPython v1.17. When I go to the webpage by entering the IP address of the esp32 then it loads a page with the two buttons. I can click a button and another, say the “on” then the “off” button, then after clicking the second button it gives me the aforementioned error. Any idea what may be doing the error?

    Reply
  26. Hi Sara, Rui,

    Thanks for this tutorial.
    I startet with the LED blink example and could get it running on a ESP32 Devkit C v4.

    When I try the webserver control outputs example I get following messages (I did change SSID and password in boot.py to my credentials):
    rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
    configsip: 0, SPIWP:0xee
    clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
    mode:DIO, clock div:2
    load:0x3fff0008,len:8
    load:0x3fff0010,len:3408
    load:0x40078000,len:9488
    load:0x40080000,len:252
    entry 0x40080034
    [0;32mI (1994) cpu_start: Pro cpu up.[0m
    [0;32mI (1994) cpu_start: Single core mode[0m
    [0;32mI (1996) heap_alloc_caps: Initializing. RAM available for dynamic allocation:[0m
    [0;32mI (2008) heap_alloc_caps: At 3FFAFF10 len 000000F0 (0 KiB): DRAM[0m
    [0;32mI (2029) heap_alloc_caps: At 3FFB3000 len 00005000 (20 KiB): DRAM[0m
    [0;32mI (2050) heap_alloc_caps: At 3FFBBB28 len 00002000 (8 KiB): DRAM[0m
    [0;32mI (2070) heap_alloc_caps: At 3FFE0A18 len 000035E8 (13 KiB): D/IRAM[0m
    [0;32mI (2092) heap_alloc_caps: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM[0m
    [0;32mI (2113) heap_alloc_caps: At 4009457C len 0000BA84 (46 KiB): IRAM[0m
    [0;32mI (2134) cpu_start: Pro cpu start user code[0m
    [0;32mI (2194) cpu_start: Starting scheduler on PRO CPU.[0m
    [0;32mI (2618) modsocket: Initializing[0m
    I (2618) wifi: wifi firmware version: 72ddf26
    I (2618) wifi: config NVS flash: enabled
    I (2618) wifi: config nano formating: disabled
    [0;32mI (2618) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE[0m
    [0;32mI (2628) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE[0m
    I (2648) wifi: Init dynamic tx buffer num: 32
    I (2648) wifi: Init dynamic rx buffer num: 64
    I (2648) wifi: wifi driver task: 3ffb7b70, prio:23, stack:4096
    I (2648) wifi: Init static rx buffer num: 10
    I (2658) wifi: Init dynamic rx buffer num: 0
    I (2658) wifi: Init rx ampdu len mblock:7
    I (2668) wifi: Init lldesc rx ampdu entry mblock:4
    I (2668) wifi: wifi power manager task: 0x3ffe63ac prio: 21 stack: 2560
    I (2678) wifi: wifi timer task: 3ffe7424, prio:22, stack:3584
    [0;32mI (2698) phy: phy_version: 355.1, 59464c5, Jun 14 2017, 20:25:06, 0, 0[0m
    I (2698) wifi: mode : null
    Traceback (most recent call last):
    File “boot.py”, line 15, in
    AttributeError: ‘module’ object has no attribute ‘osdebug’

    line 14 and 15 in boot.py are as follows:
    import esp
    esp.osdebug(None)

    Reply
    • I commented the line esp.osdebug(None) and it seems to connect.
      What is it supposed to do? Provide some methods for debugging?

      Best regards,
      Roger

      Reply
  27. hello,
    I recommend to use this portion of code right before creation of the socket:
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    or else you will have sometimes the error: “OSError: [Errno 98] EADDRINUSE”

    Reply
  28. Hello Sara, I have setup the web server on ESP32 and it works great to turn On/Off onboard LED without any issue at all. But there is one issue I’m facing i.e. after sometime the ESP board hangs-up and doesn’t show the web page when try to send On/Off command again. It doesn’t respond and not connect to board. After resetting the board it works again and open the On/Off web page. I need to have reset the board every time after sometime to make the web page work. How to fix this issue? Thanks.

    Reply
  29. Hello Sara,
    I have setup the web server on ESP32 and it works great to turn On/Off onboard LED without any issue at all. But there is one issue I’m facing i.e. after sometime the ESP board hangs-up and doesn’t show the web page when try to send On/Off command again. It doesn’t respond and not connect to board. After resetting the board it works again and open the On/Off web page. I need to have reset the board every time after sometime to make the web page work. How to fix this issue? Thanks.

    Reply
  30. Hello Sara,
    Great tutorial, this is the second ESP32 tutorial i follow and it was very detailed. I struggled a bit to find a tutorial like this, that goes step by step and explaining everything. Very good for begginers like me.
    In the webserver tutorial everything seems to work fine, i get connection successfull and the details of the connection (browser, device…) however the webpage does not load, what could be causing this issue?
    Thank you in advance.
    Best regards,
    João

    Reply
    • Use setInterval() method. e.g.

      setInterval(function(){ websocket.send(“X” + String(Joy3.GetX())); }, 100);

      In this case I am getting a value from a javascript joystick every 100ms. Note if you make the interval to short and the ESP cannot fully process the request, then it will hang or I should say not do as expected

      Reply
  31. Hello,

    Just wondering how I could add and LED position to the url?

    ex. 11.11.111.11/?ledPosition=5&led=on

    Would love to be able to turn on a specific LED (one at at time) with a url request and something like below from MicroPython addressable LED page: https://randomnerdtutorials.com/micropython-ws2812b-addressable-rgb-leds-neopixel-esp32-esp8266/

    #number of total leds
    n = 50

    #pin 2
    p = 2

    #specific Led to light up
    ledPosition = 7

    np = neopixel.NeoPixel(machine.Pin(p), n)

    np[ledPosition] = (255, 0, 0)
    np.write()

    Reply
  32. Just wanted to add that I’m getting a status 500 error:

    System.Net.WebException: The server committed a protocol violation. Section=ResponseStatusLine

    from the response from the ESP8266, any thoughts?

    Reply
  33. Great tutorial and it works. But I think the line

    request = str(request)

    is not exactly what you intended. This gives a string of the form b’GET…. (note the leading b’)

    You probably intended something like
    request = request.decode()
    to convert from bytearray to string.

    Reply
  34. After few minutes i open the website, i get this error: OSError: [Errno 104] ECONNRESET
    Please how to solve that issue?

    Reply
  35. Hi Sara,
    Great tutorial! Easy to follow and it works well.

    Any idea on how to serve images? I’ve uploaded images, and the html debug gives a 200 code, but they don’t display…

    Thanks

    Reply
  36. this web server and client must be in same local network, right?
    could control/get its state via Internet ? if not, what other protocol needs ?

    Reply

Leave a Comment

Download Our Free eBooks and Resources

Get instant access to our FREE eBooks, Resources, and Exclusive Electronics Projects by entering your email address below.