Python is one of the best programming languages around, it’s easy and efficient. Let’s leave c/c++ behind and program NodeMCU with Python. See how.

Intro

Most probably you were programming NodeMCU with Arduino platform (Arduino Language in other words).

Similarly, there is MicroPython Framework using that you can program NodeMCU to the full extent. For that, you have to follow these steps,

Steps overview

  1. Download firmware file for ESP8266 board.
  2. Flash NodeMCU with the firmware file using a tool NodeMCU Flasher.
  3. Download IDE for programming or program directly through Serial (Not recommended).
  4. Learn the basics of MicroPython.

Flashing the Firmware

1. Downloading the firmware

Open up the MicroPython website and go to download section — http://micropython.org/download.

You will find firmware for few popular boards, go to “Firmware for ESP8266 boards” (NodeMCU is based in esp8266 board) and download the latest version (that is at the top).

Downloading MicroPython firmware form MicroPython official site
Downloading MicroPython firmware form MicroPython official site

2.Flashing the Firmware

Using NodeMCU Flasher (On Windows only)

This is the simplest tool to flash ESP8266 boards.

  1. To flash downloaded (or any firmware to NodeMCU), download NodeMCU Flasher Directly from here.
  2. Open NodeMCU Flasher. Select a port where NodeMCU is connected.
  3. Go to config tab and paste the location of firmware file (without quotes).
  4. Flash from Operation tab by clicking Flash.

Using esptool (Windows, Linux, Mac)

This is a cross platform tool. It’s actually a python script.

  1. Install python if not already installed From here.
  2. Install esptool from
    Command prompt or PowerShell in Windows
    Terminal in Linux and Mac
    Type
   pip install esptool
  1. Erase the flash on esp8266
   python -m esptool --port <port> erase_flash

Where <port> is the port where NodeMCU is connected You can check which port it’s connected in Arduino IDE.

  1. Now flash the firmware
python -m esptool --port <port> --baud 460800 write_flash --flash_size=detect -fm dio 0 <firmware_file_location>

If errors like espcomm_mem_failed occur, change the baud rate by replacing “–baud 460800” to sometimes like “–baud 115200” or “–baud 9600”.

NOTE – Some NodeMCU variants may not require “-fm dio” option or try which method works for you.

Where <port> is the port where NodeMCU is connected.

3.Programming

Here comes the coolest part, programming MicroPython is the easiest.

Two ways to program

1. Using REPL

REPL over the Serial Port

Just fire up the Arduino IDE open Serial Monitor set baud rate to 115200 and line ending to Carriage Return or Both NL or CR.

Arduino Serial Monitor - MicroPython
Arduino Serial Monitor – MicroPython

Now just type python codes as you do in Python command line.
Try this code,

pin = machine.Pin(2, machine.Pin.OUT) # Inbuilt LED pin, GPIO02
pin.value(0) # Turn On the LED
pin.value(1) # Turn Off
#OR
pin.off()
pin.on()

WebREPL — Prompt over Wi-Fi

After fresh install, the device will open Wi-Fi Access Point (AP), with ESSID MicroPython- with password “micropythoN”, no need to go more here we will configure this with Serial prompt, it’s easier.

By Uploading files.

You can just place python files like any other files on your PC, including folders (Yippee).

For that, we need to configure MicroPython so it will connect to your Wi-Fi and enable WebREPL (disabled initially for security reason)

Configuration

Using Serial Prompt, type this

import network
# STA_IF Interface (Station Interface)
sta_if = network.WLAN(network.STA_IF)
# Activate station interface:
sta_if.active(True)
# Then connect to your Wi-Fi
sta_if.connect('Your_SSID', 'WiFi_Password')
# Check if connected
sta_if.isconnected()
# If connected check config 
sta_if.ifconfig() 

NOTE DOWN THE IP ADDRESS, WE WILL NEED IT LATER

Remember, just like python command line all code is erased on closing the console, same happens hereafter restart, but Wi-Fi and WebREPL configuration will stay.
So after a restart, it will automatically connect to your Wi-Fi.

If you type following code again

#Check if connected
sta_if.isconnected()
#If connected check config 
sta_if.ifconfig()

It will show this

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'sta_if' isn't defined

It means objects (or variables) are erased but the configuration like this is saved.

Enable WebREPL
import webrepl_setup

You will be prompted to enable or disable WebREPL and to set a password (REMEMBER THE PASSWORD). Like this

MicroPython Command Prompt in Arduino IDE Serial , Setting Up WebREPL
MicroPython Command Prompt in Arduino IDE Serial

So to solve this we will upload/modify python files on ESP8266. Let’s see how.

Check which files are currently in the device.

import os
os.listdir()
# Currently existing files will be printed like this
>>> ['boot.py']

boot.py is the main file and is executed first so we will edit this file.

Let’s upload files

But first

Download WebREPL Client From Here. This tool has GUI as well as CLI. We will be exploring GUI.

Open webrepl.html that is located in that folder.

MicroPython WebREPL
MicroPython WebREPL
  1. Enter your NodeMCU password and type REPL Password (input will not be shown) you configured earlier.
  2. In Get a file text box type boot.py, this will download boot.py file to your PC.
  3. Edit this file, Fading example below, add these lines at end of the file.

We will create blink function because it will block the command line till it’s execution.
However, it can be stopped by pressing CTRL+C (Just like in python) but Arduino IDE doesn’t support sending Key Combination (or signal) from the serial monitor.

You can use other software like Putty

from machine import Pin
import time # for delay function
#Create PWM object
led = Pin(2, Pin.OUT)              # Pin 2 (D4) is inbuilt LED
                                 # on ESP8266

def blink():
    i=0
    for x in range(5): # blink 10 times
        led.on()
        time.sleep_ms(200)
        led.off()
        time.sleep_ms(200)
blink()
  1. Then Upload file
    Upload file to MicroPython by WebREPL
  2. Restart by pressing the reset button.

To continue exploring more head over to MicroPython ESP8266 Documentation page by clicking here.

Conclusion

MicroPython is a great way to program NodeMCU, especially if you are a beginner in electronics and don’t know much.
However, python performance is very lower than C/C++, means Arduino language is faster than MicroPython.
Also, the community size of MicroPython is still lower than Arduino, so you may struggle to find libraries or solution to a bug if encountered.

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Aakash Kumar

This is Aakash Kumar, most of the time just gone in playing with those little modules. Most of them got burned, blasted and some got passed through my intestines. Interested in embedded systems, gaming, and electronics, pursuing B.Tech. in Electronics and Communication Engineering and still in a play.

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