Micropython (ESP8622) By Example

MicroPython is a lean and efficient implementation of the Python 3 programming language that includes a small subset of the Python standard library and is optimised to run on microcontrollers and in constrained environments.

Prerequisites

Install Drivers and Identify COM port

Install the official nodemcu-devkit drivers for your OS.

Flashing the ESP8266 MCU

Firstly, erase the flash memory on the MCU. Memory is typically limited to a few megabytes.

esptool --port COM3 -c esp8266 --baud 460800 erase_flash

Write the firmware to the devices flash storage

esptool --port COM3 -c esp8266 --baud 460800 write_flash --flash_size=detect 0 esp8266-20180511-v1.9.4.bin

Connect to ESP8266 via Putty

Create a serial connection on your COM port with the correct baud rate:

Serial Line: COM3
Speed: 115200

A successful connection will yield a python REPL

MicroPython REPL

Run the following in the REPL to evaluate the device is working correctly:

from machine import Pin

# GPIO16 (D0) is the internal LED for NodeMCU
led_red = Pin(16, Pin.OUT)
# SETS the pin state to HIGH
led_blue.value(0)
# SETS the pin state to LOW
led_blue.value(1)

Copying files to the Flash Storage

To use ampy directly, you will need to run pipenv install and pipenv shell.

List all files within flash storage:

ampy -d 0.5 -p COM3 ls

Read the contents of a file from flash storage:

ampy -d 0.5 -p COM3 get boot.py

Copy file to flash storage at the root directory:

ampy -d 0.5 -p COM3 put examples/blink.py

Remove file from flash storage:

ampy -d 0.5 -p COM3 rm blink.py

Running a program on device boot

boot.py will run as a precursor to main.py. Creating a main.py will run every time the device is powered on.

touch main.py
# add contents to main.py
ampy -d 0.5 -p COM3 put main.py

Development

Select your favorite IDE or editor for Python and develop your project. Once you are ready to run the code on a ESP8266, you can use uPyCraft to easily copy across the files to the device and open a REPL.

Resources

Maintainer

If you want to contact me, check out my twitter account, find me on #apoclyps.