MicroPython.js

MicroPython transmuted into Javascript (WASM) by Emscripten.

Official Repo https://github.com/micropython/micropython/tree/master/ports/javascript

Testing and Contribution Needed, feel free to make an issue or even better, a PR

What's New on 1.1

• New Async/Await or Promise API
• New Python classes to expose JS API and Objects like DOM API, XHR, Node.JS require, and etc

Running with Node.js

On Node.JS console

const mp_js = require('micropython');

mp_js.init(64 * 1024);
mp_js.do_str("print('hello world')\n");

On production/actual code use AsyncFunction or Promise to get the guaranteed result

(async () => { //AsyncFunction
  const mp_js = await require('micropython');

  mp_js.init(64 * 1024);
  await mp_js.do_str("variable1 = {'data1': 1}");
  await mp_js.do_str("variable1.get('data1')"); //Access variables from the previous event loop
})();

Running with Webpack

Running MicroPython on Webpack is a little bit tricky. It expects the firmware.wasm file at /static/js/firmware.wasm. So a simple solution is to make static and js folder on webpack's public directory and put firmware.wasm on it. (PR is accepted for a better solution)

mkdir -p public/static/js
cp node_modules/micropython/lib/firmware.wasm public/static/js

And import it on your Javascript file

import mp_js from 'micropython';

(async () => {
  await mp_js;
  mp_js.init(64 * 1024);
  mp_js.do_str("print('hello world')\n");
})();

API

The following functions have been exposed to javascript.

init(stack_size)

Initialize MicroPython with the given stack size in bytes. This must be called before attempting to interact with MicroPython.

do_str(code)

Execute the input code. code must be a string. Returns a promise resulting an stdout.

init_repl()

Initialize MicroPython repl. Must be called before entering characters into the repl.

process_char(char)

Input character into MicroPython repl. char must be of type number. This will execute MicroPython code when necessary.

init_python(stack_size)

NEW!! This function execute js.py to expose JS API to Python, even some helper function and experimental asynchronous queue/stack logic. Example:

mp_js = require('micropython');

(async () => {
  await mp_js;
  await mp_js.init_python(64 * 1024);
  await mp_js.do_str(`

  import js

  #This function executes every line but exit the event loop if wait function is called and resumes after it resolve
  exec("""

  fetch = False
  if isbrowser:
     fetch = JS('fetch')
  else:
     require = JS('require')
     fetch = require('node-fetch')
  response = fetch('https://github.com')
  response = wait(response)
  result = response.text()
  result = wait(result)
  print(result)

  """)
  `);
})();