:PROPERTIES:
:ID:       6cd321bb-34bf-4a93-96f6-a9ef93257bd1
:END:
#+title: MicroPython
A pared down version of [[id:cda9c620-fec5-4549-b979-22fc06819d77][Python]] designed for programming [[id:c412e81c-9271-4224-89b7-315a4b89968e][Microcontrollers]] like
the [[id:d97fde4a-0e91-40f9-ac57-d0cd67295d14][ESP8266]].

* REPL
The [[https://docs.micropython.org/en/latest/reference/repl.html][MicroPython REPL]] is available through a device's serial interface. It
functions in two modes:

- Friendly :: A user-friendly REPL with indentation and tab completion.
  Evaluation is echoed back. Indentation may be temporarily disabled toggling
  "paste mode" with =Ctrl+E=. Execution may be interrupted with =Ctrl+C=.
- Raw :: A machine-friendly REPL for tools to provide raw code to be executed.
  Essentially functions similar to the friendly REPL in paste mode, without
  output echoing. /Note: Automatic startup/soft-reset execution of =main.py= is
  disabled while the REPL is in raw mode./
* Documentation
- [[https://docs.micropython.org/en/latest/index.html][Official documentation]]

* Tools
- [[https://docs.micropython.org/en/latest/reference/mpremote.html#][mpremote]] :: MicroPython remote control. Provides REPL access, editing, and
  file system mounting.
* Questions
** What files does the MicroPython firmware expect to find?
- =boot.py= :: Performs initialization when the device is powered up.
- =main.py= :: If present (and no errors occurred while executing =boot.py=), it
  is executed after =boot.py= and functions as an application code entry point.
  /Execution of this file is skipped if the REPL is not in "friendly" mode, e.g.
  if a tool has switched to the "raw" REPL./

The =mpremote= tool uses the raw REPL to execute its commands, including
performing a soft reset. Therefore, it is advisable to keep application code
(particularly application loops) in =main.py= rather than =boot.py= so that
=mpremote= commands aren't blocked by running application code. This way,
application code is only executed when requested explicitly while developing,
but will still execute automatically during a normal device boot.