smolOS

Specialized Microcontroller-Oriented Lightweight Operating System

smolOS is a tiny (<20KB, <500LOC) and simple 🧪 research ⚙️ operating system ⌨️ written in 🐍 MicroPython for microcontrollers giving user a POSIX-like 📁 environment to play. It came with a set of 🧰 tools and 🪄 demos.

System should run on any MicroPython supproted board but it's tested and developed on Seeed XIAO RP2040,

Official homepage:

• smol.p1x.in/os/ (http)
• smol.p1x.in/os/ (https)

Real Life Usecases

• listing and removing unwanted files on board
• checking free space
• easy way to write simple programs and run them from the OS
• quicly iterating parameters for a program
• editing small bugs in programs
• having fun with microcontrollers

smolOS Features

• Changes microcontroller into a small working PC
• Homemade for fun and learning
• Super small and fast
• Easy to use, simillar to MS-DOS, POSIX-like environments
• List and manipulates files
• Text editor included (very basic but capable)
• Basic tools and demos included (for NeoPixels, Buzzers, LEDs)
• Build on MicroPython with clear code
• Stability and simplicity are the main principle behind the code
• Free and open :)

Additoinal Programs

• ansi - Displays ANSI escape codes
• life - Game of Life implementation for smolOS (text)
• buzz - Simple synthezator for 1-bit music (requies a buzzer)
• bytebeat - Implementation of ByteBeat for a buzzer

All of those are for NeoPixel Grid 5x5 BFF:

• duck - Yellow Rubber Duck for programmers
• neolife - Game of Life implementation
• pixel - Tools for playing with one LED
• plasma - Demoscene plasma effect
• font - Font bitmaps (for scroller)
• scroller - Scrolls text

Installation

Super Quick Quide

• put main system file smolos.py onto the board flash (that has latest MicroPython firmware)
• (optional) for auto-boot copy main.py too
• restart device

Detailed Guides

• XIAO RP2040 Guide
• ESP8266 Guide

Connecting

As normal user:

$ picocom /dev/ttyACM0

Press ctrl+a+x to exit.

Running

First start. Or after flashing new main.py file. Restart the microcontroller:

>>> machine.soft_reset()

Autoboot

This should restart the device and "boot" you into the smolOS. Like so:

Manual

If you put smolos.py then you need to boot the system by hand. In MicroPython REPL write:

>>> from smolos import smolOS
>>> os = smolOS()
>>> os.boot()

Using

Write help for manual :)

Intresting forks

• smolOS by rbenrax - very nice, goes as close to the POSIX as you can get!
• pegasusOS by 047pegasus - adds easy networking

Missing Features / ROADMAP

Some kind of a roadmap (from high to low priority)

• os: move/copy files
• (external, threaded programs) check exception for used core instead of class variable
• good manual

Articles

• hackster.io
• cnx-software.com
• lobste.rs