This firmware, written in Rust using embassy-rs, is designed for the Raspberry Pi Pico 2 W platform using the RP2350 microcontroller. Its application is an environment-sensing device which can measure CO2 concentration in the atmosphere, ambient temperature and humidity.

The effects of increased CO2 concentration on cognitive function become increasingly pronounced at CO2 concentrations exceeding 1000 ppm. There's a fantastic YouTube video by Kurtis Baute and Tom Scott which you can watch for a short summary. Open your window right now!

Building

Prerequisites

Rust compiler & cargo package manager: https://www.rust-lang.org/
RPi Pico SDK: https://github.com/raspberrypi/pico-sdk
RPi picotool: https://github.com/raspberrypi/picotool
ARM bare metal compiler toolchain
- arm-none-eabi-gcc (& arm-none-eabi-newlib) on Arch Linux, your system may have different package names
The ARMv8 or RISC-V Rust toolchain:
- ARMv8: rustup target add thumbv8m.main-none-eabihf
- RISC-V: rustup target add riscv32imac-unknown-none-elf

Environment configuration

This build system assumes the environment variables: PICO_BOARD, PICO_PLATFORM & PICO_SDK_PATH are set. picotool should also be available in the PATH.

The env-vars.sh script sets these values to pico2_w, rp2350-arm-s and my personal Pico SDK path, respectively. The environment variable definitions in this file can be set with source ./scripts/env-vars.sh.

Compiling & running

cargo build (or cargo build --release)

If you wish to run the binary on your Pico (connected in BOOTSEL mode):

cargo run (or cargo run --release)