# Pico Environment Sensor

This firmware, written in Rust using [embassy-rs](https://github.com/embassy-rs/embassy), is designed for the [Raspberry Pi Pico 2 W](https://www.raspberrypi.com/documentation/microcontrollers/pico-series.html#pico2w-technical-specification) platform using the RP2350 microcontroller. Its application is an environment-sensing device which can measure CO2 concentration in the atmosphere, ambient temperature and humidity. 

## 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](./scripts/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`)