Firmware

The firmware is written in async Rust (no_std) using esp-hal and a small set of supporting crates.

Prerequisites

To build and upload the firmware to your device, ensure you have the following installed:

• Rust
• The stable toolchain with the ESP32-C3 target architecture installed:

  rustup toolchain install stable --component rust-src --target riscv32imc-unknown-none-elf
  

• probe-rs, see installation instructions
  • OS notes:
    • Linux: set up udev rules for your debug probe or USB‑Serial device (see probe-rs udev guide).
    • Windows/macOS: ensure the correct USB drivers are installed and select the appropriate serial port in your tooling.

How to Build the Firmware

To build the firmware, run:

cargo build --release

This compiles the firmware only. To build and flash the device, see Build and Flash your Device.

How to Flash Your Crimpdeq

Erase Device Memory

If this board was previously used for other projects, erase its flash once:

probe-rs erase

⚠️ Note: Erasing is only needed once. Avoid erasing routinely, or you will lose your calibration values.

Build and Flash Your Device

With a custom runner configured in .cargo/config.toml, you can build, flash, and open a serial monitor with:

cargo run --release

This opens a serial monitor, allowing you to view log messages in real time.

To modify the log level, update the DEFMT_LOG value in .cargo/config.toml or set it when running the command:

DEFMT_LOG=debug cargo run --release

⚠️ Note: If your DevKit does not include USB‑Serial‑JTAG, flash via UART by updating the custom runner in .cargo/config.toml to use espflash instead of probe-rs.

Configuring Environment Variables

If you need to change DEVICE_ID, DEVICE_NAME, or DEVICE_VERSION_NUMBER, update their values in .cargo/config.toml.

After making changes, rebuild and flash the device for the new values to take effect.

Code Structure

hx711

This module implements the load cell functionality. It’s an async version of the loadcell crate with additional modifications.

ble

This module implements the Bluetooth Low Energy (BLE) functionality:

• Defines the GATT server and services
• Handles advertising and connections
• Defines the Progressor service with data point and control point characteristics

progressor

The progressor module implements the Tindeq API, enabling BLE (Bluetooth Low Energy) communication between the ESP32-C3 and a smartphone.

Main Tasks

The main.rs file defines several asynchronous tasks that run concurrently:

• measurement_task:
  • Initializes the load cell.
  • Handles taring and reads measurements from the sensor.
• ble_task:
  • Long‑running background task required alongside other BLE tasks.
• gatt_events_task:
  • Processes GATT events such as control‑point writes.
• data_processing_task:
  • Handles sending notifications with data points.
• battery_voltage_task:
  • Periodically reads the battery voltage.
• deep_sleep_task:
  • Monitors inactivity; after a timeout, the device enters deep sleep.

Communication between tasks occurs via a Channel.