bme680-driver

Table of Contents

• Overview
• Features
• Repository Structure
• Installation
• Quick Start
• Units & Precision
• License

Overview

A type-safe, no_std Rust driver for the Bosch BME680 environmental sensor. It provides high-level access to temperature, humidity, atmospheric pressure, and gas resistance measurements using the embedded-hal traits.

Features

• Power Saving: Individually enable/disable gas, pressure, temperature, or humidity measurements to reduce power consumption.
• Typestate Pattern: Prevents illegal sensor states and ensures correct initialization.
• Fixed-Point Arithmetic: High-performance compensation formulas without the need for a floating-point unit (FPU).
• Type-Safe Units: Uses custom types like Celsius and Milliseconds to prevent unit-mixing errors.
• No-Std: Suitable for all bare-metal microcontrollers (STM32, ESP32, AVR, etc.).

Repository Structure

└── bme680-driver/

    ├── src/

    │   ├── lib.rs

    │   └── calc.rs

    ├── examples/

    │   └── stm32f407.rs

    ├── .cargo/

    │   └── config.toml

    └── Cargo.toml

Installation

Add this to your Cargo.toml:

[dependencies]

bme680-driver = "0.2.0"

Quick Start (STM32 Example)

use bme680_driver::*;

// Initialize I2C and Delay from your HAL...
// let i2c = ...
// let mut delay = ...

let bme = Bme680::new(i2c, 0x76);
let mut bme = bme.init(&mut delay).expect("Failed to init BME680");

let mut config = Config {
    osrs_config: OversamplingConfig {
        temp_osrs: Oversampling::X2,
        hum_osrs: Oversampling::X1,
        // Example: Disable pressure measurement to save power and time
        pres_osrs: Oversampling::Skipped,
    },
    iir_filter: IIRFilter::IIR0,
    // Enable gas measurement by providing a profile (wrap in Some)
    gas_profile: Some(GasProfile {
        index: GasProfileIndex::Profile0,
        target_temp: Celsius(300),
        wait_time: Milliseconds(300),
    }),
    ambient_temp: Celsius(2300), // 23.00 °C initial guess
};

bme.configure_sensor(&mut config).unwrap();

loop {
    // Perform measurement (waits automatically for heating if enabled)
    let data = bme.read_new_data(&mut delay).unwrap();
    
    // Use helper methods to format data (no floats needed!)
    let (temp_whole, temp_frac) = data.temp.split();
    let (hum_whole, hum_frac) = data.hum.split();
    
    // Log formatted data (e.g., via defmt)
    defmt::println!("Temperature:    {}.{} °C", temp_whole, temp_frac);
    defmt::println!("Humidity:       {}.{} %", hum_whole, hum_frac);
    defmt::println!("Gas Resistance: {}  Ohm", data.gas.0);
    
    // Pressure was skipped, so it returns default/zero values
    // defmt::println!("Pressure: Skipped"); 
    
    defmt::println!("");
    
    // Dynamically update heater profile with current ambient temperature.
    // We only do this if gas measurement is actually enabled.
    if let Some(profile) = config.gas_profile {
        // We access the raw value (.0) to wrap it into Celsius
        bme.set_gas_heater_profile(profile, Celsius(data.temp.0)).unwrap();
    }
    
    delay.delay_ms(5000);
}

Units and Precision

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.