bme280.rs

//! This example reads the chip ID from a Bosch BME280.
//!
//! The hardware for this example can be purchased from adafruit:
//!
//! * https://www.adafruit.com/product/2264
//! * https://www.adafruit.com/product/2652
//! * https://www.adafruit.com/product/4399
//! * https://www.adafruit.com/product/4472

use eh0::blocking::i2c::WriteRead;
use eh1::i2c::I2c;
use ftdi_embedded_hal as hal;

fn main() {
    cfg_if::cfg_if! {
        if #[cfg(feature = "ftdi")] {
            let device = ftdi::find_by_vid_pid(0x0403, 0x6014)
            .interface(ftdi::Interface::A)
            .open()
            .unwrap();
        } else if #[cfg(feature = "libftd2xx")] {
            let device: libftd2xx::Ft232h = libftd2xx::Ftdi::new().unwrap().try_into().unwrap();
        } else {
            compile_error!("one of features 'ftdi' and 'libftd2xx' shall be enabled");
        }
    }

    let hal = hal::FtHal::init_default(device).unwrap();
    let mut i2c = hal.i2c().unwrap();

    // ID register is constant
    const BME280_CHIP_ID: u8 = 0x60;

    let mut buf: [u8; 1] = [0];
    const BME280_ADDR: u8 = 0b1110111;
    const BME280_CHIP_ID_ADDR: u8 = 0xD0;

    println!("Reading chip ID from BME280 with embedded-hal v0.2");
    WriteRead::write_read(&mut i2c, BME280_ADDR, &[BME280_CHIP_ID_ADDR], &mut buf)
        .expect("Failed to read from BME280");
    assert_eq!(buf[0], BME280_CHIP_ID);
    println!("Chip ID ok from embedded-hal v0.2");

    println!("Reading chip ID from BME280 with embedded-hal v1");
    I2c::write_read(&mut i2c, BME280_ADDR, &[BME280_CHIP_ID_ADDR], &mut buf)
        .expect("Failed to read from BME280");
    assert_eq!(buf[0], BME280_CHIP_ID);
    println!("Chip ID ok from embedded-hal v1");
}