Crate embedded_qmp6988 

embedded-qmp6988

This is a platform agnostic Rust driver the QMP6988 digital barometric pressure sensor using the embedded-hal traits.

The device

The QMP6988 sensors is high accuracy and small size barometric pressure sensor with low current consumption.

It can be addressed through an I²C or an SPI interface. This driver uses the I²C interface.

Documentation:

• Datasheet
• C++ driver example

Features

• Choose the oversampling setting used for measurements.
• Choose the IIR filter used to reduce the noise in the measurements.
• Perform a single measurement (using the force power mode).
• Do a sofware set.
• Perform repeated measurements using the normal power mode.
• Include a no floating-point variant for systems without fpu.

Usage

To use this driver, import what you need from this crate and an embedded-hal implentation, then instatiate the device.

use embedded_qmp6988::{IirFilter, OverSamplingSetting, Qmp6988, DEFAULT_I2C_ADDRESS};
use linux_embedded_hal as hal;

fn main() -> Result<(), embedded_qmp6988::Error<hal::I2CError>> {
    // Create the I2C device from the chosen embedded-hal implementation,
    // in this case linux-embedded-hal
    let i2c = match hal::I2cdev::new("/dev/i2c-1") {
        Err(err) => {
            eprintln!("Could not create I2C device: {}", err);
            std::process::exit(1);
        }
        Ok(i2c) => i2c,
    };

    // Create the sensor and configure its repeatability
    let mut sensor = Qmp6988::new(i2c, DEFAULT_I2C_ADDRESS, hal::Delay {})?;
    sensor.set_filter(IirFilter::Off)?;
    sensor.set_oversampling_setting(OverSamplingSetting::HighSpeed)?;

    // Perform a barometric pressure measurement
    let measurement = sensor.measure()?;
    println!("Pressure: {:.2} hPa", measurement.pressure);
    Ok(())
}

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.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Structs

Measurement

The result of a measurement.

Qmp6988

QMP6988 device driver

Enums

Error

All possible errors generated when using the Qmp6988 struct

IirFilter

IIR (Infinite Impulse Response) filter.

OverSamplingSetting

The oversampling setting.

Constants

DEFAULT_I2C_ADDRESS

The default I2C address (SDO pin connected to low)

I2C_ADDRESS_LOGIC_HIGH

The I2C address when the SDO pin is connected to logic high

I2C_ADDRESS_LOGIC_LOW

The I2C address when the SDO pin is connected to logic low

Functions

calculate_altitude

Calculate the altitude (in m) from a measurement.