Si7021-T-RH  

A Rust crate for Silicon Labs Si70xx series sensor (7013, 7020, 7021)

https://github.com/marvinrobot42/si7021-t-rh.git

The Si7013, 7020, 7021 sensor relative humidity and temperature sensor with I2C interface.

All I2C API functions are implemented.

Features

• uses embedded-hal version 1.0.x
• designed for embedded use (ESP32-C3, -C6 and -S3 and Raspberry Pi)
• ESP32 RISC V and Raspberry Pi examples included
• enable/disable builtin heater for clearing condensation or frost (when not reading temperature)
• configurable heater power level
• reads device model number, serial numbers and firmware version
• an easy to use Measurements struct
• no_std embedded compatible

Notes

Developed using Adafruit Si7021 STEMMA QT (QWIIC) model: https://www.adafruit.com/product/3251

Recent version history

• 0.1.3 Updated README.md
• 0.1.2 Fixed repo name (whoops it is s17021-t-rh instead of si7021)
• 0.1.1 Fixed README.md
• 0.1.0 Initial release

Usage

Add the dependency to Cargo.toml.

[dependencies.si7021-t-rh]
version = "0.1"

1. Create a hardward specific I²C driver interface and delay function
2. Create an Si7021 struct with the I²C interface and a delay function as parameters.
3. Initialize the Si7021 instance 4.a Read relative humidity 4.b Read temperature or
4. Call read_measurements() fn which return both relative humdity and temperature faster than call the seperate methods due to Si70xx "Read Temperature Value from Previous RH Measurement function"

Simple Example

A more complete example is in the repository examples path

use anyhow::Result;  // add dependency for this
use si7021_t_rh::Si7021;
use log::{info, error};

...


fn main() -> Result<()> {

  ...as per your hardware hal, below is ESP32-C3 - C6 style

  let peripherals = Peripherals::take().unwrap();
  let pins = peripherals.pins;
  let sda = pins.gpio6; // esp32-c3  has pins.gpio0 , check your board schematic
  let scl = pins.gpio7; // esp32-c3  haspins.gpio1, check your board schematic
  let i2c = peripherals.i2c0;
  let config = I2cConfig::new().baudrate(400.kHz().into());
  let i2c_bus = I2cDriver::new(i2c, sda, scl, &config)?;

  let mut delay: Delay = Default::default();   // your hardware delay from use ...
  let mut my_si7021 = Si7021::new(i2c_bus, delay);
  my_si7021.init_device().unwrap();
  FreeRtos::delay_ms(250);  // or your sleep function here

  loop {
    // the read_measurements() method is a little faster (-30 msec) than reading humidity and temperature separately
    log::info!("Si70xx measurements are {:#?}", my_si7021.read_measurements().unwrap());
    FreeRtos::delay_ms(10000);
  }

}
    

License

You are free to copy, modify, and distribute this application with attribution under the terms of either

• Apache License, Version 2.0 (LICENSE-Apache-2.0 or https://opensource.org/licenses/Apache-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

This project is not affiliated with nor endorsed in any way by Silicon Labs or Adafruit.