A Mongoose library for Sensirion's SHT31 integrated circuit.

SHT3x-DIS is the next generation of Sensirion’s temperature and humidity sensors. It builds on a new CMOSens sensor chip that is at the heart of Sensirion’s new humidity and temperature platform. The SHT3x-DIS has increased intelligence, reliability and improved accuracy specifications compared to its predecessor. Its functionality includes enhanced signal processing, two distinctive and user selectable I2C addresses and communication speeds of up to 1 MHz. The DFN package has a footprint of 2.5 x 2.5 mm while keeping a height of 0.9 mm. This allows for integration of the SHT3x-DIS into a great variety of applications.

Additionally, the wide supply voltage range of 2.4 to 5.5 V guarantees compatibility with diverse assembly situations. All in all, the SHT3x-DIS incorporates 15 years of knowledge of Sensirion, the leader in the humidity sensor industry.

See datasheet for implementation details.

A great place to buy a ready made and tested unit is at Adafruit.

An example program using a timer to read data from the sensor every 5 seconds:

#include "mgos.h"
#include "mgos_i2c.h"
#include "mgos_sht31.h"

static struct mgos_sht31 *s_sht31;

static void timer_cb(void *user_data) {
  float temperature, humidity;

  temperature=mgos_sht31_getTemperature(s_sht31);
  humidity=mgos_sht31_getHumidity(s_sht31);

  LOG(LL_INFO, ("sht31 temperature=%.2f humidity=%.2f", temperature, humidity));

  (void) user_data;
}

enum mgos_app_init_result mgos_app_init(void) {
  struct mgos_i2c *i2c;

  i2c=mgos_i2c_get_global();
  if (!i2c) {
    LOG(LL_ERROR, ("I2C bus missing, set i2c.enable=true in mos.yml"));
  } else {
    s_sht31=mgos_sht31_create(i2c, 0x44); // Default I2C address
    if (s_sht31) {
      mgos_set_timer(5000, true, timer_cb, NULL);
    } else {
      LOG(LL_ERROR, ("Could not initialize sensor"));
    }
  }
  return MGOS_APP_INIT_SUCCESS;
}

This project is not an official Google project. It is not supported by Google and Google specifically disclaims all warranties as to its quality, merchantability, or fitness for a particular purpose.