Humidity Sensor¶

Sensirion SHT40-AD1B-R2 Humidity & Temperature sensor

Datasheets

SHT40-AD1B-R2 Datasheet

Description¶

SHT4x is a digital sensor platform for measuring relative humidity and temperature at different accuracy classes. The power-trimmed internal heater can be used at three heating levels thus enabling sensor operation in demanding environments.

Relative humidity accuracy: up to ±1.5 %RH
Temperature accuracy: up to ±0.1 °C

Note

The temperature value is the one from the chip, not the environment. It can be used to monitor the sensor temperature when using the heater.

Warning

The heater is designed for a maximal duty cycle of less than 5% when it is periodically heated. Otherwise the sensor might be destroyed.

Usage¶

The sensor will be initialized through the BSP. These default settings are high precision measurements. A measurement takes about 10ms.

// Read the humidity
float humidity = yggdrasil_HumiditySensor_GetHumidity(HumiditySensorPrecision_High);
printf("Humidity: %f%%RH \n", humidity);

// Read the humidity
auto humidity = bsp::ygg::prph::HumiditySensor::getHumidity();
printf("Humidity: %f%%RH \n", humidity);

// Read the temperature of the sensor
float temp = yggdrasil_HumiditySensor_GetTemperature(HumiditySensorPrecision_High);
printf("Temperature: %fC \n", temp);

// Read the temperature of the sensor
auto temp = bsp::ygg::prph::HumiditySensor::getTemperature();
printf("Temperature: %fC \n", temp);