This is a MicroPython library for the Raspberry Pi Pico and the HTU21D Digital Relative Humidity sensor with Temperature output.
from machine import Pin, I2C
from utime import sleep
from htu21d import HTU21D
i2c0_sda = Pin(8)
i2c0_scl = Pin(9)
i2c0 = I2C(0, sda=i2c0_sda, scl=i2c0_scl)
htu21d = HTU21D(0x40, i2c0)
while True:
measurements = htu21d.measurements
print(f"Temperature: {measurements['t']} °C, humidity: {measurements['h']} %RH")
sleep(1)measurements is a dictionary that contains the following values:
| Field | Description |
|---|---|
| t | The temperature (°C) |
| t_dew_point | The temperature at which the water vapor in the air becomes saturated and condensation begins |
| t_crc_ok | The result of the Cyclic Redundancy Check of the temperature (True, False or None if disabled) |
| t_adc | The 'raw' temperature value as produced by the sensor |
| h | The relative humidity (%RH) |
| h_crc_ok | The result of the Cyclic Redundancy Check of the humidity (True, False or None if disabled) |
| h_adc | The 'raw' humidity value as produced by the sensor |
This is the circuit for the example code above. It uses the GY-21 HTU21 breakout board.
The default settings use a 12 bits resolution for the relative humidity and a 14 bits resolution for the temperature. The heater is disabled and the measurements include the CRC results.
The next example uses a customized configuration:
from htu21d import HTU21D, HTU21DConfiguration
config = HTU21DConfiguration()
config.measurement_resolution = HTU21DConfiguration.RH_8_T_12_BIT
config.heater_enabled = True
config.crc_enabled = False
htu21d = HTU21D(0x40, i2c0, config)