pico-htu21d

This is a MicroPython library for the Raspberry Pi Pico and the HTU21D Digital Relative Humidity sensor with Temperature output.

Example

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.

Customizing configuration

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)