Adafruit temperature and humidity sensor breakout board htu21d f adafruit 1899 the b htu21d f b is an i sup2 c digital temperature and humidity sensor with high accuracy and an operating range that is optimised from 5 to 95 rh and from 30 c to 90 c the breakout board includes a ptfe filter to keep the sensor clean a 3 3v regulator and i sup 2c level shifting circuitry this allows the board to be used safely with any kind of microcontroller with 3 3 to 5v power or logic br br