Sense temperature and humidity from a single device. This through hole component will sense 0-100% Relative Humidity and temperatures ranging from 04- to 80 degrees Celsius
This device accepts DC voltages range of 3.3v to 5.5v. There is only a single data pin so connection and MCU requirements are minimal. The other pins are VDD for power in and two GND pins.
The data pin communicates its current condition (humidity and temperature) using a streat of 1s and 0s (high/low). The stream of 1s and 0s will form a binary number. The first 16 bits will represent first the RH (Relative humidity) and the second 16 bits will represent the temperature. There is a remaining 8 bits that will serve as the checksum (to make sure the data is correct).
First, the MCU sends a signal to the sensor which is just pulling the data line low (for about 1 to 10 ms so the sensor has time to catch this event) and then high again. Then the sensor will then pull the line low and then high again to signal that the start signal has been heard. Then the sensor will send out the data to the MCU.