The DHT22 is a good choice for adding temperature and humidity to your home automation system. I was forced to add this device after experiencing a bad mold condition in our Munich apartment. The sensor is helpful to show when high humidity conditions exist.
The device looks like this and there are many blog posts for connecting it with an ESP8266.
Here are the troubleshooting steps I went through to get it working on a breadboard and received no reading on the data pin.
- Tried many different GPIO pins GPIO16 caused LED to come on, switched to GPIO14 D5 and GPIO13 D7.- Tried 2nd sensor with no change. - Hardware setup - GPIO14 set to default, also tried input (its one wire, so must read and write).- Pullup is 4.7k - 3.3V, currently powering 1-wire DS18b20 - too much to power 2 devices? Lets try with 1-wire unplugged. (update - did not work).- Change 4.7k to 10k; did not work.- GPIO15-D8, GPIO12-D6 FAIL
THE BREAD BOARD WAS THE PROBLEM! Power rails are not connected all the way across the board. Moved DHT22 next to ESP8266 and readings first time. Current setup GPIO14 with 10k pullup and 5v from Vin.
