ESP8266 Community Forum

- Mon Mar 02, 2015 1:56 pm #11114 Hi!

I'm also getting noise in my DHT22 readings. It was really bad when I powered the sensor and the esp from the same LD33V regulator. Now I'm using a separate regulator for the sensor and it looks like a bit better but still not so good.

- Mon Mar 02, 2015 2:10 pm #11115 Just thinking out loud here, but did any of you try to run the sensor on 5V? Maybe the quality will improve then?

http://elinux.org/RPi_GPIO_Interface_Ci ... el_shifter

- Mon Mar 02, 2015 4:48 pm #11124 I just tried to put further away the sensor from the esp and now it works much better.

- Tue Mar 03, 2015 4:01 am #11146 google found this DHT22 wiki: electrodragon.com

With 3.3V voltage supply cable length shall not be more than 30cm.

Each read out the temperature and humidity values ​​are the result of the last measurement, For the real-time data, sequential read twice, Recommended repeatedly reads the sensor and each read sensor interval is greater than 2 seconds to obtain accurate data.

I think roughly translates to: "read the sensor twice with at least 2 sec interval, keep the last value".

Edit: I just did a simple test where i continously sampled the DHT22 after i connected it. It takes about 10 samples before the humidity is stable
(and it's not just my sweaty palms that caused it )