DHT22 returning zeros

[jfedor]

Just another datapoint: Adafruit's library worked for my DHT22 with an Arduino Micro, but returned zeros with a 3.3V Trinket. ringerc's library works fine on the Trinket.

[jxlbbb]

I have the same problem

DHT22 returning 00 for temp and humidity.

I have tried the same sensor, same setting with Mega2560 using 3.3V and it work fine.
Definitely from the Fio. Maybe because of the 8Mhz clock ?

[jxlbbb]

In addition to my previous post, I confirm that with the library
https://github.com/ringerc/Arduino-DHT22
it works well.

In the DHT22.cpp file, there is a hardcoded limit at 2000 ms for calling the sequence.
if(currentTime - _lastReadTime < 2000)

I have relaxed this limit and search how far I could go without additional errors.
delay(400);
was the minimal interval between two calls.
As I intend to make a call every min for saving power, it should be OK.