I have 5 DHT22 sensors that lockup at 71.6 after about 36 hours of use. They are powered by the 5v from my Arduino 256Mega. I can get them to work again if I power them down for a few seconds. They were about $5 apiece so they weren't the cheapest out there. Is this a known issue with them or do I have some duds?
How do you know that the sensors are the problem? Is the Arduino showing other signs of life when they fail?
I have several ds18 temp sensors and they are working fine. Is there a way to connect to the monitor over a network connection?
Hi,
Can I suggest you look up the "Blink without delay" example and include it in your code to blink the on board LED.
This is called a heartbeat LED, and will indicate if your code has stopped or it is still running and the problem occurs.
Tom... 
The Arduino appears to be working. It is responding to commands from a Hubitat to turn on relays as determined by the temps from the DS18 sensors.
What happens if you write a simple program that just gets the data from one DHT22 repeatedly and echoes it to Serial?
Since the Arduino is running some heating and garage door operations and the fact that they seem to take quite some time to fail I don't think it would be wise for me to only run a script for them. I have thought about rigging a relay on a timer to cut power to them every so often to get them back on track.