Electron DHT22 Not Reading Temperature


#1

I have set up 4 Electrons which read the temperature and humidity using a DHT22
I send this to ThingSpeak
One of the Electrons is not reading the temperature and humidity is giving 6553.5. I was thinking it is a bad DHT22 but I changed the sensor twice. If I disconnect the sensor humidity reads zero. I reconnect and it goes back to 6553.5 and still no temperature reading.
Does this point to something? Could I have a bad Electron?
I am using the Adafruit_DHT as in all my other ones.
Thanks


#2

If the sensor works on another electron with the same code and power supply - then I would assume the electron is faulty. Do make sure the DeviceOS is the same version. Then inspect the electron closely around the pin and see if there is perhaps a manufacturing fault like a solder spider or bad connection.


#3

I will try changing sensor to known good Particle. Also known power supply. If on battery however does Electron get battery from power supply or battery which stabilizes voltage?
Thanks.


#4

Testing on a fully charged battery is good and will isolate a bad power supply - although the DHT does not take much power. It would be helpful to post a picture / diagram of how they are connected to the electron


#5

Just to make sure you know: When powered via the battery only there will be no voltage on Vin, so you won’t be able to power anything off of Vin in this case.

And when powering via USB with LiPo attached the core will be powered from both sides as needed. Continuos demand will most likely be satisfied off of USB while also charging the LiPo but sudden demands (e.g. by the cellular modem) will draw from USB and LiPo concurrently.


#6

Thanks. I am pulling on D1,D2,D4. I just checked ThinkSpeak. Earlier I had taken the possibly broken DHT22 and put on Electron I know was sending correctly and that works. So it is looking like it is bad board. I will switch power supplies to close that one out but it sounds like with with LiPo attached that should not be the problem.
Thanks for everyone’s help.