4John316 asked 6 years ago
On the ESP8266 course, I have followed the example and schematic. I currently have only the DHT22 sensor on the breadboard. The sensor worked about 3 times originally. I have tried reinstalling and re-positioning all the components about 10 times. This included trying 4 different DHT22 sensors. The CommPort reads “Failed to read from DHT sensor!”
Do you know what I should try next ?
Rui Santos Staff answered 6 years ago
Hello, how are you powering the ESP8266? Can you power it with a different power source that can provide more current (different than your computer USB port)?
How much voltage are you feeding the DHT with 3.3V or 5V?
Thanks!
4John316 answered 6 years ago
Rui
Thanks for the response.
I have been powering the ESP8266 with the USB (it worked originally). Now I cannot get the DHT22 to read.
I have tried powering the two separately with 5 volts and 3.3 volts and then 3.3 volts and 5 volts. I have tried a new DHT22 (this is the 5th one). I have tried every combination to no avail.
The odd thing is, it worked originally for about 3 refreshes.
I have a new ESP8266 on order.
Do you have any suggestions ?
Thanks
Rui Santos Staff answered 6 years ago
I don’t think it’s a problem with your ESP or DHT. I think it’s a problem with power.
Can you power the DHT with 5V from your ESP, but power your ESP with a bench power supply or old phone charger?
Then, go to the ESP IP address and load the web server to see if it’s displaying the DHT readings… Some USB ports don’t supply enough current to power the DHT reliably.
Note: also double-check all the connections with your DHT and ESP (don’t have any loose wires).
When the DHT11/DHT22 failed to read from DHT sensor doesn’t work, it’s usually:
- Power issue
- Wrong wiring
- Faulty DHT
- Faulty ESP8266
Please read our DHT11/DHT22 Troubleshooting Guide.
Thanks for your patience.