ESP 8266 Thing Dev Board appears to randomly stops transmitting

My Sparkfun ESP8266 Thing Dev board appears to randomly stop transmitting Datagrams. The board is connected to temperature and humidity sensors via I2C and programmed to send Datagrams containing measured data every 1 minute. I’ve had it running for over a year; it works fine for a while and then appears to stop transmitting. Recycling power restores normal operation. The Reset pin is connected to power via an internal resister, so a floating Reset should not be the problem. Any ideas?

That definitely sounds like a software issue. Hard part is that the list of possible reasons makes it hard to narrow down. I would suggest that you should purchase a new one and upload with the same code. If something breaks in the same way, then you could say that it was a hardware failure.

Thanks for the response. I did read online that the ESP8266 has a hardware watchdog that by default is enabled. That would suggest that even with a software problem, it should automatically reset which in not what I’m seeing. Good suggestion - I’ll try another board. This should eliminate (ideally) board and wiring problems. Again thanks for responding.

I’ve had a few times when my ESP8266 has had problems talking to an I2C sensor – the I2C sensor seems to have “lost sync”. Fortunately I have my sensors are easy to disconnect and reconnect (thus cycling power on the sensor). My suggestion would be to modify your software on the ESP8266 so that if you’re getting “garbage” or (more likely) nothing from the sensors, it sends out an error message. (I’m toying with modifying my design to have a MOSFET on the I2C power line, so that the ESP8266 can “force reset” on the sensors.)