We are working indoors in a lab. The EM7455 is driven by a debian processor over the USB bus.
One of the EM7455’s was connected over Sprint for about 5 days. The technician said the part was real hot and then the EM7455 would not acquire the correct IP address. Eventually the kernel drivers would not establish the virtual IP device called eth1. Another EM7455’s LED will not light up but the voltage regulator is 3.3VDC.
We used to think the wrong IP address was a Sprint problem but now we think the part is getting damaged when the temperature is getting too hot. The temperature will go down after a reboot. I am running a python thread that reads the temp using AT!PCTEMP. I send a message to the log if the temp > 65.0 degC.
I think I am going to have my EM7455.py thread pull down the EM7455’s Reset pin if the temp exceeds 60 degC. I will wait 10 minutes and then pull up the Reset pin to try it again.
I don’t see how a 3.3VDC device can get so hot. I am not using a EM7455 heat sync because the temp is not hot under normal conditions. We do not send that much data. I have had a controller running I my house for about a month and it never gets hot. It only happens to a few units.
I can send you my schematic if you want. I don’t have any input pins floating. I don’t know what else to try.