ESP8266 Community Forum

- Sat Sep 26, 2015 2:55 pm #29940 When I recycle power with terminal open with the right baudrate, I get a message on the boot mode (1,0), so I assume it enters the UART mode correctly.

This and ESP working correctly in normal mode makes me think that maybe it is just the RX pin on ESP that is not working. Is it possible that only that has been fried? I have tried to use voltage divider/level shifter since then, but maybe it is permanently damaged... Is there a way I could diagnose that?

- Sun Sep 27, 2015 3:51 pm #30005

... maybe it is just the RX pin on ESP that is not working. Is it possible that only that has been fried? I have tried to use voltage divider/level shifter since then, but maybe it is permanently damaged... Is there a way I could diagnose that?

Hang an oscilloscope if you have one, or even just a resistor and a LED, onto the ESP's RX pin. If there's activity on the RX pin when the PC terminal sends something, or tries to flash the ESP, but there's no response from it... could be the ESP. If you don't see activity at the RX pin, then it's probably a connection problem (most likely) or maybe the USB to serial.

- Sun Sep 27, 2015 4:09 pm #30009 I do not have that problem, or any other, with that board anymore... I was stupid enough to regulate the voltage - I wanted it to be perfect! - without checking first that the board is disconnected... I was sure that it was.

It seems that the magic smoke was indeed required, as the operation degraded significantly. Funnily enough, it still boots, but stops at "waiting for host". And it gets really hot really quick. I guess it is time for another Chinese delivery. This time I will be wiser... I'll order some spares for frying purposes.