ESP8266 Community Forum

- Thu Jun 25, 2015 12:44 pm #21644 Wow how frustrating!

I have used maybe a dozen ESP-01s and several ESP-12's and never had any do this.

I did fry a couple of them but it was through my own mistake

Good luck,
John

- Thu Jun 25, 2015 1:20 pm #21650 This sounds like a latch-up-effect
https://en.wikipedia.org/wiki/Latchup
Can you rule ESD out? You could try to include some zener diodes (3V6) in your circuit.

- Thu Jun 25, 2015 1:52 pm #21656

Just as an aid perhaps, I connect both pins to high direct . Have not bothered to implement any resistors yet .

That is not a good practice on "undetermined I/O state", it is only good and it is "known Input Only".

It's guaranteed that RESET and CHIP_EN pins are inputs when the ESP8266 is first powered up, so as long as the user code doesn't ever make them outputs, shorting them to high shouldn't cause a problem.

Kenn, can you tell me where I might find some detail about this please?

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG

- Thu Jun 25, 2015 2:02 pm #21658

It's guaranteed that RESET and CHIP_EN pins are inputs when the ESP8266 is first powered up, so as long as the user code doesn't ever make them outputs, shorting them to high shouldn't cause a problem.

Kenn, can you tell me where I might find some detail about this please?

Only that it must be true since CHIP_EN is always read at startup, right? And RESET must expect to be hit at any time...

I do note that according to this hardware doc, the 'official' ESP8266 evaluation board uses a 5k pullup on CHIP_EN and 50 ohms in series with the reset switch and ground.