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Cannot program ESP32S2

Posted: Wed Nov 30, 2022 2:38 am
by enkoopa
I'm using a programmer that works fine on ESP32 designs.

https://github.com/gcormier/eflashy32
Image

I have had no issues with this to program ESP32-WROOM-32 designs.

When trying to use this to program ESP32-S2 modules, it doesn't work.

The serial is OK - if I apply power to the ESP32S2, I can see output from the device. Trying to execute a chip_id using esptool 4.4, it cannot communicate.

However, if I pull down EN to ground myself with a jumper wire on the programmer, it will succeed. I put a scope on EN and cannot see any difference between the jumper wire and the CP2102N. And as mentioned, this programmer works no problem on an ESP32 design.

This is the ESP32S2 design
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Not sure where to go next. Maybe ESP32S2 needs a weaker pullup R5 on EN? 22k? I also tried a 0.1uF on the EN pullup with no effect.

Re: Cannot program ESP32S2

Posted: Thu Dec 01, 2022 1:31 pm
by username
try putting a 10k pullup on IO0, along with a 0.1uf cap to GND. Also, keep the 0.1uf cap on the EN pin.

Re: Cannot program ESP32S2

Posted: Thu Dec 01, 2022 5:36 pm
by enkoopa
False alarm on this one - the EN and GPIO pins were accidentally swapped despite the labels.