Any hope for damaged WiPy 2

[dvogel]

I damaged my WiPy 2 by plugging into the expansion board the wrong way. It will not allow a wifi connection or connect to PyMakr, nor will it go into update mode by grounding G23. I also tried a factory reset with 3.3v on G28. Is there any hope for any functionality for this device or should I pitch it?

[livius]

@dvogel said in Any hope for damage WiPy 2:

First - what power source did you use when you put wipy wrongly?
It is important to predict what can be broken.
Did you tried with any TTL USB to UART converter connected to your wipy without expansion board?

[dvogel]

It was in the expansion board connected to computer/USB so power source was USB 5v. At the very least G28 was receiving ~5v, very bad! :(

Yes, I have tried using a (3.3v) TTL serial connection without the expansion board, no difference.

Actually, everytime it is powered up now it goes through the heartbeat led sequence indicating a factory reset (even without an external pullup on G28).

[livius]

@dvogel said in Any hope for damaged WiPy 2:

TTL

Without schematics really hard to tell what more you can do.
I know that it is crazy - try cold it in refrigerator and power once again - maybe some louck for you.
If not then ...

[jmarcelino]

@dvogel said in Any hope for damaged WiPy 2:

Actually, everytime it is powered up now it goes through the heartbeat led sequence indicating a factory reset (even without an external pullup on G28).

That means the processor is at least somewhat working and running esp32/bootloader/bootmgr.c

Do you see any messages via the serial console?
Can you measure the voltage at G28?

I wonder what happens if you pull G28 down - connect it to GND - but try it through a resistor first, say 4.7k

If it's just that pin that's hopelessly 'stuck' high (maybe the ESD protection diode shorted) you can also try disabling the safe boot check in esp32/bootloader/bootmgr.c

[livius]

@jmarcelino
as always - really good tips - especially with pull down resistor
and advanced step - disabling safe boot sequence in source

[dvogel]

Update on this. I am embarrassed to have to admit that it turns out the unit I have is a WiPy 1 (not 2 - stupid me!). With that information, it is clear the the module largely works, except for pin 28 which appears to be hopelessly held high inside, regardless of what I attach to it. As suggested, this means I will have to disable the safe boot process (or assign a different pin) to update it. Can someone point me to something that might help me through that process? Thanks.

[Frida]

Maybe this can help you!
http://forum.micropython.org/viewtopic.php?f=11&t=1228