Nope, can't seem to get speed above 20MHz to work when going through the GPIO matrix. When using native pins, I can go all the way to 80MHz.

hgptamn, if you're still watching, can you try reducing the speed to 20 and test again?

Changing the speed from 40 to 20 produces good results: .speed_mhz = 20, ERASE/WRITE/VERIFY Test... Bus std 1-1-1 Flash size 16777216 Sector size 4096 Register 1 result binary = 00000010 Register 1 result decimal = 2 Register 2 result binary = 00111100 Register 2 result decimal = 60 Erase error code...

I think we might be on to something. I'll have to re-verify my wiring, but here's what I get using hgptamn pin assignments: ERASE/WRITE/VERIFY Test... Bus std 1-1-1 Flash size 16777216 Sector size 4096 Register 1 result binary = 00000000 Register 1 result decimal = 0 Register 2 result binary = 00111...

And here's what I get when using hgptamn modified code: ERASE/WRITE/VERIFY Test... Bus std 1-1-1 Flash size 16777216 Sector size 4096 Register 1 result binary = 00000010 Register 1 result decimal = 2 Register 2 result binary = 00111100 Register 2 result decimal = 60 Erase error code: 0 <snip> I'm re...

This is what I get when I use the original code from github on a Winbond W25Q128FV chip: ERASE/WRITE/VERIFY Test... Bus Proto Cycles std 1-1-1 erase/write/verify successfully tested 16 sectors unaliged write successful dual 1-1-2 erase/write/verify successfully tested 16 sectors unaliged write succe...

Wow! You're much braver than I am. I would never have thought to pop the top on one of ESP32 mods to replace chips. It'll be interesting to see how things go.

That would be great, thanks!

It all "looks" good. I'm really starting to wonder if reading is actually working. Even though the esp32 SPI transactions complete normally, that's not a guarantee that they really did work since there's no success/failure response from the chip. The only thing I can think to check is the wiring and...

Good eyeballs! I totally missed that. And yes, it would matter in the bigger picture. The is an example of why I made nearly all of the methods virtual. There "seems" to be a general flash "standard", but there seems to be slight differences here an there that must be handled by chip specific code. ...

Grasping at straws here, but when was the last time you updated your esp-idf SDK? There was a bug I'd reported that "may" be relevant here and it was fixed on December 12th:

https://github.com/espressif/esp-idf/issues/1549