jjuduma wrote: ↑

Sat Sep 19, 2020 6:33 am

I dont really need the flash except for bulk data storage

Common misconception but the flash is constantly in use by esp32 cache to access application code. So no don't switch the ldo to 1.8v, use a level shifter.

Search for CP21xx Device Customization Software

at-least 5 modules out of 25 modules

If the same flashing process is failing on only a few modules it sounds like a hardware issue

The intention is so you can use esp32 without a flash chip connected to a host processor over sdio like a more traditional wifi chip. You would load a simple wifi firmware to ram on boot over sdio and all the network processing would be done on the host processor. It's not really supported, at least...

That may or may not be your problem, there is a list of psram chipid here, but it was removed later. https://github.com/espressif/esp-idf/co ... eedd4cc720

Have you tried SPIRAM_2T_MODE in idf v4.3?

There is no separate secure element hardware with private key storage. If you need that maybe you want wroom32-se? Otherwise just rely on secure boot and flash encryption to protect your keys. You could sign and verify your key partitions with the same PKI.

Are you sure there is no delay on the sender side? Check with Wireshark?

They should be free but they are 1.8v gpios so you might be Browning out the sdio 1.8v internal regulator by driving a buzzer