ESP32 Forum

Hey everyone,

I have an ESP32-WROVER-B on multiple custom PCBs with an issue I can't explain:

- If I set the menuconfig -> Serial flasher config -> Flash SPI speed to 26, 40, or 80MHz I can flash an image successfully but I will receive a checksum error when the device reboots
- If I set the menuconfig -> Serial flasher config -> Flash SPI speed to 20MHz everything seems to run OK

Is this SPI flash speed expected? If not, any ideas what might cause my issues?

Thanks!
-AD

What does the custom PCB look like? Do you have anything connected to the flash pins that may affect operation?

Also make sure you are not pulling up gpio12 or have set the vdd_sdio efuse to 3.3v

ESP_Sprite:

You're right on the money: I had an I2C device hanging off of GPIO21 and 22 which also happen to be used by SPI flash on the ESP32-WROVER. This was causing my SPI Flash to be very flaky.

Removing my device from those two GPIOs cleared everything up.

Thanks for the pro-tip!
-AD

Do you mean pad 21&22 aka gpio 7&8?