ESP32 Flash SPI Speed Issues

[autodog]

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

[ESP_Sprite]

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

[WiFive]

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

[autodog]

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

[WiFive]

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