ESP32-WROVER-IE burn fuse to set VDD_SDIO

[Jonathan2892]

Hi,

I have a esp32-wrover-ie and I am a little bit confused about the voltage of param and flash. From the docs I read "Internal pull-up resistor (R9) for MTDI is not populated in the module, as the flash and SRAM in the module only support a power voltage of 3.3 V (output by VDD_SDIO)." (https://www.espressif.com/sites/default ... eet_en.pdf page 7)

When I look into the Efuse I get:

Code: Select all

XPD_SDIO_FORCE (BLOCK0):                           Ignore MTDI pin (GPIO12) for VDD_SDIO on reset     = False R/W (0b0)
XPD_SDIO_REG (BLOCK0):                             If XPD_SDIO_FORCE, enable VDD_SDIO reg on reset    = False R/W (0b0)
XPD_SDIO_TIEH (BLOCK0):                            If XPD_SDIO_FORCE & XPD_SDIO_REG                   = 1.8V R/W (0b0)

So on what voltage is flash and param? 3.3 or 1.8V? When I pull gpio12 to HIGH or to GND nothing changes and the esp can start in both setups. Does that mean that gpio12 has nothing to do with the VDD_SDIO on the wrover-ie modules?

(Background information: I want to use gpio12 as normal gpio. So why not burn the VDD_SDIO to fixed voltage? It will never change anyway...)

One more question out of curiosity: When I flash the firmware I can see that the module version is V3. In the Efuse setup the silicon revision is 2. Is this right? Or do I have a fake module?

Best,
Jonathan

[ESP_Sprite]

Yes, those modules normally use GPIO12 as a bootstrap pin, and you can see that your fuses reflect that as they do not force a VDD_SDIO voltage. Your chip may still work when you use the wrong VDD_SDIO, but it's likely that you're running everything outside of the flash specs and there's no guarantee it will keep working under all circumstances. Better to burn the fuse to force the chip to 3.3V if you want to use the IO as a generic IO pin.