[ESP32-PICO-V3-02] Internal Flash voltage problem

ESP32-PICO-V3-02 has internal 8MB SPI flash memory that is 3.3V operating.

First of all, you can download datasheet from ESPRESSIF.COM that is the official Espressif website. 

 

The pin GPIO12(MTDI) is a boot strap pin for selecting level of VDD_SPI voltage that is for internal flash memory.  So, it must be HIGH at booting sequence.

 

After compelting booting, GPIO12 can be utilizied for normal GPIO. 

This is what I understand.

 

but, after booting is finished(working OK), When I try to use GPIO12 as a input pin and pull down to low(GND), then, SPI-Flash volatge is coming down to 1.8V. !!!!

 

 

 

 

 

Solution : It can be fixed to 3.3V simplely writing efuse bit.

   

you can refer to below site. 

github.com/espressif/esptool/wiki/espefuse 

 

espefuse.py set_flash_voltage 3.3V

**  I don't test other PICO series.