ICM interface with ESP32- HSPI pins Programming Issue
iharshadec opened this issue · 4 comments
I am using ESP32 HSPI pins which is 12,13 and 14 with ICM with Level Shifter to convert between 1.8v and 3.3v
I am not able to program my ESP32 after programming it once with ICM example code.
I am using Arduino + Windows environment for this.
Hello Harshad (@iharshadec ),
Pin 12 is one of the ESP32 boot control (strapping) pins. Pulling pin 12 high will cause the bootloader to fail. Perhaps there is a pull-up resistor in the level shifter circuit?
https://docs.espressif.com/projects/esptool/en/latest/esp32/advanced-topics/boot-mode-selection.html
You can use pin 12, but you need to ensure it is isolated until the boot is complete.
Best wishes,
Paul
I am not sure what is correct way to isolate Pin 12 until boot is done. Any suggestion?
It depends on your project. We have used this circuit successfully to isolate pins 2, 12 and 15. When RESET is low, switch 4 is open, so PWREN is low. Because PWREN is low, ESP2, ESP12 and ESP15 are isolated. PWREN stays low until ESP32 is configured as an output and pulled high.
Thank you @PaulZC