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TaylorHokanson / CAAint

An open source badge project for noobs, artists, and the interdimensionally-curious
MIT License
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Cannot program while attached to PCB #1

Closed TaylorHokanson closed 6 years ago

TaylorHokanson commented 6 years ago

Seems like this is a known issue: https://github.com/espressif/arduino-esp32/issues/409

Tried:

To Try:

TaylorHokanson commented 6 years ago

This looks promising:

"The same goes with GPIO pins 0, 1, 2, and 3. As far as I can tell, these pins should not be used for general purpose GPIO. If you use 0 or 2 I understand you risk screwing up the boot of the board. (I suppose you could use them for output after the board is booted. And I suppose you could use them for input, but you better not have anything connected before the processor boots.) If you use 1 or 3, you screw up the UART and you cannot monitor the board. (I suppose there is a use case where you don't need to monitor the board....probably after the board goes into production....if you trust never being able to monitor a board once the design has gone into production and the UART pins are used as GPIO.)" via

TaylorHokanson commented 6 years ago

Aha! I cut both traces to pins 0 and 2. Now we can program even when the TTGO is plugged into the PCB.

pawelcern commented 6 years ago

Hi. I had similar problem with custom board based on ESP-WROOM-32 even when all SPI related GPIOs were free. The problem was I had GPIO12 pulled up at boot. According to ESP32 datasheet, GPIO12 (MTDI) is somehow responsible for FLASH voltage.

julian616 commented 6 years ago

what pins should I use for output and input, I had the same problem with pin 2 and 12.