JTAG pins 12, 13, 14, & 15

[ezed413]

For the 4-pins used for JTAG, can they be switched on/off via software or do they require hardware binding? In other words, can they be used for both programing and application software based on an internal mux which can be triggered somehow?

[ESP_Sprite]

You can use them as normal GPIOs (or peripheral pins routed over the GPIO matrix) by configuring them as such in ESP-IDF. Obviously, they'll loose their function as JTAG pins when you do that. You can then programmatically restore that function by re-assigning the JTAG signals to the pins using the IOMUX.

[maskemaske]

You can use them as normal GPIOs (or peripheral pins routed over the GPIO matrix) by configuring them as such in ESP-IDF.

Please advise on how to do so, for ESP32.

Simply configuring them as output, disabling pull-resistors, and then setting a level does not work.

Thanks

[ESP_Sprite]

I think gpio_reset() should configure any pin to GPIO mode.

[projix]

If someone finds this thread with an ESP32-S3, you also need to gall gpio_reset() on pins 39, 40, 41, 42.
Even though the manual says that if USB JTAG is enabled (which it is by default), then these pins are working.
If you do not call gpio_reset() on them first, they will not react at all.