What does gpio_matrix_in and gpio_matrix_out do? Where is the code?

[clarkster]

I continue to try (unsuccessfully) to connect an rmt output to a gpio AND to a pcnt input. I am still confused by Chapter 4 of the TRM even though some have tried to explain it to me.

It would help if I could find the c code for gpio_matrix_in and gpio_matrix_out. I have searched the esp/components folder and cannot find the source code for these functions. They are not in gpio.c. Where is that code?

[WiFive]

They are in rom, no source code. But the problem you are having may be related to certain gpio utility functions disabling input when configuring output and vice versa.

https://github.com/DavidAntliff/esp32-o ... #L413-L423

[clarkster]

Thanks for your help. I have inspected the GPIO configuration code in rmt.c and in pcnt.c and I think I see how this can happen. I also looked at the newest TRM and you guys have done a good job revising Chapter 4. I think with a little more work I will figure this out.

[prout_boudin]

Hello,

I'm currently looking for gpio_matrix_in() documentation... I cannot find anything regarding the doc on that... could you help ?

[clarkster]

Well, as WiFive stated above, the source code is not available, but you can still find information on gpio_matrix_in in multiple places.

The first is gpio.h. It is located in - [Your ESP-IDF Folder] / components / esp32 / include / rom / gpio.h.

Next if you look in your ESP-IDF examples folder you will find several examples that use this instruction: i2c.c, i2s.c, pcnt.c, mcpwn.c, rmt.c, uart.c - and others.

Lastly, Kolban's Book on the ESP32 discusses this instruction. https://leanpub.com/kolban-ESP32

Hope this helps...

[SparkyNZ]

Whereabouts is the API documentation for gpio_matrix_in() ? I have some third-party code that's using it that won't compile.

[MicroController]

https://github.com/espressif/esp-idf/bl ... pio.h#L142