ESP32 Forum

Posted: **Thu Jan 18, 2018 3:02 am**

Somewhat of an academic question: is it possible to use the GPIO Matrix or IO Mux to somehow send an incoming level on an input GPIO to an output GPIO?

I know this is a bit strange - why not just electrically connect the circuit on the output GPIO to the input signal, you may ask - what I'm considering here is directing an incoming signal level (on, say, GPIO 5) to the onboard LED (which is GPIO 2 in my case), so that there is a visual indicator of the signal. I'm using PCNT to count the input signal, and I don't think there's a pass-through output that I can route to GPIO 2. The signal may be fast (up to kHz) so I can't really drive GPIO 2 in software. I could (and do) use an external LED, however the onboard LED is just sitting there so I was wondering if I could drive it in this manner.

Part of this is just my curiosity around the IO Mux & GPIO Matrix and knowing whether this is possible will help my understanding of these subsystems.

Posted: **Thu Jan 18, 2018 7:04 am**

Maybe
https://github.com/espressif/esp-idf/bl ... ram.c#L540

Posted: **Mon Jan 22, 2018 9:56 pm**

Thanks for that link, it's exactly what I needed to see.

Code: Select all

    // route incoming frequency signal to onboard LED
    gpio_matrix_in(GPIO_FREQ_SIGNAL, SIG_IN_FUNC228_IDX, false);
    gpio_matrix_out(GPIO_LED, SIG_IN_FUNC228_IDX, false, false);

Works perfectly.

Posted: **Thu Feb 08, 2018 4:11 am**

+1
same here - exactly option what i did searched

txs @WiFive for your reminder at this theme.

best wishes
rudi

ESP32 Forum

Route input GPIO to output GPIO via IO Mux or GPIO Matrix?

Route input GPIO to output GPIO via IO Mux or GPIO Matrix?

Re: Route input GPIO to output GPIO via IO Mux or GPIO Matrix?

Re: Route input GPIO to output GPIO via IO Mux or GPIO Matrix?

Re: Route input GPIO to output GPIO via IO Mux or GPIO Matrix?