Questions about reset

[chungwong]

Thanks for sharing the code and I have learnt a lot from it.

I am still new to ESP32 and have two questions about thow it works.

How does this line work?

    // https://github.com/javiser/esp32-c3-32s-kit-example/blob/main/src/main.rs#L51
    let mut button = Button::new(pins.gpio9.into_input()?, WhenPressed::Low);

1. How does GPIO9 relate to the reset button?
2. So when the reset button is pressed, would the program got reset? How does the variableshow_mode retained the value through a reset at https://github.com/javiser/esp32-c3-32s-kit-example/blob/main/src/main.rs#L92?

[javiser]

Hi @chungwong,
first of all sorry for the late reply, I was on holiday 😄. Second, I am really glad you found this project and that it was useful for you, even if it came from a rust beginner as I was (still am...) at the time I created this project. Another disclaimer in advance: in the meantime I moved to the C/C++ implementation using the official ESP-IDF framework from espressif, so that I don't feel like an expert in ESP32 with rust.

That being said, here the answer to your questions: the GPIO9 is NOT the reset button of the board, but the other one, which I use in my example as input for the demo. You can find the detailed schematics of the board here: https://www.waveshare.com/w/upload/4/46/Nodemcu-esp-c3-32s-kit-schematics.pdf . I am not sure how did you relate this to the reset, but since it is not the reset button, this also answers your second question: if there is not a reset, that's how I retain the value 😉

I hope this helps you further and have fun learning ESP32 and rust!

[chungwong]

Thank you very much for your reply.

I did find out what caused my confusion. The offical ESP32 C3 board has a different layout for the button as illustrated here. The position of the two buttons are swapped in Ai-Thinker's version.

Thanks again for your kindly help!