Simple button press Embassy task seems to not run

[aidengk-iris]

Dear all,

I'm trying to use esp-hal with Embassy to monitor a button press event on an ESP32C3.

My main.rs comprises simply a button press monitoring task and a main task.
The main task does nothing other than some peripheral initialization. The button press task waits for a button press and prints a message.

My issue is that the button press monitoring task does not print anything when I press the button.

However, when I wait for button presses in the main task, I do see an info message printed.

I suppose I made some obvious mistake in using Embassy and esp-hal.
I would appreciate any insight and suggestions.

Please see the code and the dependencies in toml in the followings:

Thank you very much.

My implementation:

#![no_std]
#![no_main]

use embassy_executor::Spawner;
use esp_backtrace as _;
use esp_hal::{gpio::{Input, Io, Pull}, timer::timg::TimerGroup};
use esp_println::println;

// task to monitor button press. Button is pulled high during idle phase
#[embassy_executor::task]
async fn monitor_pd_voltage_up_button(mut button: Input<'static>){
    loop {
        button.wait_for_falling_edge().await;
        println!("PD Voltage Up button pressed");    
    }
}

#[esp_hal_embassy::main]
async fn main(spawner: Spawner) {
    let peripherals = esp_hal::init(esp_hal::Config::default());
    
    // Initialize embassy with timer0.  esp_hal_embassy::init, before the first timer-related operation.
    let timer_group_0 = TimerGroup::new(peripherals.TIMG0);
    esp_hal_embassy::init(timer_group_0.timer0);

    // Initialize gpio pins 
    let io = Io::new(peripherals.GPIO, peripherals.IO_MUX);
    let pd_voltage_up_button = Input::new(io.pins.gpio0, Pull::Up);

    // spawn the button monitor task
    match spawner.spawn(monitor_pd_voltage_up_button(pd_voltage_up_button)){
        Ok(_) => println!("INFO: Spawned PD Voltage Up task"),
        Err(_) => println!("ERROR: Failed to spawn PD Voltage Up task"),
    }

    loop {
        // The following does behave as expected when button is pressed
        // pd_voltage_up_button.wait_for_falling_edge().await;
        // println!("PD Voltage Down button pressed");
    }
}

Dependencies:

[dependencies]
embassy-executor = "0.6.1"
embassy-sync = "0.6.0"
esp-backtrace = { version = "0.14.2", features = [
    "esp32c3",
    "exception-handler",
    "panic-handler",
    "println",
] }
esp-hal = { version = "0.21.0", features = [ "esp32c3" ] }
esp-hal-embassy = { version = "0.4.0", features = ["esp32c3"] }
esp-println = { version = "0.12.0", features = ["esp32c3", "log"] }
log = { version = "0.4.22" }

[Dominaezzz]

Remove the empty loop at the end of main. It's stealing all the CPU from your button task

[aidengk-iris]

Thank you very much @Dominaezzz !
I confirm this is the cause. I removed the empty loop in main and the button press task is behaving as expected