kb-firmware/src/main.rs

#![no_std]
#![no_main]

use core::sync::atomic::{AtomicBool, Ordering};

use defmt::{info, warn};
use embassy_executor::Spawner;
use embassy_futures::join::join;
use embassy_rp::{bind_interrupts, gpio::{Input, Level, Output, Pull}, peripherals::USB, usb::{Driver, InterruptHandler}};
use embassy_time::{Duration, Timer};
use embassy_usb::{Builder, Config, Handler, class::hid::{HidReaderWriter, ReportId, RequestHandler, State}, control::OutResponse};
use usbd_hid::descriptor::{KeyboardReport, SerializedDescriptor};
use {defmt_rtt as _, panic_probe as _};

pub struct Debouncer<'a> {
    input: Input<'a>,
    debounce: Duration,
}

impl<'a> Debouncer<'a> {
    pub fn new(input: Input<'a>, debounce: Duration) -> Self {
        Self { input, debounce }
    }

    pub async fn debounce_low(&mut self) -> Level {
        loop {
            let l1 = self.input.get_level();

            self.input.wait_for_low().await;

            Timer::after(self.debounce).await;

            let l2 = self.input.get_level();
            if l1 != l2 {
                break l2;
            }
        }
    }

    pub async fn debounce_high(&mut self) -> Level {
        loop {
            let l1 = self.input.get_level();

            self.input.wait_for_high().await;

            Timer::after(self.debounce).await;

            let l2 = self.input.get_level();
            if l1 != l2 {
                break l2;
            }
        }
    }
}

bind_interrupts!(struct Irqs {
    USBCTRL_IRQ => InterruptHandler<USB>;
});

#[embassy_executor::main]
async fn main(_spawner: Spawner) -> () {
    let p = embassy_rp::init(Default::default());

    let driver = Driver::new(p.USB, Irqs);

    let mut config = Config::new(0x1234, 0xabcd);
    config.manufacturer = Some("Lukrecja");
    config.product = Some("kb-prototype");
    config.serial_number = Some("00000000");
    config.composite_with_iads = false;
    config.device_class = 0x00;
    config.device_sub_class = 0x00;
    config.device_protocol = 0x00;

    let mut config_descriptor = [0; 256];
    let mut bos_descriptor = [0; 256];
    let mut msos_descriptor = [0; 256];
    let mut control_buf = [0; 64];
    let mut request_handler = KbRequestHandler {};
    let mut device_handler = KbDeviceHandler::new();

    let mut state = State::new();

    let mut builder = Builder::new(
        driver,
        config,
        &mut config_descriptor,
        &mut bos_descriptor,
        &mut msos_descriptor,
        &mut control_buf,
    );

    builder.handler(&mut device_handler);

    let config = embassy_usb::class::hid::Config {
        report_descriptor: KeyboardReport::desc(),
        request_handler: None,
        poll_ms: 60,
        max_packet_size: 64,
    };

    let hid = HidReaderWriter::<_, 1, 8>::new(&mut builder, &mut state, config);

    let mut usb = builder.build();

    let usb_fut = usb.run();

    let mut led = Output::new(p.PIN_25, Level::Low);
    let mut switch_input = Debouncer::new(Input::new(p.PIN_0, Pull::Up), Duration::from_millis(20));
    switch_input.input.set_schmitt(true);

    let (reader, mut writer) = hid.split();

    let in_fut = async {
        loop {
            defmt::info!("waiting for low");
            led.set_low();
    
            switch_input.debounce_low().await;
    
            info!("got low");
            led.set_high();
    
            let report = KeyboardReport {
                keycodes: [4, 0, 0, 0, 0, 0],
                leds: 0,
                modifier: 0,
                reserved: 0,
            };
    
            match writer.write_serialize(&report).await {
                Ok(()) => info!("report sent"),
                Err(e) => warn!("failed to send: {:?}", e),
            };
    
            switch_input.debounce_high().await;
            info!("got high");
    
            let report = KeyboardReport {
                keycodes: [0, 0, 0, 0, 0, 0],
                leds: 0,
                modifier: 0,
                reserved: 0,
            };
    
            match writer.write_serialize(&report).await {
                Ok(()) => info!("report sent"),
                Err(e) => warn!("failed to send: {:?}", e),
            };       
        }
    };

    let out_fut = async {
        reader.run(false, &mut request_handler).await;
    };
    join(usb_fut, join(in_fut, out_fut)).await;
}

struct KbRequestHandler {}

impl RequestHandler for KbRequestHandler {
    fn get_report(&mut self, _id: ReportId, _buf: &mut [u8]) -> Option<usize> {
        info!("get report");
        None
    }

    fn set_report(&mut self, _id: ReportId, data: &[u8]) -> OutResponse {
        info!("set report: {=[u8]}", data);
        OutResponse::Accepted
    }

    fn set_idle_ms(&mut self, _id: Option<ReportId>, dur: u32) {
        info!("set idle rate to {}", dur);
    }

    fn get_idle_ms(&mut self, _id: Option<ReportId>) -> Option<u32> {
        info!("get idle rate");
        None
    }
}

struct KbDeviceHandler {
    configured: AtomicBool,
}

impl KbDeviceHandler {
    fn new() -> Self {
        Self {
            configured: AtomicBool::new(false),
        }
    }
}

impl Handler for KbDeviceHandler {
    fn enabled(&mut self, enabled: bool) {
        self.configured.store(false, Ordering::Relaxed);
        if enabled {
            info!("device enabled");
        } else {
            info!("device disabled");
        }
    }

    fn reset(&mut self) {
        self.configured.store(false, Ordering::Relaxed);
        info!("bus reset, Vbus current limit is 100mA");
    }

    fn addressed(&mut self, addr: u8) {
        self.configured.store(false, Ordering::Relaxed);
        info!("USB address set to: {}", addr);
    }

    fn configured(&mut self, configured: bool) {
        self.configured.store(configured, Ordering::Relaxed);
        if configured {
            info!("device configured")
        } else {
            info!("device no longer configured");
        }
    }
}