stm32-usbd-audio-example/src/main.rs

#![no_main]
#![no_std]
use defmt_rtt as _; // global logger

use panic_probe as _;
use stm32f1xx_hal as _;

// same panicking *behavior* as `panic-probe` but doesn't print a panic message
// this prevents the panic message being printed *twice* when `defmt::panic` is invoked
#[defmt::panic_handler]
fn panic() -> ! {
    cortex_m::asm::udf()
}

use rtic::app;

#[app(device = stm32f1xx_hal::pac, peripherals = true, dispatchers = [SPI2])]
mod app {

    use stm32f1xx_hal::{
        gpio::{gpioc, Output, PushPull},
        prelude::*,
        usb::{Peripheral, UsbBus},
    };

    use usb_device::class_prelude::UsbBusAllocator;
    use usb_device::prelude::*;
    use usbd_audio::{AudioClass, AudioClassBuilder, Format, StreamConfig, TerminalType};

    use systick_monotonic::Systick;

    #[monotonic(binds = SysTick, default = true)]
    type MonoTimer = Systick<1_000>;

    #[shared]
    struct Shared {
        usb_dev: UsbDevice<'static, UsbBus<Peripheral>>,
        usb_audio: AudioClass<'static, UsbBus<Peripheral>>,
        board_led: gpioc::PC13<Output<PushPull>>,
    }

    #[local]
    struct Local {}

    #[init(local = [usb_bus: Option<UsbBusAllocator<UsbBus<Peripheral>>> = None])]
    fn init(mut cx: init::Context) -> (Shared, Local, init::Monotonics) {
        let mut flash = cx.device.FLASH.constrain();
        let rcc = cx.device.RCC.constrain();

        // Freeze the configuration of all the clocks in the system and store the frozen frequencies in
        // `clocks`
        let clocks = rcc
            .cfgr
            .use_hse(8.MHz())
            .sysclk(72.MHz())
            .pclk1(36.MHz())
            .freeze(&mut flash.acr);

        defmt::info!("Clock Setup done");

        // Acquire the GPIOC peripheral
        let mut gpioa = cx.device.GPIOA.split();
        //let mut gpiob = cx.device.GPIOB.split();
        let mut gpioc = cx.device.GPIOC.split();

        let board_led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);
        defmt::info!("ADC Setup done");

        // BluePill board has a pull-up resistor on the D+ line.
        // Pull the D+ pin down to send a RESET condition to the USB bus.
        // This forced reset is needed only for development, without it host
        // will not reset your device when you upload new firmware.
        let mut usb_dp = gpioa.pa12.into_push_pull_output(&mut gpioa.crh);
        let mut delay = cortex_m::delay::Delay::new(cx.core.SYST, clocks.sysclk().to_Hz());
        usb_dp.set_low();
        delay.delay_ms(10);
        cx.core.SYST = delay.free();

        let usb_dm = gpioa.pa11;
        let usb_dp = usb_dp.into_floating_input(&mut gpioa.crh);

        let usb = Peripheral {
            usb: cx.device.USB,
            pin_dm: usb_dm,
            pin_dp: usb_dp,
        };

        let usb_bus: &'static _ = cx.local.usb_bus.insert(UsbBus::new(usb));

        let usb_audio = AudioClassBuilder::new()
            .input(
                StreamConfig::new_discrete(Format::S16le, 1, &[48000], TerminalType::InMicrophone)
                    .unwrap(),
            )
            .output(
                StreamConfig::new_discrete(Format::S16le, 1, &[48000], TerminalType::OutSpeaker)
                    .unwrap(),
            )
            .build(&usb_bus)
            .unwrap();

        let usb_dev = UsbDeviceBuilder::new(&usb_bus, UsbVidPid(0x16c0, 0x27dd))
            .max_packet_size_0(64)
            .manufacturer("Kiffie Labs")
            .product("Audio port")
            .serial_number("42")
            .build();

        let mono = Systick::new(cx.core.SYST, clocks.sysclk().to_Hz());

        (
            Shared {
                usb_dev,
                usb_audio,
                board_led,
            },
            Local {},
            init::Monotonics(mono),
        )
    }

    #[task(binds = USB_HP_CAN_TX, shared = [usb_dev, usb_audio])]
    fn usb_tx(cx: usb_tx::Context) {
        defmt::info!("usb_tx called");
        let mut usb_dev = cx.shared.usb_dev;
        let mut usb_audio = cx.shared.usb_audio;

        (&mut usb_dev, &mut usb_audio).lock(|usb_dev, usb_audio| {
            if !usb_dev.poll(&mut [usb_audio]) {
                return;
            }
        });
    }

    #[task(binds = USB_LP_CAN_RX0, shared = [usb_dev, usb_audio])]
    fn usb_rx0(cx: usb_rx0::Context) {
        defmt::info!("usb_rx called");
        let mut usb_dev = cx.shared.usb_dev;
        let mut usb_audio = cx.shared.usb_audio;

        (&mut usb_dev, &mut usb_audio).lock(|usb_dev, usb_audio| {
            if !usb_dev.poll(&mut [usb_audio]) {
                return;
            }

            //TODO: Do something with usb_audio.read();
        });
    }

    #[idle(shared = [usb_audio, board_led])]
    fn idle(mut cx: idle::Context) -> ! {
        defmt::info!("Idle Task");
        let sinetab = [
            0i16, 4276, 8480, 12539, 16383, 19947, 23169, 25995, 28377, 30272, 31650, 32486, 32767,
            32486, 31650, 30272, 28377, 25995, 23169, 19947, 16383, 12539, 8480, 4276, 0, -4276,
            -8480, -12539, -16383, -19947, -23169, -25995, -28377, -30272, -31650, -32486, -32767,
            -32486, -31650, -30272, -28377, -25995, -23169, -19947, -16383, -12539, -8480, -4276,
        ];
        let sinetab_le = unsafe { &*(&sinetab as *const _ as *const [u8; 96]) };

        loop {
            defmt::info!("Writing samples");
            cx.shared.usb_audio.lock(|usb_audio| {
                usb_audio.write(sinetab_le).ok();
            });
            rtic::export::wfi();
        }
    }
}