Implement twitching mouse

Cargo.toml

@@ -11,3 +11,6 @@ cortex-m-rt = "0.7.2"
 rp-pico = "0.6.0"
 panic-halt = "0.2.0"
 defmt = "0.3.0"
+usb-device = "0.2.9"
+usbd-hid = "0.6.1"
+critical-section = "1.1.1"

src/main.rs

@@ -5,19 +5,35 @@
 // be linked)
 use panic_halt as _;
 
-// Pull in any important traits
-use rp_pico::{
+use rp_pico as bsp;
+
+use bsp::{
     entry,
-    hal::{self, pac, prelude::*},
+    hal::{
+        self, pac,
+        pac::{interrupt, Interrupt},
+        prelude::*,
+        usb::UsbBus,
+    },
 };
 
-/// Entry point to our bare-metal application.
-///
-/// The `#[entry]` macro ensures the Cortex-M start-up code calls this function
-/// as soon as all global variables are initialised.
-///
-/// The function configures the RP2040 peripherals, then blinks the LED in an
-/// infinite loop.
+use cortex_m::delay::Delay;
+
+use usb_device::{class_prelude::*, prelude::*};
+use usbd_hid::{
+    descriptor::{MouseReport, SerializedDescriptor},
+    hid_class::HIDClass,
+};
+
+/// The USB Device Driver (shared with the interrupt).
+static mut USB_DEVICE: Option<UsbDevice<UsbBus>> = None;
+
+/// The USB Bus Driver (shared with the interrupt).
+static mut USB_BUS: Option<UsbBusAllocator<UsbBus>> = None;
+
+/// The USB Human Interface Device Driver (shared with the interrupt).
+static mut USB_HID: Option<HIDClass<UsbBus>> = None;
+
 #[entry]
 fn main() -> ! {
     // Grab our singleton objects
@@ -42,26 +58,70 @@ fn main() -> ! {
     .ok()
     .unwrap();
 
-    // The delay object lets us wait for specified amounts of time (in
-    // milliseconds)
-    let mut delay = cortex_m::delay::Delay::new(core.SYST, clocks.system_clock.freq().to_Hz());
+    unsafe {
+        USB_BUS = Some(UsbBusAllocator::new(UsbBus::new(
+            pac.USBCTRL_REGS,
+            pac.USBCTRL_DPRAM,
+            clocks.usb_clock,
+            true,
+            &mut pac.RESETS,
+        )))
+    };
 
-    // The single-cycle I/O block controls our GPIO pins
-    let sio = hal::Sio::new(pac.SIO);
+    unsafe {
+        USB_HID = Some(HIDClass::new(
+            USB_BUS.as_ref().unwrap(),
+            MouseReport::desc(),
+            60,
+        ));
+    }
 
-    // Set the pins up according to their function on this particular board
-    let pins = rp_pico::Pins::new(
-        pac.IO_BANK0,
-        pac.PADS_BANK0,
-        sio.gpio_bank0,
-        &mut pac.RESETS,
-    );
+    unsafe {
+        USB_DEVICE = Some(
+            UsbDeviceBuilder::new(USB_BUS.as_ref().unwrap(), UsbVidPid(0x046d, 0x101b))
+                .manufacturer("Logitech")
+                .product("Marathon Mouse/Performance Plus M705")
+                .serial_number("B14D65DA")
+                .build(),
+        );
+    }
 
-    // Set the LED to be an output
-    let mut led_pin = pins.led.into_push_pull_output();
+    unsafe {
+        pac::NVIC::unmask(Interrupt::USBCTRL_IRQ);
+    }
 
-    // Blink the LED at 1 Hz
-    loop {}
+    let mut delay = Delay::new(core.SYST, clocks.system_clock.freq().to_Hz());
+
+    loop {
+        mouse_move(&mut delay, 4);
+        mouse_move(&mut delay, -4);
+    }
 }
 
-// End of file
+fn mouse_move(delay: &mut Delay, v: i8) {
+    delay.delay_ms(100);
+
+    let rep = MouseReport {
+        x: 0,
+        y: v,
+        buttons: 0,
+        wheel: 0,
+        pan: 0,
+    };
+    push_mouse_movement(rep).unwrap_or(0);
+}
+
+/// with interrupts disabled, to avoid a race hazard with the USB IRQ.
+fn push_mouse_movement(report: MouseReport) -> Result<usize, usb_device::UsbError> {
+    critical_section::with(|_| unsafe { USB_HID.as_mut().map(|hid| hid.push_input(&report)) })
+        .unwrap()
+}
+
+#[allow(non_snake_case)]
+#[interrupt]
+unsafe fn USBCTRL_IRQ() {
+    // Handle USB request
+    let usb_dev = USB_DEVICE.as_mut().unwrap();
+    let usb_hid = USB_HID.as_mut().unwrap();
+    usb_dev.poll(&mut [usb_hid]);
+}