shuffle some threads around, stricter timing for stick readings

src/calibrate.rs

@@ -0,0 +1 @@
+pub async fn calibration_loop() {}

src/config.rs

@@ -18,7 +18,7 @@ use crate::{
 
 /// This needs to be incremented for ANY change to ControllerConfig
 /// else we risk loading uninitialized memory.
-pub const CONTROLLER_CONFIG_REVISION: u8 = 1;
+pub const CONTROLLER_CONFIG_REVISION: u8 = 2;
 
 pub const DEFAULT_NOTCH_STATUS: [NotchStatus; NO_OF_NOTCHES] = [
     NotchStatus::Cardinal,

src/gcc_hid.rs

@@ -16,7 +16,7 @@ use embassy_usb::{
 };
 use packed_struct::{derive::PackedStruct, PackedStruct};
 
-use crate::input::GCC_SIGNAL;
+use crate::input::CHANNEL_GCC_STATE;
 
 #[rustfmt::skip]
 pub const GCC_REPORT_DESCRIPTOR: &[u8] = &[
@@ -234,7 +234,7 @@ impl Handler for MyDeviceHandler {
 }
 
 #[embassy_executor::task]
-pub async fn usb_transfer_loop(driver: Driver<'static, USB>, raw_serial: [u8; 8]) {
+pub async fn usb_transfer_task(driver: Driver<'static, USB>, raw_serial: [u8; 8]) {
     let mut serial_buffer = [0u8; 64];
 
     let serial = format_no_std::show(
@@ -312,13 +312,14 @@ pub async fn usb_transfer_loop(driver: Driver<'static, USB>, raw_serial: [u8; 8]
     };
 
     let (mut reader, mut writer) = hid.split();
-    debug!("In here");
 
     let mut lasttime = Instant::now();
 
     let in_fut = async {
+        let mut gcc_subscriber = CHANNEL_GCC_STATE.subscriber().unwrap();
+
         loop {
-            let state = GCC_SIGNAL.wait().await;
+            let state = gcc_subscriber.next_message_pure().await;
             let report = get_gcinput_hid_report(&state);
             match writer.write(&report).await {
                 Ok(()) => {

src/input.rs

@@ -10,7 +10,9 @@ use embassy_rp::{
     pwm::Pwm,
     spi::Spi,
 };
-use embassy_sync::{blocking_mutex::raw::CriticalSectionRawMutex, signal::Signal};
+use embassy_sync::{
+    blocking_mutex::raw::CriticalSectionRawMutex, pubsub::PubSubChannel, signal::Signal,
+};
 use embassy_time::{Duration, Instant, Timer};
 use libm::{fmaxf, fminf};
 
@@ -23,9 +25,13 @@ use crate::{
     FLASH_SIZE,
 };
 
-pub static GCC_SIGNAL: Signal<CriticalSectionRawMutex, GcReport> = Signal::new();
+/// Used to send the button state to the usb task and the calibration task
+pub static CHANNEL_GCC_STATE: PubSubChannel<CriticalSectionRawMutex, GcReport, 1, 2, 1> =
+    PubSubChannel::new();
 
+/// Used to send the stick state from the stick task to the main input task
 static STICK_SIGNAL: Signal<CriticalSectionRawMutex, StickState> = Signal::new();
+
 const STICK_HYST_VAL: f32 = 0.3;
 const FLOAT_ORIGIN: f32 = 127.5;
 
@@ -67,6 +73,7 @@ pub enum StickAxis {
     YAxis,
 }
 
+#[link_section = ".time_critical.read_ext_adc"]
 fn read_ext_adc<'a, Acs: Pin, Ccs: Pin, I: embassy_rp::spi::Instance, M: embassy_rp::spi::Mode>(
     which_stick: Stick,
     which_axis: StickAxis,
@@ -101,6 +108,8 @@ fn read_ext_adc<'a, Acs: Pin, Ccs: Pin, I: embassy_rp::spi::Instance, M: embassy
 }
 
 /// Gets the average stick state over a 1ms interval in a non-blocking fashion.
+/// Will wait until end_time is reached before continuing after reading the ADCs.
+#[link_section = ".time_critical.update_stick_states"]
 async fn update_stick_states<
     'a,
     Acs: Pin,
@@ -128,9 +137,7 @@ async fn update_stick_states<
     let mut cx_sum = 0u32;
     let mut cy_sum = 0u32;
 
-    // TODO: lower interval possible?
+    let end_time = Instant::now() + Duration::from_micros(300); // this seems kinda magic, and it is, but
-
-    let end_time = Instant::now() + embassy_time::Duration::from_micros(500);
     let mut loop_time = Duration::from_millis(0);
 
     while Instant::now() < end_time - loop_time {
@@ -166,13 +173,11 @@ async fn update_stick_states<
             &mut spi_ccs,
         ) as u32;
 
-        // with this, we can poll the sticks at 1000Hz (ish), while updating
-        // the rest of the controller (the buttons) much faster, to ensure
-        // better input integrity for button inputs.
-        yield_now().await;
         loop_time = Instant::now() - loop_start;
     }
 
+    trace!("ADC Count: {}", adc_count);
+
     let raw_controlstick = XyValuePair {
         x: (ax_sum as f32) / (adc_count as f32) / 4096.0f32,
         y: (ay_sum as f32) / (adc_count as f32) / 4096.0f32,
@@ -382,9 +387,10 @@ fn update_button_states<
     gcc_state.buttons_1.dpad_down = btn_ddown.is_low();
 }
 
+/// Task responsible for updating the button states.
+/// Publishes the result to CHANNEL_GCC_STATE.
 #[embassy_executor::task]
-pub async fn input_loop(
+pub async fn update_button_state_task(
-    mut flash: Flash<'static, FLASH, Async, FLASH_SIZE>,
     btn_z: Input<'static, AnyPin>,
     btn_a: Input<'static, AnyPin>,
     btn_b: Input<'static, AnyPin>,
@@ -397,12 +403,8 @@ pub async fn input_loop(
     btn_x: Input<'static, AnyPin>,
     btn_y: Input<'static, AnyPin>,
     btn_start: Input<'static, AnyPin>,
-    // pwm_rumble: Pwm<'static, PWM_CH4>,
-    // pwm_brake: Pwm<'static, PWM_CH6>,
-    mut spi: Spi<'static, SPI0, embassy_rp::spi::Blocking>,
-    mut spi_acs: Output<'static, AnyPin>,
-    mut spi_ccs: Output<'static, AnyPin>,
 ) {
+    // upon loop entry, we check for the reset combo once
     if btn_a.is_low() && btn_x.is_low() && btn_y.is_low() {
         info!("Detected reset button press, booting into flash.");
         embassy_rp::rom_data::reset_to_usb_boot(0, 0);
@@ -417,14 +419,57 @@ pub async fn input_loop(
     gcc_state.cstick_x = 127;
     gcc_state.cstick_y = 127;
 
-    let controller_config = ControllerConfig::from_flash_memory(&mut flash).unwrap();
+    let gcc_publisher = CHANNEL_GCC_STATE.publisher().unwrap();
 
+    loop {
+        update_button_states(
+            &mut gcc_state,
+            &btn_a,
+            &btn_b,
+            &btn_x,
+            &btn_y,
+            &btn_start,
+            &btn_l,
+            &btn_r,
+            &btn_z,
+            &btn_dleft,
+            &btn_dright,
+            &btn_dup,
+            &btn_ddown,
+        );
+
+        // give other tasks a chance to do something
+        yield_now().await;
+
+        // not every loop pass is going to update the stick state
+        match STICK_SIGNAL.try_take() {
+            Some(stick_state) => {
+                gcc_state.stick_x = stick_state.ax;
+                gcc_state.stick_y = stick_state.ay;
+                gcc_state.cstick_x = stick_state.cx;
+                gcc_state.cstick_y = stick_state.cy;
+            }
+            None => (),
+        }
+
+        gcc_publisher.publish_immediate(gcc_state);
+    }
+}
+
+/// Task responsible for updating the stick states.
+/// Publishes the result to STICK_SIGNAL.
+#[embassy_executor::task]
+pub async fn update_stick_states_task(
+    mut spi: Spi<'static, SPI0, embassy_rp::spi::Blocking>,
+    mut spi_acs: Output<'static, AnyPin>,
+    mut spi_ccs: Output<'static, AnyPin>,
+    controller_config: ControllerConfig,
+) {
     let controlstick_params = StickParams::from_stick_config(&controller_config.astick_config);
     let cstick_params = StickParams::from_stick_config(&controller_config.cstick_config);
 
     let filter_gains = FILTER_GAINS.get_normalized_gains(&controller_config);
 
-    let stick_state_fut = async {
     let mut current_stick_state = StickState {
         ax: 127,
         ay: 127,
@@ -439,8 +484,13 @@ pub async fn input_loop(
 
     let mut last_loop_time = Instant::now();
 
+    debug!("Entering stick update loop.");
+
+    // the time at which the current loop iteration should end
+    let mut end_time = Instant::now() + Duration::from_micros(1000);
+
     loop {
-            let timer = Timer::after_micros(1000);
+        let timer = Timer::at(end_time);
 
         current_stick_state = update_stick_states(
             &mut spi,
@@ -460,56 +510,18 @@ pub async fn input_loop(
         .await;
 
         timer.await;
+        end_time += Duration::from_micros(1000);
 
-            match (Instant::now() - last_loop_time).as_micros() {
+        match Instant::now() {
-                a if a > 1100 => {
+            n => {
-                    debug!("Loop took {} us", a);
+                match (n - last_loop_time).as_micros() {
-                }
+                    a if a > 1100 => debug!("Loop took {} us", a),
                     _ => {}
                 };
-
+                last_loop_time = n;
-            last_loop_time = Instant::now();
+            }
+        };
 
         STICK_SIGNAL.signal(current_stick_state.clone());
     }
-    };
-
-    let input_fut = async {
-        loop {
-            let timer = Timer::after_micros(500);
-
-            update_button_states(
-                &mut gcc_state,
-                &btn_a,
-                &btn_b,
-                &btn_x,
-                &btn_y,
-                &btn_start,
-                &btn_l,
-                &btn_r,
-                &btn_z,
-                &btn_dleft,
-                &btn_dright,
-                &btn_dup,
-                &btn_ddown,
-            );
-
-            timer.await;
-
-            // not every loop pass is going to update the stick state
-            match STICK_SIGNAL.try_take() {
-                Some(stick_state) => {
-                    gcc_state.stick_x = stick_state.ax;
-                    gcc_state.stick_y = stick_state.ay;
-                    gcc_state.cstick_x = stick_state.cx;
-                    gcc_state.cstick_y = stick_state.cy;
-                }
-                None => (),
-            }
-
-            GCC_SIGNAL.signal(gcc_state);
-        }
-    };
-
-    join(input_fut, stick_state_fut).await;
 }

src/main.rs

@@ -4,6 +4,7 @@
 
 #![no_std]
 #![no_main]
+mod calibrate;
 mod config;
 mod filter;
 mod gcc_hid;
@@ -11,23 +12,27 @@ mod helpers;
 mod input;
 mod stick;
 
+use calibrate::calibration_loop;
+use config::ControllerConfig;
 use defmt::{debug, info};
 use embassy_executor::Executor;
+use embassy_futures::join::join;
 use embassy_rp::{
     bind_interrupts,
     flash::{Async, Flash},
     gpio::{self, AnyPin, Input},
     multicore::{spawn_core1, Stack},
-    peripherals::USB,
+    peripherals::{SPI0, USB},
     pwm::Pwm,
     spi::{self, Spi},
     usb::{Driver, InterruptHandler},
 };
-use gcc_hid::usb_transfer_loop;
+use gcc_hid::usb_transfer_task;
 use gpio::{Level, Output};
-use input::input_loop;
 
+use input::{update_button_state_task, update_stick_states_task};
 use static_cell::StaticCell;
+
 use {defmt_rtt as _, panic_probe as _};
 
 static mut CORE1_STACK: Stack<4096> = Stack::new();
@@ -49,21 +54,17 @@ fn main() -> ! {
 
     let driver = Driver::new(p.USB, Irqs);
 
+    // reading and writing from flash has to be done on the main thread, else funny things happen.
+
     let mut flash = Flash::<_, Async, FLASH_SIZE>::new(p.FLASH, p.DMA_CH0);
 
     let mut uid = [0u8; 8];
     flash.blocking_unique_id(&mut uid).unwrap();
 
+    let controller_config = ControllerConfig::from_flash_memory(&mut flash).unwrap();
+
     debug!("Read unique id: {:02X}", uid);
 
-    spawn_core1(p.CORE1, unsafe { &mut CORE1_STACK }, move || {
-        let executor1 = EXECUTOR1.init(Executor::new());
-        executor1.run(|spawner| spawner.spawn(usb_transfer_loop(driver, uid)).unwrap());
-    });
-
-    let executor0 = EXECUTOR0.init(Executor::new());
-    info!("Initialized.");
-
     let mosi = p.PIN_7;
     let miso = p.PIN_4;
     let spi_clk = p.PIN_6;
@@ -79,6 +80,33 @@ fn main() -> ! {
     let spi_acs = Output::new(AnyPin::from(p_acs), Level::High); // active low
     let spi_ccs = Output::new(AnyPin::from(p_ccs), Level::High); // active low
 
+    spawn_core1(p.CORE1, unsafe { &mut CORE1_STACK }, move || {
+        let executor1 = EXECUTOR1.init(Executor::new());
+        debug!("Mana");
+        executor1.run(|spawner| {
+            spawner.spawn(usb_transfer_task(driver, uid)).unwrap();
+            spawner
+                .spawn(update_button_state_task(
+                    Input::new(AnyPin::from(p.PIN_20), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_17), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_16), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_11), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_9), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_10), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_8), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_22), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_21), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_18), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_19), gpio::Pull::Up),
+                    Input::new(AnyPin::from(p.PIN_5), gpio::Pull::Up),
+                ))
+                .unwrap()
+        });
+    });
+
+    let executor0 = EXECUTOR0.init(Executor::new());
+    info!("Initialized.");
+
     let mut pwm_config: embassy_rp::pwm::Config = Default::default();
     pwm_config.top = 255;
     pwm_config.enable = true;
@@ -92,25 +120,11 @@ fn main() -> ! {
 
     executor0.run(|spawner| {
         spawner
-            .spawn(input_loop(
+            .spawn(update_stick_states_task(
-                flash,
-                Input::new(AnyPin::from(p.PIN_20), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_17), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_16), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_11), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_9), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_10), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_8), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_22), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_21), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_18), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_19), gpio::Pull::Up),
-                Input::new(AnyPin::from(p.PIN_5), gpio::Pull::Up),
-                // pwm_rumble,
-                // pwm_brake,
                 spi,
                 spi_acs,
                 spi_ccs,
+                controller_config,
             ))
             .unwrap()
     });

src/stick.rs

@@ -570,6 +570,7 @@ fn calc_stick_values(angle: f32) -> (f32, f32) {
     (x, y)
 }
 
+#[link_section = ".time_critical.linearize"]
 pub fn linearize(point: f32, coefficients: &[f32; 4]) -> f32 {
     coefficients[0] * (point * point * point)
         + coefficients[1] * (point * point)
@@ -577,6 +578,7 @@ pub fn linearize(point: f32, coefficients: &[f32; 4]) -> f32 {
         + coefficients[3]
 }
 
+#[link_section = ".time_critical.notch_remap"]
 pub fn notch_remap(
     x_in: f32,
     y_in: f32,