Fixed debounce issue. Added more filtering for HAT switches

README.md

@@ -96,6 +96,8 @@ Config Layer (holding CONFIG button)
 
 - USB interrupt endpoint configured for 1 ms poll interval (1 kHz reports)
 - Input scan, smoothing, processing, and mapping now execute back-to-back
+- Enhanced button debounce: 15-scan threshold (3ms) with anti-bounce protection to prevent double presses
+- Smart HAT switch filtering: disables all HAT buttons when multiple directions are detected to prevent spurious inputs
 - First activity after idle forces immediate USB packet without waiting for the next tick
 - Existing idle timeout preserved (5 s) to avoid unnecessary host wake-ups
 

rp2040/src/button_matrix.rs

@@ -37,6 +37,9 @@ pub struct ButtonMatrix<'a, const R: usize, const C: usize, const N: usize> {
     pressed: [bool; N],
     debounce: u8,
     debounce_counter: [u8; N],
+    // Anti-bounce protection: minimum time between same-button presses
+    last_press_scan: [u32; N],
+    scan_counter: u32,
 }
 
 impl<'a, const R: usize, const C: usize, const N: usize> ButtonMatrix<'a, R, C, N> {
@@ -57,6 +60,8 @@ impl<'a, const R: usize, const C: usize, const N: usize> ButtonMatrix<'a, R, C,
             pressed: [false; N],
             debounce,
             debounce_counter: [0; N],
+            last_press_scan: [0; N],
+            scan_counter: 0,
         }
     }
 
@@ -78,6 +83,7 @@ impl<'a, const R: usize, const C: usize, const N: usize> ButtonMatrix<'a, R, C,
     /// Arguments
     /// - `delay`: short delay implementation used to let signals settle between columns
     pub fn scan_matrix(&mut self, delay: &mut Delay) {
+        self.scan_counter = self.scan_counter.wrapping_add(1);
         for col_index in 0..self.cols.len() {
             self.cols[col_index].set_low().unwrap();
             delay.delay_us(1);
@@ -103,7 +109,22 @@ impl<'a, const R: usize, const C: usize, const N: usize> ButtonMatrix<'a, R, C,
 
             self.debounce_counter[button_index] += 1;
             if self.debounce_counter[button_index] >= self.debounce {
-                self.pressed[button_index] = current_state;
+                // Anti-bounce protection for press events: minimum 25 scans (5ms) between presses
+                if current_state {
+                    // Pressing
+                    let scans_since_last = self
+                        .scan_counter
+                        .wrapping_sub(self.last_press_scan[button_index]);
+                    if scans_since_last >= 25 {
+                        // 5ms at 200μs scan rate
+                        self.pressed[button_index] = current_state;
+                        self.last_press_scan[button_index] = self.scan_counter;
+                    }
+                } else {
+                    // Releasing
+                    self.pressed[button_index] = current_state;
+                }
+                self.debounce_counter[button_index] = 0;
             }
         }
     }
@@ -112,17 +133,17 @@ impl<'a, const R: usize, const C: usize, const N: usize> ButtonMatrix<'a, R, C,
     ///
     /// For small `N` this copy is cheap. If needed, the API could be extended to
     /// return a reference in the future.
-pub fn buttons_pressed(&mut self) -> [bool; N] {
+    pub fn buttons_pressed(&mut self) -> [bool; N] {
         self.pressed
     }
 }
 
 #[cfg(all(test, feature = "std"))]
 mod tests {
-use super::*;
+    use super::*;
-use core::cell::Cell;
+    use core::cell::Cell;
-use embedded_hal::digital::ErrorType;
+    use embedded_hal::digital::ErrorType;
-use std::rc::Rc;
+    use std::rc::Rc;
 
     struct MockInputPin {
         state: Rc<Cell<bool>>,
@@ -192,7 +213,7 @@ use std::rc::Rc;
         let cols: &'static mut [&'static mut dyn OutputPin<Error = Infallible>; 1] =
             Box::leak(Box::new([col_pin]));
 
-        let matrix = ButtonMatrix::new(rows, cols, 2);
+        let matrix = ButtonMatrix::new(rows, cols, 15);
 
         (matrix, row_state, col_state)
     }
@@ -210,16 +231,34 @@ use std::rc::Rc;
         let (mut matrix, row_state, _col_state) = matrix_fixture();
         let mut states = matrix.buttons_pressed();
         assert!(!states[0]);
+
+        // Set scan counter to start with enough history
+        matrix.scan_counter = 100;
+
         row_state.set(true);
-        matrix.process_column(0);
+        // Need 15 scans to register press
-        matrix.process_column(0);
+        for _ in 0..14 {
+            matrix.scan_counter = matrix.scan_counter.wrapping_add(1);
+            matrix.process_column(0);
+            states = matrix.buttons_pressed();
+            assert!(!states[0]); // Still not pressed
+        }
+        matrix.scan_counter = matrix.scan_counter.wrapping_add(1);
+        matrix.process_column(0); // 15th scan
         states = matrix.buttons_pressed();
-        assert!(states[0]);
+        assert!(states[0]); // Now pressed
 
         row_state.set(false);
-        matrix.process_column(0);
+        // Need 15 scans to register release
-        matrix.process_column(0);
+        for _ in 0..14 {
+            matrix.scan_counter = matrix.scan_counter.wrapping_add(1);
+            matrix.process_column(0);
+            states = matrix.buttons_pressed();
+            assert!(states[0]); // Still pressed
+        }
+        matrix.scan_counter = matrix.scan_counter.wrapping_add(1);
+        matrix.process_column(0); // 15th scan
         states = matrix.buttons_pressed();
-        assert!(!states[0]);
+        assert!(!states[0]); // Now released
     }
 }

rp2040/src/buttons.rs

@@ -98,41 +98,41 @@ impl ButtonManager {
 
     /// Filter HAT switches so only a single direction (or center) can be active.
     pub fn filter_hat_switches(&mut self) {
-        // Filter left hat switch buttons
+        const LEFT_HAT_DIRECTIONS: [usize; 4] = [
-        for i in BUTTON_TOP_LEFT_HAT_UP..=BUTTON_TOP_LEFT_HAT_LEFT {
+            BUTTON_TOP_LEFT_HAT_UP,
-            if (BUTTON_TOP_LEFT_HAT_UP..=BUTTON_TOP_LEFT_HAT_LEFT)
+            BUTTON_TOP_LEFT_HAT_RIGHT,
-                .filter(|&j| j != i)
+            BUTTON_TOP_LEFT_HAT_DOWN,
-                .any(|j| self.buttons[j].pressed)
+            BUTTON_TOP_LEFT_HAT_LEFT,
-            {
+        ];
-                self.buttons[i].pressed = false;
-            }
-        }
 
-        // Fix button state for center hat press on left hat
+        const RIGHT_HAT_DIRECTIONS: [usize; 4] = [
-        if self.buttons[BUTTON_TOP_LEFT_HAT_UP..=BUTTON_TOP_LEFT_HAT_LEFT]
+            BUTTON_TOP_RIGHT_HAT_UP,
+            BUTTON_TOP_RIGHT_HAT_RIGHT,
+            BUTTON_TOP_RIGHT_HAT_DOWN,
+            BUTTON_TOP_RIGHT_HAT_LEFT,
+        ];
+
+        self.reconcile_hat(&LEFT_HAT_DIRECTIONS, BUTTON_TOP_LEFT_HAT);
+        self.reconcile_hat(&RIGHT_HAT_DIRECTIONS, BUTTON_TOP_RIGHT_HAT);
+    }
+
+    fn reconcile_hat(&mut self, directions: &[usize; 4], center: usize) {
+        let pressed_count = directions
             .iter()
-            .any(|b| b.pressed)
+            .filter(|&&index| self.buttons[index].pressed)
-        {
+            .count();
-            self.buttons[BUTTON_TOP_LEFT_HAT].pressed = false;
+
+        if pressed_count == 0 {
+            return;
         }
 
-        // Filter right hat switch buttons
+        self.buttons[center].pressed = false;
-        for i in BUTTON_TOP_RIGHT_HAT_UP..=BUTTON_TOP_RIGHT_HAT_LEFT {
+
-            if (BUTTON_TOP_RIGHT_HAT_UP..=BUTTON_TOP_RIGHT_HAT_LEFT)
+        if pressed_count >= 2 {
-                .filter(|&j| j != i)
+            for &index in directions.iter() {
-                .any(|j| self.buttons[j].pressed)
+                self.buttons[index].pressed = false;
-            {
-                self.buttons[i].pressed = false;
             }
         }
-
-        // Fix button state for center hat press on right hat
-        if self.buttons[BUTTON_TOP_RIGHT_HAT_UP..=BUTTON_TOP_RIGHT_HAT_LEFT]
-            .iter()
-            .any(|b| b.pressed)
-        {
-            self.buttons[BUTTON_TOP_RIGHT_HAT].pressed = false;
-        }
     }
 
     /// Update press types (short/long) and USB change flags; returns whether USB should be updated.
@@ -410,11 +410,12 @@ mod tests {
 
         manager.filter_hat_switches();
 
-        // Only one should remain (implementation filters out conflicting ones)
+        // Multiple directions cancel the hat output completely
         let pressed_count = (BUTTON_TOP_LEFT_HAT_UP..=BUTTON_TOP_LEFT_HAT_LEFT)
             .filter(|&i| manager.buttons[i].pressed)
             .count();
-        assert!(pressed_count <= 1);
+        assert_eq!(pressed_count, 0);
+        assert!(!manager.buttons[BUTTON_TOP_LEFT_HAT].pressed);
     }
 
     #[test]
@@ -427,11 +428,12 @@ mod tests {
 
         manager.filter_hat_switches();
 
-        // Only one should remain (implementation filters out conflicting ones)
+        // Multiple directions cancel the hat output completely
         let pressed_count = (BUTTON_TOP_RIGHT_HAT_UP..=BUTTON_TOP_RIGHT_HAT_LEFT)
             .filter(|&i| manager.buttons[i].pressed)
             .count();
-        assert!(pressed_count <= 1);
+        assert_eq!(pressed_count, 0);
+        assert!(!manager.buttons[BUTTON_TOP_RIGHT_HAT].pressed);
     }
 
     #[test]
@@ -446,6 +448,43 @@ mod tests {
 
         // Center button should be disabled when directional is pressed
         assert!(!manager.buttons[BUTTON_TOP_LEFT_HAT].pressed);
+        // But single direction should remain active
+        assert!(manager.buttons[BUTTON_TOP_LEFT_HAT_UP].pressed);
+    }
+
+    #[test]
+    fn test_hat_switch_single_direction_allowed() {
+        let mut manager = ButtonManager::new();
+
+        // Press only one directional button on left hat
+        manager.buttons[BUTTON_TOP_LEFT_HAT_UP].pressed = true;
+
+        manager.filter_hat_switches();
+
+        // Single direction should remain active
+        assert!(manager.buttons[BUTTON_TOP_LEFT_HAT_UP].pressed);
+
+        // Test same for right hat
+        let mut manager = ButtonManager::new();
+        manager.buttons[BUTTON_TOP_RIGHT_HAT_DOWN].pressed = true;
+
+        manager.filter_hat_switches();
+
+        // Single direction should remain active
+        assert!(manager.buttons[BUTTON_TOP_RIGHT_HAT_DOWN].pressed);
+    }
+
+    #[test]
+    fn test_hat_center_button_works_alone() {
+        let mut manager = ButtonManager::new();
+
+        // Press only center button (no directions)
+        manager.buttons[BUTTON_TOP_LEFT_HAT].pressed = true;
+
+        manager.filter_hat_switches();
+
+        // Center button should remain active when no directions are pressed
+        assert!(manager.buttons[BUTTON_TOP_LEFT_HAT].pressed);
     }
 
     #[test]

rp2040/src/hardware.rs

@@ -27,7 +27,9 @@ pub const AXIS_CENTER: u16 = (ADC_MIN + ADC_MAX) / 2;
 /// Number of physical gimbal axes.
 pub const NBR_OF_GIMBAL_AXIS: usize = 4;
 /// Debounce threshold (in scans) for the matrix.
-pub const DEBOUNCE: u8 = 10;
+/// Increased from 10 to 15 scans to prevent double button presses from bounce.
+/// At 200μs scan rate: 15 scans = 3ms debounce time.
+pub const DEBOUNCE: u8 = 15;
 /// Bytes reserved in EEPROM for calibration data + gimbal mode.
 pub const EEPROM_DATA_LENGTH: usize = 25;
 

rp2040/src/main.rs

@@ -62,8 +62,8 @@ use rp2040_hal::{
 };
 use status::{StatusLed, StatusMode, SystemState};
 use usb_device::class_prelude::*;
-use usb_device::prelude::*;
 use usb_device::device::UsbDeviceState;
+use usb_device::prelude::*;
 use usb_joystick_device::JoystickConfig;
 use usb_report::get_joystick_report;
 use usbd_human_interface_device::prelude::*;

rp2040/src/mapping.rs

@@ -196,7 +196,10 @@ mod tests {
         configure_button_mappings(&mut buttons);
 
         assert_eq!(buttons[BUTTON_TOP_RIGHT_HAT_UP].usb_button, USB_HAT_UP);
-        assert_eq!(buttons[BUTTON_TOP_RIGHT_HAT_RIGHT].usb_button, USB_HAT_RIGHT);
+        assert_eq!(
+            buttons[BUTTON_TOP_RIGHT_HAT_RIGHT].usb_button,
+            USB_HAT_RIGHT
+        );
         assert_eq!(buttons[BUTTON_TOP_RIGHT_HAT_DOWN].usb_button, USB_HAT_DOWN);
         assert_eq!(buttons[BUTTON_TOP_RIGHT_HAT_LEFT].usb_button, USB_HAT_LEFT);
     }