Support "repeat" when a direction button is held down (#1053)

* Support "repeat" when holding a direction button

* Support "repeat" when a direction button is held

* Support "repeat" when a direction button is held

* Support "repeat" when a direction button is held

* Formatting violation - removed a trailing space

* Removed unneeded return() statement

firmware/application/hw/debounce.cpp

@@ -27,11 +27,28 @@
 bool Debounce::feed(const uint8_t bit) {
     history_ = (history_ << 1) | (bit & 1);
 
+    // "Repeat" handling - simulated button release
+    if (repeat_ctr_) {
+        // Make sure the button is still being held continuously
+        if (history_ == 0xFF) {
+            // Simulate button press every REPEAT_SUBSEQUENT_DELAY ticks
+            if (--repeat_ctr_ == 0) {
+                state_ = !state_;
+                repeat_ctr_ = REPEAT_SUBSEQUENT_DELAY / 2;
+                return true;
+            }
+        } else {
+            // It's a real button release; stop simulating
+            repeat_ctr_ = 0;
+        }
+    }
+
     if (state_ == 0) {
         // Previous button state was 0 (released);
         // Has button been held for DEBOUNCE_COUNT ticks?
         if ((history_ & DEBOUNCE_MASK) == DEBOUNCE_MASK) {
             state_ = 1;
+            held_time_ = 0;
             return true;
         }
     } else {
@@ -41,6 +58,21 @@ bool Debounce::feed(const uint8_t bit) {
             state_ = 0;
             return true;
         }
+
+        // Repeat support is limited to the 4 directional buttons
+        if (repeat_enabled_) {
+            // Has button been held continuously for DEBOUNCE_REPEAT_DELAY?
+            if (history_ == 0xFF) {
+                if (++held_time_ == REPEAT_INITIAL_DELAY) {
+                    // Delay reached; trigger repeat code on NEXT tick
+                    repeat_ctr_ = 1;
+                    held_time_ = 0;
+                }
+            } else {
+                // Button not continuously pressed; reset counter
+                held_time_ = 0;
+            }
+        }
     }
     return false;
 }

firmware/application/hw/debounce.hpp

@@ -28,6 +28,10 @@
 #define DEBOUNCE_COUNT 4
 #define DEBOUNCE_MASK ((1 << DEBOUNCE_COUNT) - 1)
 
+// # of timer0 ticks before a held button starts being counted as repeated presses
+#define REPEAT_INITIAL_DELAY 250
+#define REPEAT_SUBSEQUENT_DELAY 92
+
 class Debounce {
    public:
     bool feed(const uint8_t bit);
@@ -36,9 +40,16 @@ class Debounce {
         return state_;
     }
 
+    void enable_repeat() {
+        repeat_enabled_ = true;
+    }
+
    private:
     uint8_t history_{0};
     uint8_t state_{0};
+    bool repeat_enabled_{0};
+    uint16_t repeat_ctr_{0};
+    uint16_t held_time_{0};
 };
 
 #endif /*__DEBOUNCE_H__*/

firmware/application/irq_controls.cpp

@@ -187,6 +187,10 @@ void controls_init() {
      */
     gptStart(&GPTD1, &timer0_config);
     gptStartContinuous(&GPTD1, timer0_match_count);
+
+    // Enable repeat for directional switches only
+    for (size_t i = 0; i < 4; i++)
+        switch_debounce[i].enable_repeat();
 }
 
 SwitchesState get_switches_state() {