Encoder rotation rate multiplier support (#1876)

firmware/application/hw/debounce.cpp

@@ -24,6 +24,9 @@
 
 #include "utility.hpp"
 
+#include "portapack.hpp"
+#include "portapack_persistent_memory.hpp"
+
 uint8_t Debounce::state() {
     uint8_t v = state_to_report_;
     simulated_pulse_ = false;
@@ -154,6 +157,10 @@ uint8_t EncoderDebounce::state() {
     return state_;
 }
 
+uint8_t EncoderDebounce::rotation_rate() {
+    return last_rotation_rate_;
+}
+
 // Returns TRUE if encoder position phase bits changed (after debouncing)
 bool EncoderDebounce::feed(const uint8_t phase_bits) {
     history_ = (history_ << 2) | phase_bits;
@@ -164,14 +171,21 @@ bool EncoderDebounce::feed(const uint8_t phase_bits) {
     // But, checking for equal seems to cause issues with at least 1 user's encoder, so we're treating the input
     // as "stable" if at least ONE input bit is consistent for 4 ticks...
     uint8_t diff = (history_ ^ expected_stable_history);
-    if ((diff == 0) || ((diff & 0b01010101) == 0) || ((diff & 0b10101010) == 0)) {
+    if (((diff & 0b01010101) == 0) || ((diff & 0b10101010) == 0)) {
         // Has the debounced input value changed?
         if (state_ != phase_bits) {
             state_ = phase_bits;
+
+            // Rate multiplier is for larger delta increments when dial is rotated rapidly.
+            last_rotation_rate_ = rotation_rate_downcounter_;
+            rotation_rate_downcounter_ = portapack::persistent_memory::encoder_rate_multiplier();
             return true;
         }
     }
 
-    // Unstable input, or no change
+    // Unstable input, or no change.
+    // Decrement rotation rate detector once per timer tick.
+    if (rotation_rate_downcounter_ > 1)
+        rotation_rate_downcounter_--;
     return false;
 }

firmware/application/hw/debounce.hpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
+ * Copyright (C) 2024 Mark Thompson
  *
  * This file is part of PortaPack.
  *
@@ -70,10 +71,15 @@ class EncoderDebounce {
 
     uint8_t state();  // returns debounced phase bits from encoder
 
+    uint8_t rotation_rate();  // returns last rotation rate
+
    private:
     uint8_t history_{0};  // shift register of previous reads from encoder
 
     uint8_t state_{0};  // actual encoder output state (after debounce logic)
+
+    uint8_t last_rotation_rate_{1};
+    uint8_t rotation_rate_downcounter_{1};  // down-counter to estimate rotation speed
 };
 
 #endif /*__DEBOUNCE_H__*/

firmware/application/hw/encoder.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
+ * Copyright (C) 2024 Mark Thompson
  *
  * This file is part of PortaPack.
  *
@@ -63,7 +64,7 @@ int_fast8_t Encoder::update(const uint_fast8_t phase_bits) {
 
     // Require 2 state changes in same direction to register movement -- for additional level of contact switch debouncing
     if (direction == prev_direction) {
-        if ((sensitivity_map[portapack::persistent_memory::config_encoder_dial_sensitivity()] & (1 << state)) == 0)
+        if ((sensitivity_map[portapack::persistent_memory::encoder_dial_sensitivity()] & (1 << state)) == 0)
             return 0;
         return direction;
     }

firmware/application/hw/encoder.hpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
+ * Copyright (C) 2024 Mark Thompson
  *
  * This file is part of PortaPack.
  *