From 5b409b1da5a287b05a4bb2e21381065316e10bd2 Mon Sep 17 00:00:00 2001
From: Jesse Vincent <jesse@keyboard.io>
Date: Wed, 25 Sep 2019 22:31:36 -0700
Subject: [PATCH] Move the keyscanner into the interrupt. This gets us a much
 more stable keyscan rate, which makes debouncing more accurate.

Signed-off-by: Jesse Vincent <jesse@keyboard.io>
---
 src/kaleidoscope/hardware/ATMegaKeyboard.cpp |  6 ------
 src/kaleidoscope/hardware/ATMegaKeyboard.h   | 11 +++++------
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/kaleidoscope/hardware/ATMegaKeyboard.cpp b/src/kaleidoscope/hardware/ATMegaKeyboard.cpp
index dcfe4681..c6aac7d5 100644
--- a/src/kaleidoscope/hardware/ATMegaKeyboard.cpp
+++ b/src/kaleidoscope/hardware/ATMegaKeyboard.cpp
@@ -24,7 +24,6 @@
 namespace kaleidoscope {
 namespace hardware {
 
-bool ATMegaKeyboard::do_scan_;
 uint8_t ATMegaKeyboard::debounce = 3;
 
 void ATMegaKeyboard::setup(void) {
@@ -97,11 +96,6 @@ void __attribute__((optimize(3))) ATMegaKeyboard::actOnMatrixScan() {
 }
 
 void ATMegaKeyboard::scanMatrix() {
-  if (do_scan_) {
-    do_scan_ = false;
-    // We only want to update our matrix if the timer has expired.
-    KeyboardHardware.readMatrix();
-  }
   // We ALWAYS want to tell Kaleidoscope about the state of the matrix
   KeyboardHardware.actOnMatrixScan();
 }
diff --git a/src/kaleidoscope/hardware/ATMegaKeyboard.h b/src/kaleidoscope/hardware/ATMegaKeyboard.h
index cba751c0..5637dce4 100644
--- a/src/kaleidoscope/hardware/ATMegaKeyboard.h
+++ b/src/kaleidoscope/hardware/ATMegaKeyboard.h
@@ -113,9 +113,9 @@ struct cRGB {
   typedef MatrixAddr<NUM_ARGS(ROW_PINS_), NUM_ARGS(COL_PINS_)> KeyAddr;  \
                                                                          \
   static uint16_t previousKeyState_[matrix_rows];                        \
-  static uint16_t keyState_[matrix_rows];                                \
+  static volatile uint16_t keyState_[matrix_rows];                                \
   static uint16_t masks_[matrix_rows];                                   \
-  static uint8_t debounce_matrix_[matrix_rows][matrix_columns];          \
+  static volatile uint8_t debounce_matrix_[matrix_rows][matrix_columns];          \
                                                                          \
   ATMEGA_KEYBOARD_MATRIX_ACCESS_METHODS
 
@@ -125,12 +125,12 @@ struct cRGB {
   constexpr uint8_t BOARD::matrix_row_pins[matrix_rows];        \
   constexpr uint8_t BOARD::matrix_col_pins[matrix_columns];     \
   uint16_t BOARD::previousKeyState_[matrix_rows];               \
-  uint16_t BOARD::keyState_[matrix_rows];                       \
+  volatile uint16_t BOARD::keyState_[matrix_rows];                       \
   uint16_t BOARD::masks_[matrix_rows];                          \
-  uint8_t BOARD::debounce_matrix_[matrix_rows][matrix_columns]; \
+  volatile uint8_t BOARD::debounce_matrix_[matrix_rows][matrix_columns]; \
                                                                 \
   ISR(TIMER1_OVF_vect) {                                        \
-    BOARD::do_scan_ = true;                                     \
+    KeyboardHardware.readMatrix();				\
   }
 
 namespace kaleidoscope {
@@ -150,7 +150,6 @@ class ATMegaKeyboard : public kaleidoscope::Hardware {
 
   uint8_t previousPressedKeyswitchCount();
 
-  static bool do_scan_;
 
  protected:
   kaleidoscope::driver::mcu::ATMega32U4 mcu_;