improve layer switching

Makefile.common

@@ -50,6 +50,7 @@
 
 # List C source files here. (C dependencies are automatically generated.)
 SRC =	tmk.c \
+	layer.c \
 	key_process.c \
 	usb_keyboard.c \
 	usb_mouse.c \
@@ -57,6 +58,7 @@ SRC =	tmk.c \
 	usb.c \
 	jump_bootloader.c \
 	print.c \
+	timer.c \
 	util.c
 SRC +=	$(TARGET_SRC)
 

README

@@ -93,9 +93,6 @@ debouncing logic
     will be coded when bouncing occurs.
     bouncing doesnt occur on my ALPS switch so far.
     scan rate is too slow?(to be measure)
-layer switching
-    time before switching
-    timeout when not used during specific time
 
 Trackpoint(PS/2)
     receive PS/2 signal from TrackPoint
@@ -136,6 +133,9 @@ debug on/off
     key print on/off
     mouse print on/off
     2010/10/26
-
+layer switching
+    time before switching
+    timeout when not used during specific time
+    2010/10/30
 
 EOF

debug.h

@@ -6,7 +6,7 @@
 
 #define debug(s)             if(debug_enable) print(s)
 #define debug_hex(c)         if(debug_enable) phex(c)
-#define debug_hex16(i)       if(debug_enable) phex(i)
+#define debug_hex16(i)       if(debug_enable) phex16(i)
 #define debug_bin(c)         if(debug_enable) pbin(c)
 #define debug_bin_reverse(c) if(debug_enable) pbin_reverse(c)
 

hhkb/controller.h

@@ -3,4 +3,10 @@
 
 #include "controller_teensy.h"
 
+
+/* matrix row size */
+#define MATRIX_ROWS 8
+/* matrix column size */
+#define MATRIX_COLS 8
+
 #endif

hhkb/keymap.c

@@ -6,16 +6,13 @@
 #include <avr/pgmspace.h>
 #include "usb_keyboard.h"
 #include "usb_keycodes.h"
-#include "matrix.h"
 #include "print.h"
 #include "debug.h"
 #include "util.h"
-#include "keymap.h"
+#include "controller.h"
+#include "keymap_skel.h"
 
 
-#define FN_KEYCODE(fn) (pgm_read_byte(&fn_keycode[(fn)]))
-#define FN_LAYER(fn)   (pgm_read_byte(&fn_layer[(fn)]))
-#define KEYCODE(layer, row, col) (pgm_read_byte(&keymaps[(layer)][(row)][(col)]))
 #define KEYMAP( \
     R3C1, R3C0, R0C0, R1C0, R1C1, R2C0, R2C1, R4C0, R4C1, R6C0, R6C1, R7C0, R7C1, R5C0, R5C1, \
     R3C2, R0C1, R0C2, R1C3, R1C2, R2C3, R2C2, R4C2, R4C3, R6C2, R6C3, R7C3, R7C2, R5C2, \
@@ -34,9 +31,7 @@
     { R7C0, R7C1, R7C2, R7C3, R7C4, R7C5, R7C6, KB_NO } \
 }
 
-
+#define KEYCODE(layer, row, col) (pgm_read_byte(&keymaps[(layer)][(row)][(col)]))
-static int current_layer = 0;
-static bool layer_used = false;
 
 
 /* layer to change into while Fn key pressed */ 
@@ -153,76 +148,22 @@ static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 };
 
 
-uint8_t keymap_get_keycode(int row, int col)
+uint8_t keymap_get_keycode(uint8_t layer, uint8_t row, uint8_t col)
 {
-    return keymap_get_keycodel(current_layer, row, col);
+    return KEYCODE(layer, row, col);
 }
 
-uint8_t keymap_get_keycodel(int layer, int row, int col)
+int keymap_fn_layer(uint8_t fn_bits)
 {
-    uint8_t code = KEYCODE(layer, row, col);
+    return pgm_read_byte(&fn_layer[biton(fn_bits)]);
-    // normal key or mouse key
-    if (IS_KEY(code) || IS_MOUSE(code))
-        layer_used = true;
-    return code;
 }
 
-inline
+uint8_t keymap_fn_keycode(uint8_t fn_bits)
-int keymap_get_layer(void)
 {
-    return current_layer;
+    return pgm_read_byte(&fn_keycode[(biton(fn_bits))]);
 }
 
-inline
-int keymap_set_layer(int layer)
-{
-    current_layer = layer;
-    return current_layer;
-}
-
-inline
 bool keymap_is_special_mode(uint8_t fn_bits)
 {
     return (keyboard_modifier_keys == (BIT_LCTRL | BIT_LSHIFT | BIT_LALT | BIT_LGUI));
 }
-
-void keymap_fn_proc(uint8_t fn_bits)
-{
-    // layer switching
-    static uint8_t last_bits = 0;
-    static uint8_t last_mod = 0;
-
-    if (usb_keyboard_has_key() || fn_bits == last_bits) {
-        // do nothing during press other than Fn key 
-        return;
-    } else if (fn_bits == 0) {
-        // send key when Fn key is released without using the layer
-        if (!layer_used) {
-            uint8_t code = FN_KEYCODE(biton(last_bits));
-            if (code != KB_NO) {
-                if (IS_MOD(code)) {
-                    keyboard_modifier_keys = last_mod | 1<<(code & 0x07);
-                } else {
-                    keyboard_keys[0] = code;
-                    keyboard_modifier_keys = last_mod;
-                }
-                usb_keyboard_send();
-                usb_keyboard_print();
-                usb_keyboard_clear();
-            }
-        }
-        last_bits = 0;
-        last_mod = 0;
-        layer_used = false;
-        keymap_set_layer(0); // default layer
-    } else if ((fn_bits & (fn_bits - 1)) == 0) {
-        // switch layer when just one Fn Key is pressed
-        last_bits = fn_bits;
-        last_mod = keyboard_modifier_keys;
-        layer_used = false;
-        keymap_set_layer(FN_LAYER(biton(fn_bits)));
-        debug("layer: "); phex(current_layer); debug("(");
-        debug_bin(last_bits); debug(")\n");
-        debug("last_mod: "); debug_hex(last_mod); debug("\n");
-    }
-}

hhkb/keymap.h

@@ -1,7 +0,0 @@
-#ifndef KEYMAP_H
-#define KEYMAP_H 1
-
-#include "usb_keycodes.h"
-#include "keymap_skel.h"
-
-#endif

hhkb/matrix.c

@@ -5,9 +5,10 @@
 #include <stdbool.h>
 #include <avr/io.h>
 #include <util/delay.h>
-#include "matrix.h"
 #include "print.h"
 #include "util.h"
+#include "controller.h"
+#include "matrix_skel.h"
 
 // matrix is active low. (key on: 0/key off: 1)
 //
@@ -27,8 +28,8 @@
 #define KEY_ON                  ((PINE&(1<<6)) ? false : true)
 
 // matrix state buffer
-uint8_t *matrix;
+static uint8_t *matrix;
-uint8_t *matrix_prev;
+static uint8_t *matrix_prev;
 static uint8_t _matrix0[MATRIX_ROWS];
 static uint8_t _matrix1[MATRIX_ROWS];
 

hhkb/matrix.h

@@ -1,15 +0,0 @@
-#ifndef MATRIX_H
-#define  MATRIX_H 1
-
-#include <stdbool.h>
-#include "matrix_skel.h"
-
-
-#define MATRIX_ROWS 8
-#define MATRIX_COLS 8
-
-
-extern uint8_t *matrix;
-extern uint8_t *matrix_prev;
-
-#endif

key_process.c

@@ -1,17 +1,18 @@
 #include <stdbool.h>
 #include <avr/io.h>
 #include <util/delay.h>
+#include "print.h"
+#include "debug.h"
+#include "timer.h"
+#include "util.h"
+#include "jump_bootloader.h"
 #include "usb_keyboard.h"
 #include "usb_mouse.h"
 #include "usb_keycodes.h"
-#include "print.h"
+#include "layer.h"
-#include "debug.h"
-#include "util.h"
-#include "jump_bootloader.h"
 #include "matrix_skel.h"
 #include "keymap_skel.h"
 #include "controller.h"
-
 #include "key_process.h"
 
 
@@ -61,7 +62,7 @@ void proc_matrix(void) {
         for (int col = 0; col < matrix_cols(); col++) {
             if (!matrix_is_on(row, col)) continue;
 
-            uint8_t code = keymap_get_keycode(row, col);
+            uint8_t code = layer_get_keycode(row, col);
             if (code == KB_NO) {
                 // do nothing
             } else if (IS_MOD(code)) {
@@ -95,11 +96,24 @@ void proc_matrix(void) {
             }
         }
     }
-    keymap_fn_proc(fn_bits);
+    layer_switching(fn_bits);
 
     // when 4 left modifier keys down
     if (keymap_is_special_mode(fn_bits)) {
         switch (keyboard_keys[0]) {
+            case KB_H: // help
+                print_enable = true;
+                print("b: jump to bootloader\n");
+                print("d: debug print toggle\n");
+                print("k: keyboard debug toggle\n");
+                print("m: mouse debug toggle\n");
+                print("x: matrix debug toggle\n");
+                print("v: print version\n");
+                print("t: print timer count\n");
+                print("p: print enable toggle\n");
+                _delay_ms(500);
+                print_enable = false;
+                break;
             case KB_B: // bootloader
                 usb_keyboard_clear();
                 usb_keyboard_send();
@@ -113,8 +127,8 @@ void proc_matrix(void) {
                 usb_keyboard_send();
                 debug_enable = !debug_enable;
                 if (debug_enable) {
-                    print("debug enabled.\n");
                     print_enable = true;
+                    print("debug enabled.\n");
                     debug_matrix = true;
                     debug_keyboard = true;
                     debug_mouse = true;
@@ -160,9 +174,29 @@ void proc_matrix(void) {
             case KB_V: // print version & information
                 usb_keyboard_clear();
                 usb_keyboard_send();
+                print_enable = true;
                 print(STR(DESCRIPTION) "\n");
                 _delay_ms(1000);
                 break;
+            case KB_T: // print timer
+                usb_keyboard_clear();
+                usb_keyboard_send();
+                print_enable = true;
+                print("timer: "); phex16(timer_count); print("\n");
+                _delay_ms(500);
+                break;
+            case KB_P: // print toggle
+                usb_keyboard_clear();
+                usb_keyboard_send();
+                if (print_enable) {
+                    print("print disabled.\n");
+                    print_enable = false;
+                } else {
+                    print_enable = true;
+                    print("print enabled.\n");
+                }
+                _delay_ms(1000);
+                break;
         }
     }
 

keymap_skel.h

@@ -6,13 +6,16 @@
 #include "usb_keycodes.h"
 
 
-uint8_t keymap_get_keycode(int row, int col);
+/* keycode in specific layer */
-uint8_t keymap_get_keycodel(int layer, int row, int col);
+uint8_t keymap_get_keycode(uint8_t layer, uint8_t row, uint8_t col);
-int keymap_get_layer(void);
-int keymap_set_layer(int layer);
 
+/* layer to move during press Fn key */
+int keymap_fn_layer(uint8_t fn_bits);
+
+/* keycode to send when release Fn key without using */
+uint8_t keymap_fn_keycode(uint8_t fn_bits);
+
+/* whether special key combination */
 bool keymap_is_special_mode(uint8_t fn_bits);
-/* process Fn keys. This.should be called every scan. */
-void keymap_fn_proc(uint8_t fn_bits);
 
 #endif

layer.c

@@ -0,0 +1,92 @@
+#include "keymap_skel.h"
+#include "usb_keyboard.h"
+#include "debug.h"
+#include "timer.h"
+#include "layer.h"
+
+/*
+ * LAYER_ENTER_DELAY: prevent from moving new layer
+ *                     press                release
+ * Fn key sate     ____|~~~~~~~~~~~~~~~~~~~|_______________
+ * 
+ * enter_delay         |======|
+ *                              new layer
+ * Layer sw        ___________|~~~~~~~~~~~~|_______________
+ */ 
+#define LAYER_ENTER_DELAY 10
+
+/*
+ * LAYER_SEND_FN_TERM: send keycode if release key in this term
+ *                     press          release(send)
+ * Fn key state    ____|~~~~~~~~~~~~~|_______________
+ *                     press         |       release(not send)
+ * Fn key state    ____|~~~~~~~~~~~~~|~~~~~~|__________
+ *                                   |      |
+ * send_fn_term        |=============o==|   x
+ */
+#define LAYER_SEND_FN_TERM 30
+
+
+static uint8_t current_layer = 0;
+static bool layer_used = false;
+
+
+uint8_t layer_get_keycode(uint8_t row, uint8_t col)
+{
+    uint8_t code = keymap_get_keycode(current_layer, row, col);
+    // normal key or mouse key
+    if ((IS_KEY(code) || IS_MOUSE(code)))
+        layer_used = true;
+    return code;
+}
+
+void layer_switching(uint8_t fn_bits)
+{
+    // layer switching
+    static uint8_t last_bits = 0;
+    static uint8_t last_mod = 0;
+    static uint16_t last_timer = 0; 
+
+    //uint16_t now_timer;
+
+    if (fn_bits == last_bits) {
+        // switch layer when specific time elapsed
+        if (current_layer != keymap_fn_layer(fn_bits) &&
+                timer_elapsed(last_timer) > LAYER_ENTER_DELAY) {
+            current_layer = keymap_fn_layer(fn_bits);
+            debug("time_elapsed: "); debug_hex16(timer_elapsed(last_timer)); debug("\n"); 
+            debug("switch layer: "); debug_hex(current_layer); debug("\n");
+        }
+    } else if (fn_bits == 0) {
+        // send key when Fn key is released without using the layer and within specific time
+        if ((!layer_used || current_layer != keymap_fn_layer(last_bits)) &&
+                timer_elapsed(last_timer) < LAYER_SEND_FN_TERM) {
+            uint8_t code = keymap_fn_keycode(last_bits);
+            if (code != KB_NO) {
+                if (IS_MOD(code)) {
+                    keyboard_modifier_keys = last_mod | MOD_BIT(code);
+                } else {
+                    keyboard_keys[0] = code;
+                    keyboard_modifier_keys = last_mod;
+                }
+                usb_keyboard_send();
+                usb_keyboard_print();
+                usb_keyboard_clear();
+            }
+        }
+        last_bits = 0;
+        last_mod = 0;
+        layer_used = false;
+        current_layer = 0; // default layer
+    } else if ((fn_bits & (fn_bits - 1)) == 0) {
+        // switch layer when just one Fn Key is pressed
+        if (!usb_keyboard_has_key()) {
+            last_bits = fn_bits;
+            last_mod = keyboard_modifier_keys;
+            last_timer = timer_read();
+            debug("last_bits: "); debug_bin(last_bits); debug("\n");
+            debug("last_mod: "); debug_hex(last_mod); debug("\n");
+            debug("last_timer: "); debug_hex16(last_timer); debug("\n");
+        }
+    }
+}

layer.h

@@ -0,0 +1,13 @@
+#ifndef LAYER_H
+#define LAYER_H 1
+
+#include <stdint.h>
+
+
+/* return keycode for switch */
+uint8_t layer_get_keycode(uint8_t row, uint8_t col);
+
+/* process layer switching */
+void layer_switching(uint8_t fn_bits);
+
+#endif

macway/controller.h

@@ -3,4 +3,10 @@
 
 #include "controller_teensy.h"
 
+
+/* matrix row size */
+#define MATRIX_ROWS 9
+/* matrix column size */
+#define MATRIX_COLS 8
+
 #endif

macway/keymap.c

@@ -4,18 +4,16 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <avr/pgmspace.h>
+#include <avr/interrupt.h>
 #include "usb_keyboard.h"
 #include "usb_keycodes.h"
-#include "matrix.h"
 #include "print.h"
 #include "debug.h"
 #include "util.h"
-#include "keymap.h"
+#include "controller.h"
+#include "keymap_skel.h"
 
 
-#define FN_KEYCODE(fn) (pgm_read_byte(&fn_keycode[(fn)]))
-#define FN_LAYER(fn)   (pgm_read_byte(&fn_layer[(fn)]))
-#define KEYCODE(layer, row, col) (pgm_read_byte(&keymaps[(layer)][(row)][(col)]))
 #define KEYMAP( \
     R1C1, R1C0, R2C0, R3C0, R4C0, R4C1, R5C1, R5C0, R6C0, R7C0, R8C0, R8C1, R6C1, R0C2, \
     R1C2, R1C3, R2C3, R3C3, R4C3, R4C2, R5C2, R5C3, R6C3, R7C3, R8C3, R8C2, R6C2, \
@@ -34,14 +32,11 @@
     { R8C0, R8C1,  R8C2,  R8C3,  R8C4, R8C5,  KB_NO, R8C7 } \
 }
 
+#define KEYCODE(layer, row, col) (pgm_read_byte(&keymaps[(layer)][(row)][(col)]))
 
-static int current_layer = 0;
-static bool layer_used = false;
 
-/* layer to change into while Fn key pressed */ 
+static const uint8_t PROGMEM fn_layer[] = { 0, 1, 2, 3, 4, 0, 2, 3 };
-static const int PROGMEM fn_layer[] = { 0, 1, 2, 3, 4, 0, 2, 3 };
 
-/* keycode to sent when Fn key released without using layer keys. */
 static const uint8_t PROGMEM fn_keycode[] = {
     KB_NO,          // FN_0 [NOT USED]
     KB_NO,          // FN_1 layer 1
@@ -73,6 +68,7 @@ static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
            KB_LSFT,KB_Z,   KB_X,   KB_C,   KB_V,   KB_B,   KB_N,   KB_M,   KB_COMM,KB_DOT, KB_SLSH,KB_RSFT,FN_1, \
            FN_7,   KB_LGUI,KB_LALT,KB_SPC, FN_6,   KB_BSLS,KB_GRV, KB_NO,  KB_NO),
 
+
     /* Layer 1: HHKB mode (HHKB Fn)
      * ,-----------------------------------------------------------.
      * |Pow| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delete |
@@ -92,6 +88,7 @@ static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
            KB_LSFT,KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KP_PLUS,KP_MINS,KB_END, KB_PGDN,KB_DOWN,KB_RSFT,FN_1, \
            KB_NO,  KB_LGUI,KB_LALT,KB_SPC, KB_RALT,KB_NO,  KB_NO,  KB_NO,  KB_NO),
 
+
     /* Layer 2: Vi mode (Quote/Rmeta)
      * ,-----------------------------------------------------------.
      * |  `| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|   `   |
@@ -111,6 +108,7 @@ static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
            KB_LSFT,KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_NO,  KB_RSFT,KB_NO, \
            KB_NO,  KB_LGUI,KB_LALT,KB_SPC, FN_6,   KB_NO,  KB_NO,  KB_NO,  KB_NO),
 
+
     /* Layer 3: Mouse mode (Semicolon)
      * ,-------------------------------------------------------- --.
      * |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delete |
@@ -131,6 +129,7 @@ static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
            KB_LSFT,KB_NO,  MS_DOWN,KB_NO,  KB_NO,  KB_NO,  MS_BTN2,MS_BTN1,MS_BTN2,MS_BTN3,KB_NO,  KB_RSFT,KB_NO, \
            FN_7,   KB_LGUI,KB_LALT,MS_BTN1,KB_RALT,KB_NO,  KB_NO,  KB_NO,  KB_NO),
 
+
     /* Layer 4: Matias half keyboard style (Space)
      * ,-----------------------------------------------------------.
      * |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delete |
@@ -152,76 +151,22 @@ static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 };
 
 
-uint8_t keymap_get_keycode(int row, int col)
+uint8_t keymap_get_keycode(uint8_t layer, uint8_t row, uint8_t col)
 {
-    return keymap_get_keycodel(current_layer, row, col);
+    return KEYCODE(layer, row, col);
 }
 
-uint8_t keymap_get_keycodel(int layer, int row, int col)
+int keymap_fn_layer(uint8_t fn_bits)
 {
-    uint8_t code = KEYCODE(layer, row, col);
+    return pgm_read_byte(&fn_layer[biton(fn_bits)]);
-    // normal key or mouse key
-    if (IS_KEY(code) || IS_MOUSE(code))
-        layer_used = true;
-    return code;
 }
 
-inline
+uint8_t keymap_fn_keycode(uint8_t fn_bits)
-int keymap_get_layer(void)
 {
-    return current_layer;
+    return pgm_read_byte(&fn_keycode[(biton(fn_bits))]);
 }
 
-inline
-int keymap_set_layer(int layer)
-{
-    current_layer = layer;
-    return current_layer;
-}
-
-inline
 bool keymap_is_special_mode(uint8_t fn_bits)
 {
     return (keyboard_modifier_keys == (BIT_LCTRL | BIT_LSHIFT | BIT_LALT | BIT_LGUI));
 }
-
-void keymap_fn_proc(uint8_t fn_bits)
-{
-    // layer switching
-    static int last_bits = 0;
-    static uint8_t last_mod = 0;
-
-    if (usb_keyboard_has_key() || fn_bits == last_bits) {
-        // do nothing during press other than Fn key 
-        return;
-    } else if (fn_bits == 0) {
-        // send key when Fn key is released without using the layer
-        if (!layer_used) {
-            uint8_t code = FN_KEYCODE(biton(last_bits));
-            if (code != KB_NO) {
-                if (IS_MOD(code)) {
-                    keyboard_modifier_keys = last_mod | 1<<(code & 0x07);
-                } else {
-                    keyboard_keys[0] = code;
-                    keyboard_modifier_keys = last_mod;
-                }
-                usb_keyboard_send();
-                usb_keyboard_print();
-                usb_keyboard_clear();
-            }
-        }
-        last_bits = 0;
-        last_mod = 0;
-        layer_used = false;
-        keymap_set_layer(0); // default layer
-    } else if ((fn_bits & (fn_bits - 1)) == 0) {
-        // switch layer when just one Fn Key is pressed
-        last_bits = fn_bits;
-        last_mod = keyboard_modifier_keys;
-        layer_used = false;
-        keymap_set_layer(FN_LAYER(biton(fn_bits)));
-        debug("layer: "); phex(current_layer); debug("(");
-        debug_bin(last_bits); debug(")\n");
-        debug("last_mod: "); debug_hex(last_mod); debug("\n");
-    }
-}

macway/keymap.h

@@ -1,7 +0,0 @@
-#ifndef KEYMAP_H
-#define KEYMAP_H 1
-
-#include "usb_keycodes.h"
-#include "keymap_skel.h"
-
-#endif

macway/matrix.c

@@ -5,9 +5,10 @@
 #include <stdbool.h>
 #include <avr/io.h>
 #include <util/delay.h>
-#include "matrix.h"
 #include "print.h"
 #include "util.h"
+#include "controller.h"
+#include "matrix_skel.h"
 
 // matrix is active low. (key on: 0/key off: 1)
 // row: Hi-Z(unselected)/low output(selected)
@@ -16,8 +17,8 @@
 //      PB0-PB7
 
 // matrix state buffer
-uint8_t *matrix;
+static uint8_t *matrix;
-uint8_t *matrix_prev;
+static uint8_t *matrix_prev;
 static uint8_t _matrix0[MATRIX_ROWS];
 static uint8_t _matrix1[MATRIX_ROWS];
 

macway/matrix.h

@@ -1,15 +0,0 @@
-#ifndef MATRIX_H
-#define  MATRIX_H 1
-
-#include <stdint.h>
-#include "matrix_skel.h"
-
-
-#define MATRIX_ROWS 9
-#define MATRIX_COLS 8
-
-
-extern uint8_t *matrix;
-extern uint8_t *matrix_prev;
-
-#endif

timer.c

@@ -0,0 +1,61 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <stdint.h>
+#include "timer.h"
+
+uint16_t timer_count = 0;
+
+// Configure timer 0 to generate a timer overflow interrupt every
+// 256*1024 clock cycles, or approx 61 Hz when using 16 MHz clock
+// This demonstrates how to use interrupts to implement a simple
+// inactivity timeout.
+void timer_init(void)
+{
+    TCCR0A = 0x00;
+    TCCR0B = 0x05;
+    TIMSK0 = (1<<TOIE0);
+}
+
+inline
+void timer_clear(void)
+{
+    cli();
+    timer_count = 0;
+    sei();
+}
+
+inline
+uint16_t timer_read(void)
+{
+    uint8_t _sreg = SREG;
+    uint16_t t;
+
+    cli();
+    t = timer_count;
+    SREG = _sreg;
+
+    return t;
+}
+
+inline
+uint16_t timer_elapsed(uint16_t last)
+{
+    uint8_t _sreg = SREG;
+    uint16_t t;
+
+    cli();
+    t = timer_count;
+    SREG = _sreg;
+
+    return TIMER_DIFF(t, last);
+}
+
+// This interrupt routine is run approx 61 times per second.
+// A very simple inactivity timeout is implemented, where we
+// will send a space character and print a message to the
+// hid_listen debug message window.
+ISR(TIMER0_OVF_vect)
+{
+    timer_count++;
+}
+

timer.h

@@ -0,0 +1,17 @@
+#ifndef TIMER_H
+#define TIMER_H 1
+
+#include <stdint.h>
+
+#define TIMER_DIFF(a, b) ((a) >= (b) ?  (a) - (b) : UINT16_MAX - (b) + (a))
+
+
+extern uint16_t timer_count;
+
+
+void timer_init(void);
+void timer_clear(void);
+uint16_t timer_read(void);
+uint16_t timer_elapsed(uint16_t last);
+
+#endif

tmk.c

@@ -35,17 +35,17 @@
 #include "debug.h"
 #include "util.h"
 #include "controller.h"
+#include "timer.h"
 
 
 #define CPU_PRESCALE(n)    (CLKPR = 0x80, CLKPR = (n))
 
+
 bool debug_enable = false;
 bool debug_matrix = false;
 bool debug_keyboard = false;
 bool debug_mouse = false;
 
-uint16_t idle_count=0;
-
 
 int main(void)
 {
@@ -58,14 +58,7 @@ int main(void)
     usb_init();
     while (!usb_configured()) /* wait */ ;
 
-    // Configure timer 0 to generate a timer overflow interrupt every
+    timer_init();
-    // 256*1024 clock cycles, or approx 61 Hz when using 16 MHz clock
-    // This demonstrates how to use interrupts to implement a simple
-    // inactivity timeout.
-    TCCR0A = 0x00;
-    TCCR0B = 0x05;
-    TIMSK0 = (1<<TOIE0);
-
 
     matrix_init();
     matrix_scan();
@@ -97,13 +90,3 @@ int main(void)
         _delay_ms(2);
     }
 }
-
-
-// This interrupt routine is run approx 61 times per second.
-// A very simple inactivity timeout is implemented, where we
-// will send a space character and print a message to the
-// hid_listen debug message window.
-ISR(TIMER0_OVF_vect)
-{
-    idle_count++;
-}