some simple mouse acceleration

smol_gkos.ino

@@ -3,6 +3,10 @@
 #define TRACKBALL_ADDR		0x0A
 #define TRACKBALL_REG_LEFT	0x04
 
+// using my own masks here since the inbuilt ones conflict with arrow keys etc.
+#define MASK_SHIFT  0x100
+#define MASK_ALTGR  0x200
+
 const byte PIN_A = 33;
 const byte PIN_B = 32;
 const byte PIN_C = 31;
@@ -21,25 +25,24 @@ const byte PIN_LED3 = 3;
 
 const byte PIN_BALL_SDA = 18;
 const byte PIN_BALL_SCL = 19;
-const byte PIN_BALL_INT = 11;
 
 enum Button { A, B, C, D, E, F, MouseUL, MouseUR, MouseDL, MouseDR };
 const int button_pins[10] = {
     PIN_A, PIN_B, PIN_C, PIN_D, PIN_E, PIN_F,
     PIN_MOUSE_UL, PIN_MOUSE_UR, PIN_MOUSE_DL, PIN_MOUSE_DR
 };
-const int debounce_time = 400;
+const int debounce_time = 50;
 int button_timers[10] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
 // different actions that the keyboard can take
-// - print a single character
 // - press (and release) a key
 // - toggle a modifier
-enum ActionType { PrintCharacter, PressKey, ToggleModifier };
+enum ActionType { PressKey, ToggleModifier };
 
-const char button_characters[6] = { 'a', 'b', 'c', 'd', 'e', 'f' };
+const int button_characters[6] = { KEY_A, KEY_B, KEY_C, KEY_D, KEY_E, KEY_F };
-const char button_characters_shifted[6] = { 'A', 'B', 'C', 'D', 'E', 'F' };
+const int button_characters_symbol[6] = {
-const char button_characters_symbol[6] = { '1', '2', '3', '4', '5', '6' };
+    KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6
+};
 
 /*
 backspace, space (keep those two first since they overlap with the rest )
@@ -62,44 +65,27 @@ const byte chord_buttons[24] = {
 const int chord_targets[32] = {
     KEY_BACKSPACE, KEY_LEFT, KEY_LEFT, KEY_HOME,
     KEY_SPACE, KEY_RIGHT, KEY_RIGHT, KEY_END,
-    'g', 'h', 'i', 'j',
+    KEY_G, KEY_H, KEY_I, KEY_J,
-    'k', 'l', 'm', 'n',
+    KEY_K, KEY_L, KEY_M, KEY_N,
-    'o', 'p', 'q', 'r',
+    KEY_O, KEY_P, KEY_Q, KEY_R,
-    's', 't', 'u', 'v',
+    KEY_S, KEY_T, KEY_U, KEY_V,
-    'w', 'x', 'y', 'z',
+    KEY_W, KEY_X, KEY_Y, KEY_Z,
     0, 0, 0, 0
 };
-const int chord_targets_shifted[32] = {
-    KEY_BACKSPACE, KEY_LEFT, KEY_LEFT, KEY_HOME,
-    KEY_SPACE, KEY_RIGHT, KEY_RIGHT, KEY_END,
-    'G', 'H', 'I', 'J',
-    'K', 'L', 'M', 'N',
-    'O', 'P', 'Q', 'R',
-    'S', 'T', 'U', 'V',
-    'W', 'X', 'Y', 'Z',
-    0, 0, 0, 0
-};
-// TODO: check that all the symbols work
-// TODO: match symbols to keypresses in the keyboard layout
 const int chord_targets_symbol[32] = {
     KEY_BACKSPACE, KEY_LEFT, KEY_LEFT, KEY_HOME,
     KEY_SPACE, KEY_RIGHT, KEY_RIGHT, KEY_END,
-    '0', '7', '8', '9',
+    KEY_0, KEY_7, KEY_8, KEY_9,
-    '#', '@', '½', '&',
+//  #              @                       ½                   &
-    '+', '%', '=', '^',
+    KEY_BACKSLASH, KEY_QUOTE + MASK_SHIFT, KEY_5 + MASK_ALTGR, KEY_7 + MASK_SHIFT,
-    '*', '$', '€', '£',
+//  +                       %                   =          ^
-    '(', '[', '<', '{',
+    KEY_EQUAL + MASK_SHIFT, KEY_5 + MASK_SHIFT, KEY_EQUAL, KEY_6 + MASK_SHIFT,
-    ')', ']', '>', '}'
+//  *                   $                   €                   £
-};
+    KEY_8 + MASK_SHIFT, KEY_4 + MASK_SHIFT, KEY_4 + MASK_ALTGR, KEY_3 + MASK_SHIFT,
-const byte chord_target_types[32] = {
+//  (                   [               <                       {
-    1, 1, 1, 1,
+    KEY_9 + MASK_SHIFT, KEY_LEFT_BRACE, KEY_COMMA + MASK_SHIFT, KEY_LEFT_BRACE + MASK_SHIFT,
-    1, 1, 1, 1,
+//  )                   ]                >                        }
-    0, 0, 0, 0,
+    KEY_0 + MASK_SHIFT, KEY_RIGHT_BRACE, KEY_PERIOD + MASK_SHIFT, KEY_RIGHT_BRACE + MASK_SHIFT,
-    0, 0, 0, 0,
-    0, 0, 0, 0,
-    0, 0, 0, 0,
-    0, 0, 0, 0,
-    0, 0, 0, 0
 };
 
 /*
@@ -107,25 +93,34 @@ dash, backslash, slash, apostrophe, comma, exclamation point, question mark,
 period, up, down, page up, page down, shift, symbol shift, switch keyset,
 escape, control, alt, delete, insert, tab, enter
 */
+// TODO: add the middle specials for function keys instead of the weird symbols
 const byte specials[22] = {
     17, 51, 30, 10, 20, 12, 33, 34, 9, 36, 27,
     54, 18, 45, 63, 31, 47, 55, 62, 43, 61, 59
 };
 enum Modifier { Shift, SymbolShift, Keyset, Control, Alt };
 const int special_action_targets[22] = {
-    '-', '\\', '/', '\'', ',', '!', '?', '/', KEY_UP, KEY_DOWN, KEY_PAGE_UP,
+//  -   \   /   '
-    KEY_PAGE_DOWN, Modifier::Shift, Modifier::SymbolShift, Modifier::Keyset,
+    KEY_MINUS, KEY_MINUS + MASK_ALTGR, KEY_SLASH, KEY_QUOTE,
+//  ,   !   ?   .
+    KEY_COMMA, KEY_1 + MASK_SHIFT, KEY_SLASH + MASK_SHIFT, KEY_PERIOD,
+    KEY_UP, KEY_DOWN, KEY_PAGE_UP, KEY_PAGE_DOWN,
+    Modifier::Shift, Modifier::SymbolShift, Modifier::Keyset,
     KEY_ESC, Modifier::Control, Modifier::Alt, KEY_DELETE, KEY_INSERT,
     KEY_TAB, KEY_ENTER
 };
 const int special_action_targets_symbol[22] = {
-    '_', '\`', 0, '\"', ';', '|', '~', ':', 0, 0, 0,
+//  _   `   ´   "
+    KEY_MINUS + MASK_SHIFT, KEY_TILDE, KEY_SEMICOLON + MASK_ALTGR, KEY_2 + MASK_SHIFT,
+//  ;   |   ~   :
+    KEY_SEMICOLON, KEY_TILDE + MASK_ALTGR, KEY_BACKSLASH + MASK_SHIFT, KEY_SEMICOLON + MASK_SHIFT,
     0, 0, 0, 0,
+    0, 0, 0,
     0, 0, 0, 0, 0,
     0, 0
 };
 const byte special_action_target_types[22] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 1, 2, 2, 1, 1, 1, 1
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0
 };
 
 byte key_pressed = 0;
@@ -137,9 +132,29 @@ bool mod_shift = false;
 bool mod_shift_lock = false;
 bool mod_symbol = false;
 bool mod_symbol_lock = false;
-// TODO: control and alt modifiers
 bool mod_control = false;
 bool mod_alt = false;
+bool mod_altgr = false;
+
+IntervalTimer trackball_timer;
+volatile bool trackball_update = false;
+
+byte mouse_up = 0;
+byte mouse_down = 0;
+byte mouse_left = 0;
+byte mouse_right = 0;
+bool mouse_button = false;
+
+const int num_mouse_samples = 10;
+int current_mouse_sample = 0;
+int mouse_movement_sample = 0;
+float mouse_acceleration = 0.0f;
+const float mouse_accel_factor = 0.7f;
+
+const int mouse_scroll_sensitivity = 6;
+int mouse_scroll_dist = 0;
+bool mouse_middle_pressed = false;
+bool mouse_scrolled = false;
 
 void setup() {
     pinMode(PIN_A, INPUT_PULLUP);
@@ -158,35 +173,54 @@ void setup() {
     pinMode(PIN_LED2, OUTPUT);
     pinMode(PIN_LED3, OUTPUT);
 
-    Serial.begin(115200);
+    // poll trackball at 10kHz
-    Serial.println("helo");
+    trackball_timer.begin(trackball_isr, 100);
 
     Wire.begin();
 }
 
 void loop() {
+    /*
+    BUTTONS
+    */
     for (byte b = 0; b < 10; b++) {
         // button is pressed
         if (!digitalRead(button_pins[b])) {
             // increment button timer if it's not full
             if (button_timers[b] < debounce_time)
-            button_timers[b]++;
+                button_timers[b]++;
-            // update pressed gkos keys
+            else {
-            else if (b < 6) {
+                // update pressed gkos keys
-                key_pressed |= 1 << b;
+                if (b < 6) {
-                key_pressed_total |= 1 << b;
+                    key_pressed |= 1 << b;
+                    key_pressed_total |= 1 << b;
+                }
+                // update pressed mouse keys
+                else {
+                    switch (b) {
+                        case Button::MouseUL:
+                            Mouse.press(MOUSE_LEFT);
+                            break;
+                        case Button::MouseUR:
+                            Mouse.press(MOUSE_RIGHT);
+                            break;
+                        case Button::MouseDL:
+                        case Button::MouseDR:
+                            mouse_middle_pressed = true;
+                            break;
+                    }
+                }
             }
         }
         // button is released
         else {
-            // if the button had been debounced, it counts as a keypress
+            // if the button had been debounced, it counts as a press
             if (button_timers[b] >= debounce_time) {
+                // gkos key released
                 if (b < 6) {
                     key_pressed &= ~(1 << b);
-                    // gkos key was released, check if it completed a chord
+                    // check if it completed a chord
-                    // clear temporary modifiers if a keypress was completed
+                    key_released(b);
-                    if (key_released(b))
-                        mod_shift = mod_symbol = mod_control = mod_alt = false;
                     update_leds();
                     if (key_pressed == 0) {
                         key_pressed_total = 0;
@@ -195,14 +229,74 @@ void loop() {
                         chorded_pressed = false;
                     }
                 }
+                // mouse button released
+                else {
+                    switch (b) {
+                        case Button::MouseUL:
+                            Mouse.release(MOUSE_LEFT);
+                            break;
+                        case Button::MouseUR:
+                            Mouse.release(MOUSE_RIGHT);
+                            break;
+                        case Button::MouseDL:
+                        case Button::MouseDR:
+                            if (!mouse_scrolled)
+                                Mouse.click(MOUSE_MIDDLE);
+                            mouse_middle_pressed = mouse_scrolled = false;
+                            mouse_scroll_dist = 0;
+                            break;
+                    }
+                }
             }
             button_timers[b] = 0;
         }
     }
+
+    /*
+    TRACKBALL
+    */
+    noInterrupts();
+    if (trackball_update) {
+        Wire.beginTransmission(TRACKBALL_ADDR);
+        Wire.write(TRACKBALL_REG_LEFT);
+        Wire.endTransmission();
+
+        Wire.requestFrom(TRACKBALL_ADDR, 5);
+        mouse_left = Wire.read();
+        mouse_right = Wire.read();
+        mouse_up = Wire.read();
+        mouse_down = Wire.read();
+        mouse_button = Wire.read();
+
+        int mouse_x = mouse_right - mouse_left;
+        int mouse_y = mouse_down - mouse_up;
+
+        mouse_movement_sample += abs(mouse_x) + abs(mouse_y);
+        current_mouse_sample++;
+        if (current_mouse_sample > num_mouse_samples) {
+            current_mouse_sample = 0;
+            mouse_acceleration = 1.0f + mouse_movement_sample * mouse_accel_factor;
+            mouse_movement_sample = 0;
+        }
+
+        if (mouse_middle_pressed) {
+            mouse_scroll_dist += mouse_y;
+            if (abs(mouse_scroll_dist) > mouse_scroll_sensitivity) {
+                Mouse.scroll(mouse_scroll_dist % mouse_scroll_sensitivity);
+                mouse_scroll_dist %= mouse_scroll_sensitivity;
+                mouse_scrolled = true;
+            }
+        } else {
+            Mouse.move(mouse_x * mouse_acceleration, mouse_y * mouse_acceleration);
+        }
+
+        trackball_update = false;
+    }
+    interrupts();
 }
 
 // returns true if a keypress was completed
-bool key_released(byte key) {
+void key_released(byte key) {
     int target = 0;
 
     /*
@@ -221,7 +315,7 @@ bool key_released(byte key) {
     if (is_special && !chord_used) {
         // only register a special keypress when all keys have been released
         if (key_pressed != 0)
-            return false;
+            return;
 
         target = special_action_targets[special];
         if (mod_shift || mod_shift_lock || mod_symbol || mod_symbol_lock) {
@@ -230,13 +324,9 @@ bool key_released(byte key) {
         }
 
         switch (special_action_target_types[special]) {
-            case ActionType::PrintCharacter:
-                Keyboard.print((char)target);
-                return true;
             case ActionType::PressKey:
-                Keyboard.press(target);
+                press_key(target);
-                Keyboard.release(target);
+                return;
-                return true;
             case ActionType::ToggleModifier:
                 switch (target) {
                     case Modifier::Shift:
@@ -249,24 +339,24 @@ bool key_released(byte key) {
                         } else {
                             mod_shift = true;
                         }
-                        return false;
+                        return;
                     case Modifier::SymbolShift:
                         mod_shift = mod_shift_lock = mod_symbol_lock = false;
                         mod_symbol = !mod_symbol;
-                        return false;
+                        return;
                     case Modifier::Keyset:
                         mod_shift = mod_shift_lock = mod_symbol = false;
                         mod_symbol_lock = !mod_symbol_lock;
-                        return false;
+                        return;
                     case Modifier::Control:
                         mod_control = !mod_control;
-                        return false;
+                        return;
                     case Modifier::Alt:
                         mod_alt = !mod_alt;
-                        return false;
+                        return;
                 }
         }
-        return false;
+        return;
     }
 
     /*
@@ -288,59 +378,78 @@ bool key_released(byte key) {
         if (!chorded_pressed && key_pressed == 0 &&
                 key_pressed_total == chords[chord]) {
             target = chord_targets[chord * 4];
-            if (mod_shift || mod_shift_lock)
+            if (mod_symbol || mod_symbol_lock)
-                target = chord_targets_shifted[chord * 4];
-            else if (mod_symbol || mod_symbol_lock)
                 target = chord_targets_symbol[chord * 4];
 
-            switch (chord_target_types[chord * 4]) {
+            press_key(target);
-                case ActionType::PrintCharacter:
+            return;
-                    Keyboard.print((char)target);
-                    return true;
-                case ActionType::PressKey:
-                    Keyboard.press(target);
-                    Keyboard.release(target);
-                    return true;
-            }
-            return false;
         }
         // keys that can be chorded with
         for (byte b = 0; b < 3; b++) {
             if (key == chord_buttons[chord * 3 + b]) {
                 target = chord_targets[chord * 4 + 1 + b];
-                if (mod_shift || mod_shift_lock)
+                if (mod_symbol || mod_symbol_lock)
-                    target = chord_targets_shifted[chord * 4 + 1 + b];
-                else if (mod_symbol || mod_symbol_lock)
                     target = chord_targets_symbol[chord * 4 + 1 + b];
 
                 // erase key from total so you can hold the chord down for
                 // multiple chorded keypresses
                 key_pressed_total &= ~(1 << key);
                 chorded_pressed = true;
-                switch (chord_target_types[chord * 4 + 1 + b]) {
+                press_key(target);
-                    case ActionType::PrintCharacter:
+                return;
-                        Keyboard.print((char)target);
-                        return true;
-                    case ActionType::PressKey:
-                        Keyboard.press(target);
-                        Keyboard.release(target);
-                        return true;
-                }
             }
         }
-        return false;
+        return;
     }
 
     /*
     REGULAR KEYS
     */
-    if (mod_shift || mod_shift_lock)
+    // keypress
-        Keyboard.print(button_characters_shifted[key]);
+    if (mod_symbol || mod_symbol_lock)
-    else if (mod_symbol || mod_symbol_lock)
+        press_key(button_characters_symbol[key]);
-        Keyboard.print(button_characters_symbol[key]);
     else
-        Keyboard.print(button_characters[key]);
+        press_key(button_characters[key]);
-    return true;
+    return;
+}
+
+void press_key(int key) {
+    // check if modifiers need to be forced
+    if (key & MASK_SHIFT) {
+        mod_shift = true;
+        key &= ~(MASK_SHIFT);
+    }
+    if (key & MASK_ALTGR) {
+        mod_altgr = true;
+        key &= ~(MASK_ALTGR);
+    }
+
+    // modifiers
+    if (mod_shift || mod_shift_lock)
+        Keyboard.press(KEY_LEFT_SHIFT);
+    if (mod_control)
+        Keyboard.press(KEY_LEFT_CTRL);
+    if (mod_alt)
+        Keyboard.press(KEY_LEFT_ALT);
+    if (mod_altgr)
+        Keyboard.press(KEY_RIGHT_ALT);
+
+    // keypress
+    Keyboard.press(key);
+    Keyboard.release(key);
+
+    // release modifiers
+    if (mod_shift || mod_shift_lock)
+        Keyboard.release(KEY_LEFT_SHIFT);
+    if (mod_control)
+        Keyboard.release(KEY_LEFT_CTRL);
+    if (mod_alt)
+        Keyboard.release(KEY_LEFT_ALT);
+    if (mod_altgr)
+        Keyboard.release(KEY_RIGHT_ALT);
+
+    // clear temporary modifiers
+    mod_shift = mod_symbol = mod_control = mod_alt = mod_altgr = false;
 }
 
 void update_leds() {
@@ -348,3 +457,12 @@ void update_leds() {
     digitalWrite(PIN_LED2, mod_symbol || mod_symbol_lock);
     digitalWrite(PIN_LED3, mod_control || mod_alt);
 }
+
+int sign(int num) {
+    if (num >= 0) return 1;
+    return -1;
+}
+
+void trackball_isr() {
+    trackball_update = true;
+}