refactor keyboard to 1-count keys so that 0 can indicate no key

firmware/src/keyboard.cpp

@@ -19,10 +19,11 @@ row/col 0 1 2 3
   3     * 0 # D
 */
 
-const char *allKeys = "123A456B789C*0#D";
+const char *allKeys = " 123A456B789C*0#D";
 
-const uint8_t digits[16] =
-  { 1, 2, 3, KEY_NONE,
+const uint8_t digits[17] =
+  { KEY_NONE,
+    1, 2, 3, KEY_NONE,
     4, 5, 6, KEY_NONE,
     7, 8, 9, KEY_NONE,
     KEY_NONE, 0, KEY_NONE, KEY_NONE};
@@ -122,17 +123,15 @@ Key getPressedKey() {
   }
 
   // return key
-  return (rowPressed * 4) + colPressed;
+  return (rowPressed * 4) + colPressed + 1;
 }
 
 uint8_t getPressedDigit(Key key) {
-  if (key == KEY_NONE) return KEY_NONE;
   return digits[key];
 }
 
 Key handleDebugKeyboard(char key) {
-  auto keyboardKey = handleKeyboard();
-  if (keyboardKey != KEY_NONE) {
+  if (auto keyboardKey = handleKeyboard()) {
     return keyboardKey;
   }
 
@@ -146,37 +145,37 @@ Key handleDebugKeyboard(char key) {
   // Backspace -> #
 
   if (key == '1') {
-    return 0;
-  } else if (key == '2') {
     return 1;
-  } else if (key == '3') {
+  } else if (key == '2') {
     return 2;
-  } else if (key == 'a' || key == 'A') {
+  } else if (key == '3') {
     return 3;
-  } else if (key == '4') {
+  } else if (key == 'a' || key == 'A') {
     return 4;
-  } else if (key == '5') {
+  } else if (key == '4') {
     return 5;
-  } else if (key == '6') {
+  } else if (key == '5') {
     return 6;
-  } else if (key == 'b' || key == 'B') {
+  } else if (key == '6') {
     return 7;
-  } else if (key == '7') {
+  } else if (key == 'b' || key == 'B') {
     return 8;
-  } else if (key == '8') {
+  } else if (key == '7') {
     return 9;
-  } else if (key == '9') {
+  } else if (key == '8') {
     return 10;
-  } else if (key == 'c' || key == 'C') {
+  } else if (key == '9') {
     return 11;
-  } else if (key == '*' || key == '.') {
+  } else if (key == 'c' || key == 'C') {
     return 12;
-  } else if (key == '0') {
+  } else if (key == '*' || key == '.') {
     return 13;
-  } else if (key == '#' || (int) key == 8 /* Backspace */) {
+  } else if (key == '0') {
     return 14;
-  } else if (key == 'd' || key == 'D') {
+  } else if (key == '#' || (int) key == 8 /* Backspace */) {
     return 15;
+  } else if (key == 'd' || key == 'D') {
+    return 16;
   }
 
   return KEY_NONE;

firmware/src/keyboard.h

@@ -1,17 +1,19 @@
 #pragma once
 
 /*
-  Keys, in order:
+  Keys, in order (counting from 1):
   123A 456B 789C *0#D
+
+  value 0 indicates no key
  */
 typedef uint8_t Key;
-#define KEY_NONE 255
-#define KEY_A 3
-#define KEY_B 7
-#define KEY_C 11
-#define KEY_D 15
-#define KEY_ASTERISK 12
-#define KEY_HASH 14
+#define KEY_NONE 0
+#define KEY_A 4
+#define KEY_B 8
+#define KEY_C 12
+#define KEY_D 16
+#define KEY_ASTERISK 13
+#define KEY_HASH 15
 
 extern const char *allKeys;
 

firmware/src/main.cpp

@@ -84,8 +84,7 @@ void loop() {
     }
   }
 
-  auto key = handleDebugKeyboard(debugKey);
-  if (key != KEY_NONE) {
+  if (auto key = handleDebugKeyboard(debugKey)) {
     Serial.print("Key pressed: ");
     Serial.print(allKeys[key]);