Payphone/Implementation

<code> static const uint8_t D0 = 16; static const uint8_t D1 = 5; static const uint8_t D2 = 4; static const uint8_t D3 = 0; static const uint8_t D4 = 2; static const uint8_t D5 = 14; static const uint8_t D6 = 12; static const uint8_t D7 = 13; static const uint8_t D8 = 15; const int rowPin0 = D0; //const int rowPin0 = 16; const int rowPin1 = D1; //const int rowPin1 = 5; const int rowPin2 = D2; //const int rowPin2 = 4; const int rowPin3 = D3; //const int rowPin3 = 0; const int columnPin0 = D4; //const int columnPin0 = 2; const int columnPin1 = D5; //const int columnPin1 = 14; const int columnPin2 = D6; //const int columnPin2 = 12; const int strikePin = D7; //const int strikePin = 13; const int tonePin = D8; const int columns[] = { columnPin0, columnPin1, columnPin2 }; const int rows[] = { rowPin0, rowPin1, rowPin2, rowPin3 }; char keys[][12] = { "zero.", "one.", "two.", "three.", "four.", "five.", "six.", "seven.", "eight.", "nine.", "star.", "pound." }; // int tones[12] = { 1209, 1336, 1477 } int freq = 880; const int matrix[4][3] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 11 }; const int rowIdentityMatrix[4][4] = { LOW, HIGH, HIGH, HIGH, HIGH, LOW, HIGH, HIGH, HIGH, HIGH, LOW, HIGH, HIGH, HIGH, HIGH, LOW }; int canRegisterKeyPress[4][3] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }; int pinCodeRingBuffer[4]; int currentPinIndex = 0; void setup() { Serial.begin(115200); Serial.println("Hello World"); resetPinCode(); pinMode(strikePin, OUTPUT); pinMode(columnPin0, INPUT_PULLUP); pinMode(columnPin1, INPUT_PULLUP); pinMode(columnPin2, INPUT_PULLUP); pinMode(rowPin0, OUTPUT); pinMode(rowPin1, OUTPUT); pinMode(rowPin2, OUTPUT); pinMode(rowPin3, OUTPUT); digitalWrite(rowPin0, HIGH); digitalWrite(rowPin1, HIGH); digitalWrite(rowPin2, HIGH); digitalWrite(rowPin3, HIGH); digitalWrite(strikePin, LOW); } void loop() { gateKeep(getCurrentKey()); } int getCurrentKey() { int currentPressedKey = -1; for (int r = 0; r < 4; r++) { for (int i = 0; i < 4; i++) { digitalWrite(rows[i], rowIdentityMatrix[r][i]); } delay(2); for (int c = 0; c < 3; c++) { const bool pressingKey = digitalRead(columns[c]) == LOW; if (pressingKey && canRegisterKeyPress[r][c]) { canRegisterKeyPress[r][c] = false; currentPressedKey = matrix[r][c]; Serial.println(currentPressedKey); tone(tonePin, freq); } else if (!pressingKey) { canRegisterKeyPress[r][c] = true; } delay(2); } } return currentPressedKey; } void gateKeep(int key) { if (key >= 0) { Serial.println(key); updateRingBuffer(key); maybeStrikeIt(); noTone(tonePin); } } void updateRingBuffer(int key) { pinCodeRingBuffer[currentPinIndex] = key; currentPinIndex = (currentPinIndex + 1) % 4; } void maybeStrikeIt() { //    const int code[] = { 1, 8, 4, 8 }; const int code[] = { 2, 6, 0, 0 }; // Check if the strike should strike out for (int i = 0; i < 4; i++) { bool isValidMatch = true; for (int j = 0; j < 4; j++) { if (pinCodeRingBuffer[(i + j) % 4] != code[j]) { isValidMatch = false; break; } } if (isValidMatch) { grantEntryAccess(); break; } } } void grantEntryAccess() { Serial.println("Door is opening"); reallyStrikeIt(); } void reallyStrikeIt() { digitalWrite(strikePin, HIGH); delay(2500); digitalWrite(strikePin, LOW); for (int i = 0; i < 2; i++) { digitalWrite(strikePin, HIGH); delay(250); digitalWrite(strikePin, LOW); delay(250); } resetPinCode(); } void resetPinCode() { pinCodeRingBuffer[0] = pinCodeRingBuffer[1] = pinCodeRingBuffer[2] = pinCodeRingBuffer[3] = 99; } </code>