Add RFID card scanning off a list of card numbers

firmware/firmware.ino

@@ -6,7 +6,22 @@
 const char* WIFI_SSID = "Protospace";
 const char* WIFI_PASS = "yycmakers";
 char wifiMACAddr[18];
-const String API_ROUTE = String("http://tools-socket.protospace.ca/api/lockout/");
+const String SOCKET_URL = String("http://tools-socket.protospace.ca/api/lockout/");
+const String CARD_URL = String("http://tools-auth.protospace.ca/cards/");
+
+#define CARD_BUFFER_LENGTH 14
+char cardBuffer[CARD_BUFFER_LENGTH];
+
+#define CARD_DATA_LENGTH 10
+#define CARD_CHECK_LENGTH 2
+typedef struct __attribute__((packed)) cardData {
+	char head;
+	char data[CARD_DATA_LENGTH];
+	char checksum[CARD_CHECK_LENGTH];
+	char tail;
+} cardData_t;
+
+String authorizedCards = String("00000C5123,00000D1234,00000C5999,00000C5998,00000C5666");
 
 #define RELAY_PIN D1
 #define GREEN_BUTTON_PIN D3
@@ -23,8 +38,10 @@ const String API_ROUTE = String("http://tools-socket.protospace.ca/api/lockout/"
 
 #define LOGGING true
 
-#define DELAY_TIME 10
-#define COMM_IDLE_TIME 500 / DELAY_TIME
+#define ONE_SECOND 1000
+#define DELAY_TIME ONE_SECOND / 100
+#define COMM_LOCK_IDLE_TIME ONE_SECOND / 2
+#define COMM_CARD_IDLE_TIME ONE_SECOND * 60 * 5
 
 enum wifiStates
 {
@@ -38,7 +55,7 @@ enum lockStates
 	LOCK_OFF,
 	LOCK_PREARM,
 	LOCK_ARMED,
-	LOCK_ON_PRESSED,
+	LOCK_ON_PRESSED, // to wait until button is released
 	LOCK_ON,
 } lockState = LOCK_OFF;
 
@@ -46,12 +63,13 @@ enum commStates
 {
 	COMM_INIT,
 	COMM_IDLE,
-	COMM_SEND,
+	COMM_GET_LOCK,
+	COMM_GET_CARD,
 } commState = COMM_INIT;
 
 void setup()
 {
-	if (LOGGING) Serial.begin(115200);
+	Serial.begin(9600);
 	if (LOGGING) Serial.println("[INFO] Serial started.");
 
 	pinMode(RELAY_PIN, OUTPUT);
@@ -67,14 +85,88 @@ void loop()
 	processLockState();
 	processCommState();
 
+	if (Serial.available() >= CARD_BUFFER_LENGTH) {
+		uint8_t bufPos = 0;
+
+		while (true) {
+			char readChar = Serial.read();
+
+			if (readChar == -1) {
+				break;
+			} else if (readChar == 0x2) {
+				bufPos = 0;
+			}
+
+			if (bufPos >= CARD_BUFFER_LENGTH) {
+				break;
+			}
+
+			cardBuffer[bufPos++] = readChar;
+
+			if (readChar == 0x3 && bufPos == CARD_BUFFER_LENGTH) {
+				checkCard();
+				break;
+			}
+		}
+	}
+
 	delay(DELAY_TIME);
 }
 
+int8_t charToNum(char input) {
+	return String("0123456789ABCDEF").indexOf(input);
+}
+
+bool checksum(cardData_t *cardData) {
+	// checksum is each hex data byte xord'd together.
+	// each char is a hex nibble, so we have to work in pairs.
+
+	int8_t even = 0, odd = 0;
+
+	for (int i = 0; i < CARD_DATA_LENGTH; i++) {
+		int8_t num = charToNum(cardData->data[i]);
+
+		if (num == -1) return false;
+		if (i % 2 == 0) even ^= num;
+		if (i % 2 == 1) odd ^= num;
+	}
+
+	int8_t checksum_even = charToNum(cardData->checksum[0]);
+	int8_t checksum_odd = charToNum(cardData->checksum[1]);
+
+	if (even == checksum_even && odd == checksum_odd) {
+		return true;
+	} else {
+		return false;
+	}
+}
+
+void checkCard() {
+	cardData_t *cardData = (cardData_t *) cardBuffer;
+
+	if (cardData->head == 0x2 && cardData->tail == 0x3 && checksum(cardData)) {
+		String cardStr = String();
+
+		for (int i = 0; i < CARD_DATA_LENGTH; i++)
+			cardStr += cardData->data[i];
+
+		if (LOGGING) Serial.println("[INFO] Good scan from card: " + cardStr);
+
+		if (authorizedCards.indexOf(cardStr) >= 0) {
+			if (LOGGING) Serial.println("[INFO] Card is authorized on machine.");
+			if (lockState == LOCK_OFF) {
+				lockState = LOCK_PREARM;
+			}
+		} else {
+			if (LOGGING) Serial.println("[INFO] Card not authorized or machine.");
+		}
+	}
+}
+
 void processWifiState()
 {
 	switch(wifiState) {
 		case WIFI_DISCONNECTED:
-			lockState = LOCK_OFF;
 			commState = COMM_INIT;
 
 			if (LOGGING) Serial.println("[INFO] Wifi is disconnected. Attempting to connect...");
@@ -83,7 +175,6 @@ void processWifiState()
 			wifiState = WIFI_CONNECTING;
 			break;
 		case WIFI_CONNECTING:
-			lockState = LOCK_OFF;
 			commState = COMM_INIT;
 
 			if (WiFi.status() == WL_CONNECTED) {
@@ -148,7 +239,7 @@ void processLockState()
 
 			if (redButton()) {
 				if (LOGGING) Serial.println("[INFO] Unarming interlock.");
-				lockState = LOCK_OFF_PRESSED;
+				lockState = LOCK_OFF;
 			} else if (greenButton()) {
 				if (LOGGING) Serial.println("[INFO] On button pressed.");
 				lockState = LOCK_ON_PRESSED;
@@ -157,7 +248,7 @@ void processLockState()
 		case LOCK_ON_PRESSED:
 			if (redButton()) {
 				if (LOGGING) Serial.println("[ERROR] Off button pressed, aborting.");
-				lockState = LOCK_OFF_PRESSED;
+				lockState = LOCK_OFF;
 			} else if (!greenButton()) {
 				if (LOGGING) Serial.println("[INFO] Turning machine on.");
 				lockState = LOCK_ON;
@@ -182,20 +273,20 @@ void processLockState()
 }
 
 // JSON functions to prevent memory leaking
-String serializeJson(int lockState) {
+String serializeLockJson(uint8_t lockState) {
 	// Generated with: https://arduinojson.org/assistant/
 	const size_t bufferSize = JSON_OBJECT_SIZE(1) + 50;
 	DynamicJsonBuffer jsonBuffer(bufferSize);
 
 	JsonObject& root = jsonBuffer.createObject();
-	root["lockState"] = (int) lockState;
+	root["lockState"] = (uint8_t) lockState;
 	String postData = String();
 	root.printTo(postData);
 
 	return postData;
 }
 
-String deserializeJson(String input) {
+String deserializeLockJson(String input) {
 	// Generated with: https://arduinojson.org/assistant/
 	const size_t bufferSize = JSON_OBJECT_SIZE(1) + 50;
 	DynamicJsonBuffer jsonBuffer(bufferSize);
@@ -208,30 +299,37 @@ String deserializeJson(String input) {
 
 void processCommState()
 {
-	static int commIdleCount = 0;
+	static uint16_t commLockIdleCount = 0;
+	static uint16_t commCardIdleCount = 0;
 
 	switch (commState) {
 		case COMM_INIT:
-			commIdleCount = 0;
+			commLockIdleCount = 0;
+			commCardIdleCount = 0;
+
 			commState = COMM_IDLE;
 			break;
 		case COMM_IDLE:
-			commIdleCount++;
-			if (commIdleCount >= COMM_IDLE_TIME) {
-				commState = COMM_SEND;
+			commLockIdleCount++;
+			commCardIdleCount++;
+
+			if (commLockIdleCount >= COMM_LOCK_IDLE_TIME / DELAY_TIME) {
+				commState = COMM_GET_LOCK;
+			} else if (commCardIdleCount >= COMM_CARD_IDLE_TIME / DELAY_TIME) {
+				commState = COMM_GET_CARD;
 			}
 			break;
-		case COMM_SEND:
-			if (LOGGING) Serial.println("[INFO] HTTP begin.");
+		case COMM_GET_LOCK:
+			if (LOGGING) Serial.println("[INFO] Lock state HTTP begin.");
 			HTTPClient http;
 			//http.begin("https://url", "7a 9c f4 db 40 d3 62 5a 6e 21 bc 5c cc 66 c8 3e a1 45 59 38"); //HTTPS
-			http.begin(API_ROUTE + wifiMACAddr);
+			http.begin(SOCKET_URL + wifiMACAddr);
 			http.addHeader("Content-Type", "application/json");
 
 			if (LOGGING) Serial.print("[INFO] HTTP POST: ");
-			String postData = serializeJson(lockState);
+			String postData = serializeLockJson(lockState);
 			if (LOGGING) Serial.println(postData);
-			int httpCode = http.POST(postData);
+			uint16_t httpCode = http.POST(postData);
 
 			if (httpCode > 0) {
 				if (LOGGING) Serial.printf("[INFO] POST success, code: %d\n", httpCode);
@@ -240,10 +338,10 @@ void processCommState()
 					if (LOGGING) Serial.print("[INFO] Resource found, parsing response: ");
 					String payload = http.getString();
 					if (LOGGING) Serial.println(payload);
-					String action = deserializeJson(payload);
+					String action = deserializeLockJson(payload);
 
 					if (action == "arm"  && lockState == LOCK_OFF) {
-						lockState = LOCK_PREARMED;
+						lockState = LOCK_PREARM;
 					} else if (action == "disarm") {
 						lockState = LOCK_OFF;
 					}
@@ -256,7 +354,9 @@ void processCommState()
 				if (LOGGING) Serial.printf("[ERROR] POST failed, error: %s\n", http.errorToString(httpCode).c_str());
 			}
 
-			commState = COMM_INIT;
+			commLockIdleCount = 0;
+
+			commState = COMM_IDLE;
 			break;
 	}
 }