implemented queue

solarpump/mp3.ino

@@ -3,37 +3,58 @@
 
 static SoftwareSerial mp3(MP3RX, MP3TX);
 
+// the queue for playing sounds
 #define QUEUESIZE 16
 static uint8_t fileQueue[QUEUESIZE];
-static uint8_t currentPlayPos = 0;  // fileQueue[currentPlayPos] is currently played
-static uint8_t currentQueueEnd = 0;  // fileQueue[currentQueue] is the next free place in the queue
 
+// needs to be run once at the start
 void mp3Setup(void) {
 	mp3.begin(4800);
 	pinMode(MP3BUSY, INPUT_PULLUP);
 	//mp3.sendCommand(CMD_SEL_DEV, 0, 2); //select sd-card
 }
 
+// immediately play a file, ignoring any queue or BUSY pin
 void playFile(uint8_t fileNumber) {
 	mp3.write(fileNumber);
 }
 
 // play next file in queue if device is not busy anymore
+// this should be constantly run in the loop-function
 void mp3Loop(void) {
-	// only do things if we were just playing a file
-	// and we are not busy
-	if (fileQueue[currentPlayPos] == 0) {
-		Serial.print("No file was being played at pos ");
-		Serial.println(currentPlayPos);
+	/*
+	 * the BUSY pin does not react immediately
+	 * waitForBusy gets set to true when we play a file
+	 * after that we wait until the BUSY pin reacts and becomes LOW
+	 * now we can wait for the flank from LOW to HIGH => then the playing is done
+	 */
+	static bool waitForBusy = false;
+	// next playing position in the queue
+	static uint8_t currentPlayPos = 0;
+
+	// check if we are busy
+	if (digitalRead(MP3BUSY) == LOW) {
+		// we are done waiting for the BUSY pin
+		waitForBusy = false;
 		return;
 	}
-	if (digitalRead(MP3BUSY) == LOW) {
-		Serial.println("mp3 still busy");
+
+	/*
+	 * BUSY pin is HIGH => we are not busy
+	 * if waytForBusy == true, then we have just started playing a file,
+	 * and we know that soon BUSY pin will be LOW
+	 * if fileQueue[currentPlayPos] == 0, then there is no file in the queue
+	 */
+	if (waitForBusy || fileQueue[currentPlayPos] == 0) {
 		return;
 	}
 
-	Serial.print("Emptying at playpos ");
-	Serial.println(currentPlayPos);
+	// play the file at the current queue position
+	mp3.write(fileQueue[currentPlayPos]);
+	// see explanation above
+	waitForBusy = true;
+
+	// file can be removed off the queue
 	fileQueue[currentPlayPos] = 0;
 
 	// advance one position further
@@ -42,36 +63,22 @@ void mp3Loop(void) {
 	if (currentPlayPos == QUEUESIZE) {
 		currentPlayPos = 0;
 	}
-	Serial.print("new playpos ");
-	Serial.println(currentPlayPos);
-
-	// here is no file to play?
-	if (fileQueue[currentPlayPos] == 0) {
-		Serial.println("There is no file to play here");
-		return;
-	}
-
-	Serial.print("Playing file ");
-	Serial.print(fileQueue[currentPlayPos]);
-	Serial.print(" at playpos ");
-	Serial.println(currentPlayPos);
-	mp3.write(fileQueue[currentPlayPos]);
 }
 
-// add file to the queue and play start playing the queue
+// add a file to the queue and start playing the queue
 void playFileQueue(uint8_t fileNumber) {
-	Serial.print("Adding ");
-	Serial.print(fileNumber);
-	Serial.print(" to queue at pos ");
-	Serial.println(currentQueueEnd);
+	// position of end of queue
+	static uint8_t currentQueueEnd = 0;
+	// save file to queue
 	fileQueue[currentQueueEnd] = fileNumber;
+
 	// the end is now one pos further
 	++currentQueueEnd;
 	// in case of wraparound
 	if (currentQueueEnd == QUEUESIZE) {
 		currentQueueEnd = 0;
 	}
-	Serial.print("New queue end at pos ");
-	Serial.println(currentQueueEnd);
+
+	// start playing the queue if it is not playing already
 	mp3Loop();
 }

solarpump/solarpump.ino

@@ -163,10 +163,9 @@ void loop(void) {
 
 	if (checkButton() == LOW) {
 		displayLight(true);
-		Serial.println("Adding temperature to queue");
 		playFileQueue(SOUND_TEMPERATURE);
-		Serial.println("Adding höchstwert to queue");
 		playFileQueue(SOUND_HOCHSTER_WERT);
+		playFileQueue(SOUND_KOMMA);
 	} else {
 		displayLight(false);
 	}