Photon Audio Example

main.ino

#define MICROPHONE_PIN A5
#define AUDIO_BUFFER_MAX 8192

int audioStartIdx = 0, audioEndIdx = 0;
uint16_t audioBuffer[AUDIO_BUFFER_MAX];
uint16_t txBuffer[AUDIO_BUFFER_MAX];

// version without timers
unsigned long lastRead = micros();
char myIpAddress[24];

TCPClient audioClient;
TCPClient checkClient;
TCPServer audioServer = TCPServer(3443);

void setup() {
    Serial.begin(115200);
    pinMode(MICROPHONE_PIN, INPUT);
    
    // so we know where to connect, try:
    // particle get MY_DEVICE_NAME ipAddress
    
    Spark.variable("ipAddress", myIpAddress, STRING);
    IPAddress myIp = WiFi.localIP();
    sprintf(myIpAddress, "%d.%d.%d.%d", myIp[0], myIp[1], myIp[2], myIp[3]);
    
    
    // 1/8000th of a second is 125 microseconds
    audioServer.begin();
    
    lastRead = micros();
}

void loop() {
    checkClient = audioServer.available();
    if (checkClient.connected()) {
        audioClient = checkClient; 
    }
    
    //listen for 100ms, taking a sample every 125us,
    //and then send that chunk over the network.
    listenAndSend(100);
}

void listenAndSend(int delay) {
    unsigned long startedListening = millis();
    
    while ((millis() - startedListening) < delay) {
        unsigned long time = micros();
        
        if (lastRead > time) {
            // time wrapped?
            //lets just skip a beat for now, whatever.
            lastRead = time;
        }
        
        //125 microseconds is 1/8000th of a second
        if ((time - lastRead) > 125) {
            lastRead = time;
            readMic();
        }
    }
    sendAudio();
}

 
// Callback for Timer 1
void readMic(void) {
    uint16_t value = analogRead(MICROPHONE_PIN);
    if (audioEndIdx >= AUDIO_BUFFER_MAX) {
        audioEndIdx = 0;
    }
    audioBuffer[audioEndIdx++] = value;
}

void copyAudio(uint16_t *bufferPtr) {
    //if end is after start, read from start->end
    //if end is before start, then we wrapped, read from start->max, 0->end
    
    int endSnapshotIdx = audioEndIdx;
    bool wrapped = endSnapshotIdx < audioStartIdx;
    int endIdx = (wrapped) ? AUDIO_BUFFER_MAX : endSnapshotIdx;
    int c = 0;
    
    for(int i=audioStartIdx;i<endIdx;i++) {
        // do a thing
        bufferPtr[c++] = audioBuffer[i];
    }
    
    if (wrapped) {
        //we have extra
        for(int i=0;i<endSnapshotIdx;i++) {
            // do more of a thing.
            bufferPtr[c++] = audioBuffer[i];
        }
    }
    
    //and we're done.
    audioStartIdx = audioEndIdx;
    
    if (c < AUDIO_BUFFER_MAX) {
        bufferPtr[c] = -1;
    }
}

// Callback for Timer 1
void sendAudio(void) {
    copyAudio(txBuffer);
    
    int i=0;
    uint16_t val = 0;
        
    if (audioClient.connected()) {
       write_socket(audioClient, txBuffer);
    }
    else {
        while( (val = txBuffer[i++]) < 65535 ) {
            Serial.print(val);
            Serial.print(',');
        }
        Serial.println("DONE");
    }
}


// an audio sample is 16bit, we need to convert it to bytes for sending over the network
void write_socket(TCPClient socket, uint16_t *buffer) {
    int i=0;
    uint16_t val = 0;
    
    int tcpIdx = 0;
    uint8_t tcpBuffer[1024];
    
    while( (val = buffer[i++]) < 65535 ) {
        if ((tcpIdx+1) >= 1024) {
            socket.write(tcpBuffer, tcpIdx);
            tcpIdx = 0;
        }
        
        tcpBuffer[tcpIdx] = val & 0xff;
        tcpBuffer[tcpIdx+1] = (val >> 8);
        tcpIdx += 2;
    }
    
    // any leftovers?
    if (tcpIdx > 0) {
        socket.write(tcpBuffer, tcpIdx);
    }
}
    

waveRecorder.js

// make sure you have Node.js Installed!
// Get the IP address of your photon, and put it here:

// CLI command to get your photon's IP address
//
// particle get MY_DEVICE_NAME ipAddress

// Put your IP here!
var settings = {
	ip: "YOUR_IP_ADDRESS_HERE",
	port: 3443
};

/**
 * Created by middleca on 7/18/15.
 */

//based on a sample from here
//	http://stackoverflow.com/questions/19548755/nodejs-write-binary-data-into-writablestream-with-buffer

var fs = require("fs");

var samplesLength = 1000;
var sampleRate = 8000;

var outStream = fs.createWriteStream("test.wav");

var writeHeader = function() {
	var b = new Buffer(1024);
	b.write('RIFF', 0);
	/* file length */
	b.writeUInt32LE(32 + samplesLength * 2, 4);
	//b.writeUint32LE(0, 4);

	b.write('WAVE', 8);
	/* format chunk identifier */
	b.write('fmt ', 12);

	/* format chunk length */
	b.writeUInt32LE(16, 16);

	/* sample format (raw) */
	b.writeUInt16LE(1, 20);

	/* channel count */
	b.writeUInt16LE(1, 22);

	/* sample rate */
	b.writeUInt32LE(sampleRate, 24);

	/* byte rate (sample rate * block align) */
	b.writeUInt32LE(sampleRate * 2, 28);

	/* block align (channel count * bytes per sample) */
	b.writeUInt16LE(2, 32);

	/* bits per sample */
	b.writeUInt16LE(16, 34);

	/* data chunk identifier */
	b.write('data', 36);

	/* data chunk length */
	//b.writeUInt32LE(40, samplesLength * 2);
	b.writeUInt32LE(0, 40);


	outStream.write(b.slice(0, 50));
};





writeHeader(outStream);





var net = require('net');
console.log("connecting...");
client = net.connect(settings.port, settings.ip, function () {
	client.setNoDelay(true);

    client.on("data", function (data) {
        try {
			console.log("GOT DATA");
			outStream.write(data);
			//outStream.flush();
			console.log("got chunk of " + data.toString('hex'));
		}
        catch (ex) {
            console.error("Er!" + ex);
        }
    });
});




setTimeout(function() {
	console.log('recorded for 10 seconds');
	client.end();
	outStream.end();
	process.exit(0);
}, 10 * 1000);

Hey! Great project - following the steps.

Added an auto-detection of ip Address: https://gist.github.com/kindanduseful/ab65eec42629e051e2d633e1bfe7defd