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Photon Audio Example
#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);
}
}
// 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);
@thiemehennis

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thiemehennis commented Sep 30, 2015

Possibly a stupid question, but where does the file get written to? I am trying to see if it works, but I cannot find any test.wav anywhere..

Also I was expecting a URL so the sound can be transmitted through the cloud in realtime. Would that be possible?

@kindanduseful

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kindanduseful commented Apr 15, 2016

Hey! Great project - following the steps.

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

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