Add firware example for playing sound from sd card

firmware/firmware.ino

@@ -0,0 +1,65 @@
+#include <SD.h>                      // need to include the SD library
+//#define SD_ChipSelectPin 53  //example uses hardware SS pin 53 on Mega2560
+#define SD_ChipSelectPin 5  //using digital pin 4 on arduino nano 328, can use other pins
+#include <TMRpcm.h>           //  also need to include this library...
+#include <SPI.h>
+
+TMRpcm tmrpcm;   // create an object for use in this sketch
+
+unsigned long time = 0;
+
+void setup(){
+
+  tmrpcm.speakerPin = 9; //5,6,11 or 46 on Mega, 9 on Uno, Nano, etc
+  //Complimentary Output or Dual Speakers:
+  //pinMode(10,OUTPUT); Pin pairs: 9,10 Mega: 5-2,6-7,11-12,46-45 
+  
+  Serial.begin(9600);
+  //pinMode(13,OUTPUT); //LED Connected to analog pin 0
+  if (!SD.begin(SD_ChipSelectPin)) {  // see if the card is present and can be initialized:
+    Serial.println("SD fail");  
+    return;   // don't do anything more if not
+
+  }
+  else{   
+    Serial.println("SD ok");   
+  }
+  tmrpcm.volume(2);
+  tmrpcm.play("coffee.wav"); //the sound file "music" will play each time the arduino powers up, or is reset
+}
+
+
+
+void loop(){
+  //blink the LED manually to demonstrate music playback is independant of main loop
+  if(tmrpcm.isPlaying() && millis() - time > 50 ) {      
+      //digitalWrite(13,!digitalRead(13));
+     // time = millis();    
+  }else
+  if(millis() - time > 500){     
+    //digitalWrite(13,!digitalRead(13)); 
+    //time = millis(); 
+  }
+
+
+  if(Serial.available()){    
+    switch(Serial.read()){
+    case 'c': tmrpcm.play("coffee.wav"); break;
+    case 'p': tmrpcm.pause(); break;
+    case '?': if(tmrpcm.isPlaying()){ Serial.println("A wav file is being played");} else{Serial.println("No wav file is being played");} break;
+    case 'S': tmrpcm.stopPlayback(); break;
+    case '0': tmrpcm.volume(0); break;
+    case '1': tmrpcm.volume(1); break;
+    case '2': tmrpcm.volume(2); break;
+    case '3': tmrpcm.volume(3); break;
+    case '4': tmrpcm.volume(4); break;
+    case '5': tmrpcm.volume(5); break;
+    case '6': tmrpcm.volume(6); break;
+    case '7': tmrpcm.volume(7); break;
+    case '=': tmrpcm.quality(0); break;
+    case '-': tmrpcm.quality(1); break;
+    default: break;
+    }
+  }
+
+}