Sainsmart 8 Channel Relay

I recently purchased a Sainsmart 8 channel relay for use with some holiday lighting with my Arduino, I had some sketches already typed up for use with another project however I soon discovered that the relay board does not simply turn off with the normal LOW command with the digital output pins.I basically spent half a day writing up a new sketch and trying it until I got it to perform the way that I wanted it to. I have an ITEAD Mp3 shield I am using with it, so I cant guarantee this sketch will work for anyone else, But it’s a starting point since I found hardly any information on this relay board.This page is the best information I found but it only loops the relays so I had to us his example to formulate the code to do as I wished.If you look at your serial output and adjust the sense limit and smoothing you can get it to react to some some degree to the music.

 

// Sainsmart 8 channel relay v1.0
// 



  #define NUMREADINGS 70 // raise this number to increase data smoothing

  int senseLimit = 400; // raise this number to decrease sensitivity (up to 1023 max)
  int probePin = 3; // analog 3
  int val = 0; // This is the reading from the probePin

  #define RELAY_ON 1
  #define RELAY_OFF 0

  #define Relay_1  4  // Arduino Digital I/O pin number
  #define Relay_2  5
  #define Relay_3  6
  #define Relay_4  7
  #define Relay_5  8  
  #define Relay_6  9
  #define Relay_7  10
  #define Relay_8  11


  // variables for smoothing

  int readings[NUMREADINGS];               // the readings from the current analog input
  int index = 0;                           // the index of the current reading
  int total = 8;                           // the running total (Realys)
  int average =0;                          // final average of the probe reading


  void setup() {

  
  pinMode(Relay_8, OUTPUT);   // specify Relay Outputs
  pinMode(Relay_7, OUTPUT);  
  pinMode(Relay_6, OUTPUT);  
  pinMode(Relay_5, OUTPUT);    
  pinMode(Relay_4, OUTPUT);   
  pinMode(Relay_3, OUTPUT);  
  pinMode(Relay_2, OUTPUT);  
  pinMode(Relay_1, OUTPUT);

  Serial.begin(9600);  // initiate serial connection for debugging/etc

  for (int i = 0; i < NUMREADINGS; i++)
    readings[i] = 0;                      // initialize all the readings to 0
  }

  void loop() {

  val = analogRead(probePin);  // take a reading from the probe

  if(val >= 1){                            // if the reading isn't zero, proceed

    val = constrain(val, 1, senseLimit);  // turn any reading higher than the senseLimit value into the senseLimit       value
    val = map(val, 1, senseLimit, 1, 1023); // remap the constrained value within a 1 to 1023 range

    total -= readings[index];               // subtract the last reading
    readings[index] = val;                  // read from the sensor
    total += readings[index];               // add the reading to the total
    index = (index + 1);                    // advance to the next index

    if (index >= NUMREADINGS)               // if we're at the end of the array...
      index = 0;                            // ...wrap around to the beginning

    average = total / NUMREADINGS;          // calculate the average


    if (average > 250){                     // if the average is over 250 ...
      digitalWrite(Relay_1, RELAY_ON);      // Turn on the first Relay*
    }
    else{                                   // and if it's not ...
      digitalWrite(Relay_1, RELAY_OFF);     // turn that Relay off
    }

    if (average > 300){               // and so on ...
      digitalWrite(Relay_2, RELAY_ON);
    }
    else{
      digitalWrite(Relay_2, RELAY_OFF);
    }

    if (average > 350){
      digitalWrite(Relay_3, RELAY_ON);
    }
    else{
      digitalWrite(Relay_3, RELAY_OFF);
    }

    if (average > 375){
      digitalWrite(Relay_4, RELAY_ON);
    }
    else{
      digitalWrite(Relay_4, RELAY_OFF);
    }

    if (average > 400){
      digitalWrite(Relay_5, RELAY_ON);
    }
    else{
      digitalWrite(Relay_5, RELAY_OFF);
    }

    if (average > 450){
      digitalWrite(Relay_6, RELAY_ON);
    }
    else{
      digitalWrite(Relay_6, RELAY_OFF);
    }

    if (average > 550){
      digitalWrite(Relay_7, RELAY_ON);
    }
    else{
      digitalWrite(Relay_7, RELAY_OFF);
    }

    if (average > 600){
      digitalWrite(Relay_8, RELAY_ON);
    }
    else{
      digitalWrite(Relay_8, RELAY_OFF);
    }


    Serial.println(val); // use this output to aid in calibrating
  }
}