old_contents: var SPI = require('spi');
  var median = require('median')
  var average = [];
  var lastAverage;
  var averageCount =0;
  var signalMax = 0;
  var signalMin = 4096;
  var peakToPeak;
  
  var spi = new SPI.Spi('/dev/spidev0.1', {
      'mode': SPI.MODE['MODE_0'],  // always set mode as the first option
      'chipSelect': SPI.CS['none'] // 'none', 'high' - defaults to low
    }, function(s){
      s.maxSpeed(6000000);
      s.open();
    });
  
  var txbuf = new Buffer([ 0x23, 0x48, 0xAF, 0x19, 0x19, 0x19 ]);
  var rxbuf = new Buffer([ 0x00, 0x00, 0x00]);
  
  setInterval(function(){
    spi.read(rxbuf, function(device, buf) {
      //console.log(buf.readUInt16BE(0));
      var sample = buf.readUInt16BE(0);
      if (sample > signalMax)
           {
              signalMax = sample;  // save just the max levels
           }
           else if (sample < signalMin)
           {
              signalMin = sample;  // save just the min levels
           }
    });
  },1);
  
  setInterval(function(){
   peakToPeak = 0;
   peakToPeak = signalMax - signalMin;  // max - min = peak-peak amplitude
   if(average.length == 20){
     var first = average.pop();
   }
   average.push(peakToPeak);
   var outString = "";
   for(var i = 0; i<peakToPeak/10;i++){
     outString += " ";
   }
   outString += "*";
   var value = median(average);
   console.log("median value is " + value + " First was: "+ first + " Array: " + average.toString());
   //console.log(outString);
   signalMax = 0;
   signalMin = 4096;
  },50);
  
new_contents: var SPI = require('spi');
  var median = require('median')
  var average = [];
  var lastAverage;
  var averageCount =0;
  var signalMax = 0;
  var signalMin = 4096;
  var peakToPeak;
  
  var spi = new SPI.Spi('/dev/spidev0.1', {
      'mode': SPI.MODE['MODE_0'],  // always set mode as the first option
      'chipSelect': SPI.CS['none'] // 'none', 'high' - defaults to low
    }, function(s){
      s.maxSpeed(6000000);
      s.open();
    });
  
  var txbuf = new Buffer([ 0x23, 0x48, 0xAF, 0x19, 0x19, 0x19 ]);
  var rxbuf = new Buffer([ 0x00, 0x00, 0x00]);
  
  setInterval(function(){
    spi.read(rxbuf, function(device, buf) {
      //console.log(buf.readUInt16BE(0));
      var sample = buf.readUInt16BE(0);
      if (sample > signalMax)
           {
              signalMax = sample;  // save just the max levels
           }
           else if (sample < signalMin)
           {
              signalMin = sample;  // save just the min levels
           }
    });
  },1);
  
  setInterval(function(){
   peakToPeak = 0;
   peakToPeak = signalMax - signalMin;  // max - min = peak-peak amplitude
   if(average.length == 20){
     var first = average.pop();
   }
   average.unshift(peakToPeak);
   var outString = "";
   for(var i = 0; i<peakToPeak/10;i++){
     outString += " ";
   }
   outString += "*";
   var value = median(average);
   console.log("median value is " + value + " First was: "+ first + " Array: " + average.toString());
   //console.log(outString);
   signalMax = 0;
   signalMin = 4096;
  },50);
  
subject: add median output