gistfile1.c

/* 
I used the Serial Call and Response example sketch and modified it
This program similarly sends an ASCII A (byte of value 65) on 
startup and repeats that until it gets some data in.
 
Then it waits for a byte in the serial port, and 
sends sensor values whenever it gets a byte in.
 
 The circuit:
 * 5 piezos hooked up to Analog Pins 0-4
 [Use roughly 1M resistors for each]
 
 */
 
const int firstSensor = 0; 
//declares that each sensor is connected to Analog Pins 0-4
const int secondSensor = 1;
const int thirdSensor = 2;
const int fourthSensor = 3;
const int fifthSensor = 4;
 
int sensorReading1 = 0;   // first analog sensor reading
int sensorReading2 = 0;   // second analog sensor reading
int sensorReading3 = 0;   // and so on...
int sensorReading4 = 0;
int sensorReading5 = 0;
int inByte = 0;           // incoming serial byte
const int threshold = 100; 
//constant threshold of the knock sensors
 
void setup()
{
  // start serial port at 9600 bps:
  Serial.begin(9600);
}
 
void loop()
{
  // get incoming byte:
  inByte = Serial.read();
 
  sensorReading1 = analogRead(firstSensor); //read sensor
  if (sensorReading1 >= threshold) { 
  //if reading is greater than threshold
    Serial.println("k");             //print designated letter”
  }  
    
sensorReading2 = analogRead(secondSensor);
  if (sensorReading2 >= threshold) {
    Serial.println("b");
  }
 
  sensorReading3 = analogRead(thirdSensor); 
  if (sensorReading3 >= threshold) {
    Serial.println("s");
  }
 
  sensorReading4 = analogRead(fourthSensor); 
  if (sensorReading4 >= threshold) {
    Serial.println("c");
  }
 
  sensorReading5 = analogRead(fifthSensor); 
  if (sensorReading5 >= threshold) {
    Serial.println("h");
  }
}

Fix for https://plus.google.com/105372758468862415237/posts/6dUk78F6LUB