Noble + Gavia // Practice Code and Replacement Parts

Since our parts haven't arrived in the mail yet, we made do with what the Sparkfun Inventor's Kit had.  We used the kit's piezo instead of a larger one, a potentiometer instead of a vibration sensor, a button instead of an infrared remote switch, and base LEDs instead of brighter ones.  I recently bought a larger servo from radioshack for the part where it shoots silly string, but this part of the project was done before then.

I coded the Arduino to arm itself when the button is pressed.  A LED comes on to show that it's armed and if the potentiometer's analog reading reaches a certain value, red LEDs flash on and the piezo makes a buzzing noise.  This code has the basic logic of our system.  The system can be armed or disarmed, and the sensor triggers a reaction once a certain value is detected.

Here's our code:


#define LED_ALARM 13   //Red LEDS on output pin 13
#define LED_ON 12   //Green LED on ouotput pin 12
#define BUTTON 2   //Button switch on input pin 2
#define SENSORPIN 0   //Potentiometer on analog input pin A0
#define BUZZER 11   //Piezo buzzer on output pin 11

int val = 0;   //It's value changes based on whether the button is pressed or not
int old_val = 0;   //Stores the old value of the button so it properly turn on or off
int state = 0;   //State of the button, is it on or off?
int sensorValue;   //Value of the potentiometer

void setup() {                
  pinMode(LED_ALARM, OUTPUT);
  pinMode(LED_ON, OUTPUT);
  pinMode(BUTTON, INPUT);
  pinMode(BUZZER, OUTPUT);
}

void loop() {
   val = digitalRead(BUTTON);   //Sets the value to LOW or HIGH based on the button being pressed or not

   if ((val == HIGH) && (old_val == LOW)){   //Changes the state of the button to on or off
     state = 1 - state;
     delay(10);
   }
   
   old_val = val;   //So we know that we're going from one button state to another when it's pressed
   
   if (state == 1) {   //If the button is pressed the green light comes on and the potentiometer starts to read
     digitalWrite(LED_ON, HIGH);
     sensorValue = analogRead(SENSORPIN);
   } else {
     digitalWrite(LED_ON, LOW);    //If the button isnt pressed then the light is off
   }
   if (sensorValue > 500) {   //If the potentiometer is a certain value, the alarm sounds and the red LEDs flash
      digitalWrite(LED_ALARM, HIGH);
      delay(250);
      digitalWrite(LED_ALARM, LOW);
      delay(250);
      
      buzz(BUZZER, 2500, 500);   //buzz the buzzer on pin 11 at 2500Hz for 500 milliseconds
      delay(1000);
    }
}

void buzz(int targetPin, long frequency, long length) {
  long delayValue = 1000000/frequency/2;     //calculate the delay value between transitions
  //// 1 second's worth of microseconds, divided by the frequency, then split in half since
  //// there are two phases to each cycle
  long numCycles = frequency * length/ 1000;    //calculate the number of cycles for proper timing
  //// multiply frequency, which is really cycles per second, by the number of seconds to 
  //// get the total number of cycles to produce
 for (long i=0; i < numCycles; i++){    //for the calculated length of time...
    digitalWrite(targetPin,HIGH);    //write the buzzer pin high to push out the diaphragm
    delayMicroseconds(delayValue);    //wait for the calculated delay value
    digitalWrite(targetPin,LOW);    //write the buzzer pin low to pull back the diaphragm
    delayMicroseconds(delayValue);    //wait again for the calculated delay value
  }
}