//
// Copyright 2014, Aaron Ardiri
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// simple arduino sketch using six LED's and the piezo element 
//
// - design is to implement an LED binary counter (0..59 seconds)

#define ledPINBase    2
#define ledPINCount   6  // pins 2,3,4,5,6 and 7
#define piezoPIN      8

// we want to count seconds
#define delayPeriod   1000
#define sec_in_min    60

// we want to play tones an octive up and down from middle C
#define toneBase      440
#define toneDuration  25

// some global variables
int counter = 0;

// configuration of the arduino 
void setup()
{
  // configure the LED pins - turn them all off
  for (int i=ledPINBase; i<(ledPINBase+ledPINCount); i++)
  {
    pinMode(i, OUTPUT);
    digitalWrite(i, LOW);
  }
}

// called periodically by the arduino core - this is where we do stuff
void loop()
{
  int b, led;
    
  counter++;
  if (counter == sec_in_min) counter = 0;
  
  // turn on/off bits as appropriate for the binary representation
  b   = 0x20;  // 00100000b
  led = ledPINBase;
  while (b != 0)
  {
    // depending if the bit is set; turn on/off an LED
    if (counter & b) digitalWrite(led, HIGH);
    else             digitalWrite(led, LOW);
    
    // move to the next bit, LED
    b = b >> 1; 
    led++;
  }
        
  // play a ticking sound, or when a minute is reached - longer tone
  if (counter == 0) tone(piezoPIN, toneBase * 5, toneDuration * 20);
  else              tone(piezoPIN, toneBase, toneDuration);
      
  // wait a specific period of time before the next iteration
  delay(delayPeriod);
}