/*

Andrew Anselmo
Clipboard Engineering

Test code for Arduino+XBee base unit.

Four bits are toggled on and off every 250 ms (20 Hz); (bits 2-5); they are hooked up to the Arduino XBee inputs 0-4.

Note that a resistor divider must be used; the Arduino UNO uses 0-5 V, and the XBee uses 0-3.3 V.

*/

int led = 13;
int i;

int output_pins[4]={2,3,4,5};

void setup() {    
            
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
  
  
  // simple
  /*
  for(i=0;i<=3;i++)
  {
  pinMode(output_pins[i],OUTPUT); 
  }
  */
  
  // output bits
  DDRD = DDRD | B11111100;

}

// the loop routine runs over and over again forever:
void loop() {
  
  
  // simple; not simultaneous enough!
  // This 50 ms on/50 ms off; this is 10 Hz
  /*
  for(i=0;i<=3;i++)
  {
    digitalWrite(output_pins[i],HIGH); 
  }
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  
  delay(50);               // wait for 50 ms
  
  for(i=0;i<=3;i++)
  {
    digitalWrite(output_pins[i],LOW); 
  }
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(50);               // wait for 50 ms
  */
  
  // simultaneous is nicer; all bits go on and off at the same time.
  // on-off cycle is 500 ms, 20 Hz
  
  //      B76543210
  PORTD = B00111100;
  delay(250);

  //      B76543210
  PORTD = B00000000;
  delay(250);
  
  
}