// //////////////////////////////////////////////////
// ESP (CS 33301-001)
// Code 1.1: Input - Polling --> Built-in LED ON OFF
// Kent State University
// Dept. of Computer Science
// Jungyoon Kim, Ph.D.
// //////////////////////////////////////////////////

#define BIT5_MASK 0x20    // Bit map - 0010 0000 --> Pin 5 

#define PORTB_MASK 0x25   // Address of Portb
#define DDRB_MASK 0x24    // Address of DDRB

unsigned char *portDDRB;  // Pointer for DDRB
unsigned char *portB;     // Pointer for PortB

// Determine MyDelay function
void MyDelay(unsigned long mSec);

// The setup function runs once when you press reset or power the board
void setup() {
  // Port B
  portDDRB = (unsigned char *) DDRB_MASK;
  *portDDRB |= BIT5_MASK;     // Configure bit 5 as an output
  portB = (unsigned char *) PORTB_MASK;
  *portB &= ~BIT5_MASK;
 }

// the loop function
void loop() {
    *portB |= BIT5_MASK;    // LED On:    xx1x xxxx
    MyDelay(1000);          // about 1 second
    *portB &= ~BIT5_MASK;   // LED OFF:   xx0x xxxx
    MyDelay(1000);          // about 1 second
}

// Define MyDelay function 
void MyDelay(unsigned long mSec)
{
  volatile unsigned long i;
  unsigned long endT = 500 * mSec;
  for (i = 0; i < endT; i++);
}