using namespace std;

#include <stdint.h>
#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

static long pdelay;

// busy loop delay
static void delay()
{
  for (long i=0; i<pdelay; i++) ;
}

static void longdelay()
{
  for (int i=0; i<10; i++)
    delay();
}

void writebyte(int fd, uint8_t val)
{
  char buflow[1], bufhigh[1];
  buflow[0] = '0';
  bufhigh[0] = '1';

  write(fd, buflow, 1);     // start bit
  delay();

  uint8_t tmp = val;
  for (int i=0; i<8; i++)
  {
    if (tmp & 0x01)
    {
      write(fd, bufhigh, 1);
    }
    else
    {
      write(fd, buflow, 1);
    }
    delay();
    tmp = tmp >> 1;  // right shift by one bit
  }

  write(fd, bufhigh, 1);    // stop bit
  delay();
}

int main(int argc, char *argv[])
{
  // read in pulse delay
  cin >> pdelay;
  //cout << "pdelay = " << pdelay << endl;

  // read in two bytes
  uint8_t byte1 = 0x00, byte2 = 0x00;
  int tmp;
  cin >> tmp;
  for (int i=0; i<tmp; i++, byte1++);
  cin >> tmp;
  for (int i=0; i<tmp; i++, byte2++);

  // calculate checksum
  uint8_t checksum = byte1 + byte2;
  if (checksum == 0xff)
  {
    checksum = 0x00;
  }

  // read in number of times to send the frame
  int reps;
  cin >> reps;

  // gpio0/2 pin are dead on geode2 due to overvoltage accident
  // the pins are ok on geode1
  int fd = open("/dev/gpio0", O_WRONLY);
  if (fd == -1)
  {
    cerr << "open /dev/gpio0 failed" << endl;
    exit(1);
  }
  else
  {
    //cout << "open /dev/gpio0 ok" << endl;
  }

  // turn pin output on
  char buf[1];
  buf[0] = 'O';
  ssize_t nwri = write(fd, buf, 1);
  if (nwri != 1)
  {
    cerr << "failed to turn gpio0 pin on" << endl;
    exit(1);
  }
  else
  {
    //cout << "turned gpio0 pin on" << endl;
  }

  // set pin output high
  char bufhigh[1];
  bufhigh[0] = '1';
  if (write(fd, bufhigh, 1) != 1)
  {
    cerr << "failed to set pin high" << endl;
    exit(1);
  }
  else
  {
    //cerr << "set pin high, sleeping for one second" << endl;
    //sleep(1);
  }

  // loop forever
  while (reps--)
  {
    writebyte(fd, 0xff);
    writebyte(fd, byte1);
    writebyte(fd, byte2);
    writebyte(fd, checksum);
  }

  return 0;
}