#ifndef __SERIAL_H__
  #define __SERIAL_H__
  
  #include <avr/io.h>		// for the input/output register
  #include <util/delay.h>
  
  #define CPU_FREQ        16000000L       // Assume a CPU frequency of 16Mhz
  
  void init_serial(unsigned long int speed);
  void send_serial(uint8_t c);
  uint8_t get_serial(void);
  void send_ack(void);
  #endif