/*                            PIC16F84
 *                          .-----------.
 *                         -|RA2     RA1|- TRANSMIT (MAX232 PIN 11)
 *                         -|RA3     RA0|- 
 *                         -|RA4    OSC1|- XT CLOCK pin1, 27pF to GND
 *             PUSH BUTTON -|MCLR   OSC2|- XT CLOCK pin2, 27pF to GND
 *                     GND -|Vss     Vdd|- +5v
 * RECEIVE (MAX232 PIN 12) -|RB0     RB7|- 
 *                         -|RB1     RB6|- 
 *                         -|RB2     RB5|- 
 *                         -|RB3     RB4|- 
 *                          '-----------'       
 *
 *  PUSH BUTTON = PIN - BUTTON - GND
 *                PIN - 10k - +5v  
 */

/*                                 MAX232
 *                      .-----------------.
 *               cap1+ -|1 C1+      Vcc 16|- +5v
 *        GND -- cap3+ -|2 Vs+      GND 15|- GND
 *               cap1- -|3 C1-    T1out 14|- SERIAL COARD white
 *               cap2+ -|4 C2+     R1in 13|- SERIAL COARD orange
 *               cap2- -|5 C2-    R1out 12|- PIC RB0
 *        GND -- cap4- -|6 Vs-     T1in 11|- PIC RA1
 *                     -|7 T2out   T2in 10|- 
 *                     -|8 R2in    R2out 9|- 
 *                      '-----------------'    
 *
 *  Note the need for four 10uF capacitors.
 *  Capacitors 1 and 2 go from pin to pin,
 *  and capacitors 3 and 4 go from pin to GND (watch the polarities).
 */

/*  looking head on at the female connector of a serial mouse coard:
 *  i.e. the end that plugs into your pc
 *
 *  5 4 3 2 1      =      blue    null    orange      white    null
 *   9 8 7 6       =          null    null      yellow     null
 *
 *  the following are loose wires on the other end of the coard.
 *  i.e. where it would have been soldered to the mouse circuit board.
 *
 *  5 = blue   = gnd = GND
 *  3 = orange = td  = MAX232 PIN13 R1IN
 *  2 = white  = rd  = MAX232 PIN14 T1OUT
 *  7 = yellow = rts = unused
 */

#include <pic.h>
#include "rs232.c"

__CONFIG(WDTDIS & XT & UNPROTECT);

main(void) 
{
  TRISA = 0b00000000;
  TRISB = 0b00000001;
  PORTA = 0;
  PORTB = 0;

  rs232_initialize();

  rs232_send_string("Hello: ");
  for (;;) 
  {
    rs232_echo_char();
  }
}