' Name        : HSERX3.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : PIC16F627A or similar 18-pin type compatible with LAB-X3 board
' Hardware    : LAB-X3 Experimenter Board
' Oscillator  : 4MHz external crystal
' Keywords    : HSERIN, HSEROUT
' Description : PICBASIC PRO program to send and receive from the hardware
' serial port. LEDs count characters and flash error if none received for
' 10 seconds.
'

char Var Byte   ' Storage for serial character
cnt  Var Byte   ' Storage for character counter

   TRISB = %11001111 ' Set PORTB.4,5 to outputs
   PORTB = 0         ' Turn off LEDs
   cnt = 0           ' Zero character counter

mainloop:
   Hserin 10000, allon, [char]  ' Get a char from serial port
   Hserout [char]               ' Send char out serial port

   cnt = cnt + 1     ' Increment character count
   PORTB = cnt << 4  ' Send count to LED
   Goto mainloop     ' Do it all over again

allon:
   PORTB = %00110000 ' Error - no character received
   Pause 500         ' Blink all LEDs
   PORTB = 0
   Pause 500
   Goto allon

   End