DECLARE SUB SETPin (Pin AS INTEGER, state AS INTEGER)
DECLARE SUB GetPublicData (Pin AS INTEGER, Result AS LONG)
DECLARE SUB TRANSACTION ()
DECLARE SUB RESYNC ()

'Declare an array for storing/passing RX Data
DIM SHARED RXARRAY(8) AS INTEGER

'RXCount is used by the interrupt to keep track of
'The number of bytes received so far.  Reset to 0 at the
'Beginning of each transaction
DIM SHARED RXCount AS INTEGER
'RX Result.  0 = In progress, 1=Success, 2 = Timeout
DIM SHARED RXRESULT AS INTEGER

'Array to pass transmit data in
DIM SHARED TXARRAY(8) AS INTEGER

	CLS

' Open serial port and surpress all hardware handshaking, set interrupt
	OPEN "COM1:9600,N,8,1,BIN,CD0,CS0,DS0,OP0,RS" FOR RANDOM AS #1
	ON COM(1) GOSUB RXHANDLER
	RXCount = 0
	RXRESULT = 0
	COM(1) ON

	CALL RESYNC

DIM Result AS LONG
MainLoop:

CALL GetPublicData(2, Result)
IF (RXRESULT = 1) THEN
	PRINT "Result was "; Result

END IF


GOTO MainLoop


  END


RXHANDLER:
  DIM rxin AS STRING
  n = LOC(1)
  rxin = INPUT$(n, 1)
  FOR i = 1 TO LEN(rxin)
  IF (RXCount < 8) THEN
	RXCount = RXCount + 1
	RXARRAY(RXCount) = ASC(MID$(rxin, i, 1))
  END IF
  NEXT
  IF (RXCount = 8) THEN
	RXRESULT = 1
  END IF
RETURN

SUB GetPublicData (Pin AS INTEGER, Result AS LONG)
	TXARRAY(1) = ASC("A")

	'Convert Pin to ascii
	TXARRAY(2) = Pin \ 10 + ASC("0")
	TXARRAY(3) = (Pin MOD 10) + ASC("0")
	'D for decimal:
	TXARRAY(4) = ASC("D")
	'Last 4 unused:
	TXARRAY(5) = ASC("U")
	TXARRAY(6) = ASC("U")
	TXARRAY(7) = ASC("U")
	TXARRAY(8) = ASC("U")

	CALL TRANSACTION

	IF (RXRESULT = 1) THEN
	     Result = 0
	     Result = Result + RXARRAY(8) - ASC("0")
	     Result = Result + (RXARRAY(7) - ASC("0")) * 10
	     Result = Result + (RXARRAY(6) - ASC("0")) * 100
	     Result = Result + (RXARRAY(5) - ASC("0")) * 1000
	     DIM TEMP AS LONG
	     TEMP = RXARRAY(4) - ASC("0")
	     TEMP = TEMP * 10000
	     Result = Result + TEMP

	ELSE
	    'Error.  Return -1
	    Result = -1
	END IF

    
END SUB

SUB RESYNC
	TXARRAY(1) = 85
	TXARRAY(2) = 85
	TXARRAY(3) = 85
	TXARRAY(4) = 85
	TXARRAY(5) = 85
	TXARRAY(6) = 85
	TXARRAY(7) = 85
	TXARRAY(8) = 85
	CALL TRANSACTION
END SUB

SUB SETPin (Pin AS INTEGER, state AS INTEGER)
	TXARRAY(1) = ASC("P")

	'Convert Pin to ascii
	TXARRAY(2) = Pin \ 10 + ASC("0")
	TXARRAY(3) = (Pin MOD 10) + ASC("0")
	IF (state = 0) THEN
		TXARRAY(4) = ASC("0")
	ELSEIF (state = 1) THEN
		TXARRAY(4) = ASC("1")
	ELSEIF (state = 2) THEN
		TXARRAY(4) = ASC("I")
	ELSE
		TXARRAY(4) = ASC("U")
	END IF
	TXARRAY(5) = ASC("U")
	TXARRAY(6) = ASC("U")
	TXARRAY(7) = ASC("U")
	TXARRAY(8) = ASC("U")

	CALL TRANSACTION
END SUB

SUB TRANSACTION
'This Subroutine is used to send 8 bytes to The Wombat, and wait for 8
'bytes back.  It assumes that this can occur within 1 second (shouldn't
' be a problem).  It creates an output string from TXARRAY, and dumps
' it to the serial port.  This is necessary because QBasic doesn't have
' a byte type; It's integer type is 16 bits, so to get 8 bytes, you need
' a string of 8 characters.
' After the string is sent to the port ( I assume this is just queuing it
' in the FIFO, but i don't know), the Wombat uses the timer function to
' get the number of seconds since Midnight.  It waits for one of two things
' to happen:
' RXResult gets set to 1 by the Receive interrupt
' OR
' Timer changes values twice.  This means that between 1 and 2
' Seconds have passed since we first transmitted, So we time out
' The message.
' We could have used the QBasic ON TIMER functionality to do this,
' but since this timeout task is so simple, it seems smart not to
' waste ON TIMER on such a simple task.

   DIM TryNumber AS INTEGER
   TryNumber = 1
   output$ = "UUUUUUUU"
   FOR i = 1 TO 8
	MID$(output$, i, 1) = CHR$(TXARRAY(i))
   NEXT i
TRYAGAIN:
   RXRESULT = 0
   RXCount = 0
   RXARRAY(1) = ASC("X")
   RXARRAY(2) = ASC("X")
   RXARRAY(3) = ASC("X")
   RXARRAY(4) = ASC("X")
   RXARRAY(5) = ASC("X")
   RXARRAY(6) = ASC("X")
   RXARRAY(7) = ASC("X")
   RXARRAY(8) = ASC("X")
   PRINT #1, output$;
   DIM TimechangeCounter AS INTEGER
   TimechangeCounter = 0
   StartTime = TIMER
   WHILE (RXRESULT = 0)
	NewTime = TIMER
	IF (StartTime <> NewTime) THEN
	   TimechangeCounter = TimechangeCounter + 1
	   StartTime = NewTime
	   IF (TimechangeCounter > 1) THEN
		RXRESULT = 2
'Comment out the following code if desired.
		PRINT "Timeout!"
	   END IF
	END IF
   WEND
   IF (RXRESULT = 1 AND RXARRAY(1) = ASC("E")) THEN
	' ERROR was received. 
	RXRESULT = 3
   END IF

  
   IF ((RXRESULT <> 1)) THEN
	'ERROR State.  Send RESYNC, and Try again
	IF (TryNumber = 1) THEN
	    PRINT #1, "UUUUUUUUUUUUUU"
	    TryNumber = 2
	    GOTO TRYAGAIN
	END IF
   END IF


'Print out the TX and RX packets.  Comment out if desired.
   IF (RXRESULT = 1) THEN
	PRINT USING "### "; TXARRAY(1);
	PRINT USING "### "; TXARRAY(2);
	PRINT USING "### "; TXARRAY(3);
	PRINT USING "### "; TXARRAY(4);
	PRINT USING "### "; TXARRAY(5);
	PRINT USING "### "; TXARRAY(6);
	PRINT USING "### "; TXARRAY(7);
	PRINT USING "###       "; TXARRAY(8);
	PRINT USING "### "; RXARRAY(1);
	PRINT USING "### "; RXARRAY(2);
	PRINT USING "### "; RXARRAY(3);
	PRINT USING "### "; RXARRAY(4);
	PRINT USING "### "; RXARRAY(5);
	PRINT USING "### "; RXARRAY(6);
	PRINT USING "### "; RXARRAY(7);
	PRINT USING "### "; RXARRAY(8)
   END IF



END SUB