Use rectifier DF02 + sn754410 H-bridge + XOR gates

	;Pins
DEVICE	 SX28, OSCHCS3, TURBO, STACKX, OPTIONX
IRC_CAL  IRC_FAST
FREQ	 50000000
	
		'Pins
StepperCoil1	var	RB.0	OUTPUT	
StepperCoil2	var 	RB.1	OUTPUT
StepperCoil3	var 	RB.2	OUTPUT
StepperCoil4	var	RB.3	OUTPUT 
FIDLEPulse	var 	RB.5	INPUT
SleepSense	Var	RB.6	INPUT	'Always high, unless powered down.


		'Variables
DutyCycle	Var	word
StepPos		var	byte
	
PULSEIN Pin 5 = Var(Y) 				;range from 1 to 50
IdealStepPosition = Var(X) 			;range from 1 to 250

		'Main Protocol
MAIN:
IF 	SleepSense=0 
	THEN 	Pause	500
 		GOTO	Main


Poll Pin6
	If 
		Pin6 = True
			Call ClearCoils
	Else 
		continue with "Main"
Poll Y
	(5)Y=X
Skip if not zero (snz)	Bank 5
Write (X)		Bank 5
Call ForwardStep (X) times
Call Main					;Return to main
If
	(Bank 5)-(X)<10
	or
	(X)-(Bank 5)>10
		Call Main 
	else
		if				;nested if/then statement
		(Bank 5)-(X) = (x') = True 	;if this is a positive number 
			Clear 		Bank 5
			Write (X+X')	Bank 5
			Call ForwardStep (X') times
		else	
		(X)-(Bank 5) = (X')		;this will be positive
			Clean 		Bank 5
			Write (X-X')	Bank 5
			Call ReverseStep (X') times
Call Main


	;Subroutines

ForwardStep

skip if not zero (snz)   Bank 1
Output pin 1 (1)
    Write (1)            Bank 1
	Call HoldCoils

skip if not zero (snz)   Bank 2
Output pin 2 (1)
    Write (1)            Bank 2
	Call HoldCoils

skip if not zero (snz)   Bank 3
Output pin 3 (1)
    Write (1)            Bank 3
	Call HoldCoils

skip if not zero (snz)   Bank 4
Output pin 4 (1)
    Write (1)            Bank 4
	Call HoldCoils

Clear
	Bank 1
	Bank 2
	Bank 3
	Bank 4

Ret




ReverseStep

skip if not zero (snz)   Bank 4
Output pin 4 (1)
    Write (1)            Bank 4
	Call HoldCoils

skip if not zero (snz)   Bank 3
Output pin 3 (1)
    Write (1)            Bank 3
	Call HoldCoils

skip if not zero (snz)   Bank 2
Output pin 2 (1)
    Write (1)            Bank 2
	Call HoldCoils

skip if not zero (snz)   Bank 1
Output pin 1 (1)
    Write (1)            Bank 1
	Call HoldCoils

Clear
	Bank 1
	Bank 2
	Bank 3
	Bank 4

Ret



HoldCoils 			;I want this routine to continue functioning,
HIGH 1 				;until ForwardStep/ReverseStep is called on
HIGH 2 				;again, or if ClearCoils is called on.
HIGH 3 				;I don't know how to do that, though.
HIGH 4 
ret



ClearCoils			;Shutdown routine
LOW 1
LOW 2 
LOW 3 
LOW 4 
Clear Bank5
ret 