;****************************************************
;Nano Driver Stepper Motor Demo Code
;Authors: Dale Kubin & Nathan Scherdin
;Code demos how to control a stepper motor with 
;direction change based on the state of a pin.
;****************************************************

Speed	Var Word
Pot		Var Word

ENABLE1 CON P12
ENABLE2 CON P11

OUTA = 0
DIRA = 0 ; Sets Pin P0-P3 to outputs and low

High Enable1 ;Turn L293 On
High Enable2

Pot = 0 ;Clear the variable POT
Speed = 3 ;Set Stepper Motor Speed

Main
	If IN8 = 1 Then ;If P8 high goto ForwardMtr, if P8 low ReverseMtr
		Gosub ForwardMtr
	Else
		Gosub ReverseMtr
	Endif
	Goto Main

;In ForwardMtr and ReverseMtr loops we set all 4 control pins at the same time. 
;This makes the stepper motor run smoother. Using the OUTA command which addresses 
;the first Nib (P3,P2,P1,P0). 
		
ForwardMtr	
	OUTA = %0101 ; OUTA address P3,P2,P1,P0 as nibble.
	Pause Speed
	OUTA = %0110
	Pause Speed
	OUTA = %1010
	Pause Speed
	OUTA = %1001
	Pause Speed

	Return
	
ReverseMtr
	OUTA = %1010
	Pause Speed
	OUTA = %0110
	Pause Speed
	OUTA = %0101
	Pause Speed
	OUTA = %1001
	Pause Speed
	
	Return