'{$STAMP BS2}
' ==============================================================================
' File...... Ex26 - Stepper.BS2
' Purpose... Stepper Motor Control 
' E-mail.... stamptech@parallaxinc.com
' Started...
' Updated... 01 MAY 2002
' {$STAMP BS2}
' ==============================================================================
' ------------------------------------------------------------------------------
' Program Description
' ------------------------------------------------------------------------------
' This program demonstrates unipolar stepper motor control. The pot allows the
' program to control speed and direction of the motor.
' ------------------------------------------------------------------------------
' Revision History
' his version revised by Perry Hoberman 11/03 for CTIN534 class to
' use only one side (instead of both) of a 10K potentiometer for control
'
'-------------------------------------------------------------------------------
' Revision History
'	Revised March - Feb 2003 Bob Baer (rbaer@physics.siu.edu)
'	for dual stepper motor logic control.  
'	Motor turns left or right in single steps based on pulse width of
'	logic signal to p0 - motor 1 or p1 - motor 2.
'
' 5.17.2004 modify to use one input pulse to control the two motors
'
'
' ------------------------------------------------------------------------------
' ------------------------------------------------------------------------------
' I/O Definitions
' ------------------------------------------------------------------------------
PulseA CON 0 ' A motor input
'PulseB CON 1 ' B motor input
' PotCW CON 0 'clockwise pot input
CoilsA VAR OutB ' output  to motor A (pins 4, 5, 6, 7)
CoilsB VAR OutC ' output to motor B (pins 8, 9, 10, 11)
' ------------------------------------------------------------------------------
' Variables
' ------------------------------------------------------------------------------
speed VAR Word ' delay between steps
x VAR Byte ' loop counter
sAddrA VAR Byte ' EE address of step data for motor A
sAddrB VAR Byte ' EE address of step data for motor B
rcA VAR Word ' remote control reading motor A
rcB VAR Word ' remote control reading motor B
' diff VAR Word ' difference between readings
'
' motor A stepping at 1/2 steps, motor B stepping at full steps.
'

' ------------------------------------------------------------------------------
' EEPROM Data  Steps for motor A and B
' ------------------------------------------------------------------------------
' ABAB
' -----
Step1A DATA %1100 
Step2A DATA %0110
Step3A DATA %0011
Step4A DATA %1001  
Step1B DATA %1100  
Step2B DATA %0110
Step3B DATA %0011
Step4B DATA %1001 


' ------------------------------------------------------------------------------
' Initialization
' ------------------------------------------------------------------------------
Initialize:
DirB = %1111 'make stepper pins 4, 5, 6, 7 outputs
DirC = %1111 ' make stepper pins 8,9,10,11 outputs
speed = 0 'set starting speed
sAddrA = 0
saddrB = 0
' ------------------------------------------------------------------------------
' Program Code
' ------------------------------------------------------------------------------
Main: 
'
' intialize motors by stepping x steps in both directions
'
	FOR x = 1 TO 200 ' 1 rev forward
		GOSUB Step_FwdA
	NEXT
	PAUSE 200

	FOR x = 1 TO 200 ' 1 rev back
		GOSUB Step_RevA
	NEXT
	PAUSE 200


	FOR x = 1 TO 200 ' 1 rev forward
		GOSUB Step_FwdB
	NEXT
	PAUSE 200

	FOR x = 1 TO 200 ' 1 rev back
		GOSUB Step_RevB
	NEXT
	PAUSE 200


Step_Demo:

Again:
	PULSIN PulseA, 1, rcA
'	Debug "Pulse A", DEC ? rcA,cr
'	Debug "Pules B", DEC ? rcB,cr
	If rcA  = 0 THEN Again	' Wait for a pulse

	If rcA > 20 THEN Step_A
	GOTO Step_B
Step_A:
	if rcA > 30 then Step_CCWA

Step_CWA:
	GOSUB Step_FwdA ' do a step
	GOTO Step_Demo

Step_CCWA: 
	GOSUB Step_RevA
	GOTO Step_Demo

Step_B:
	if rcA > 10 then Step_CCWB

Step_CWB:
	GOSUB Step_FwdB ' do a step
	GOTO Step_Demo

Step_CCWB: 
	GOSUB Step_RevB
	GOTO Step_Demo


' ------------------------------------------------------------------------------
' Subroutines
' ------------------------------------------------------------------------------

Step_FwdA:
	sAddrA = sAddrA + 1 // 4 ' point to next step
	READ (Step1A + sAddrA), CoilsA ' output step data
'	PAUSE speed ' pause between steps
	RETURN

Step_RevA:
	sAddrA = sAddrA + 3 // 4 ' point to previous step
	READ (Step1A + sAddrA), CoilsA
'	PAUSE speed
	RETURN

Step_FwdB:
	sAddrB = sAddrB + 1 // 4 ' point to next step
	READ (Step1B + sAddrB), CoilsB ' output step data
'	PAUSE speed ' pause between steps
	RETURN

Step_RevB:
	sAddrB = sAddrB + 3 // 4 ' point to previous step
	READ (Step1B + sAddrB), CoilsB
'	PAUSE speed
	RETURN