' =========================================================================
'   File....... StepperSXB
'   Purpose.... Run a bipolar stepper motor
'   Author..... David Mcanulty
'   E-mail..... stepperSX28program@hellspark.com
'   Started.... 01-16-2010
'   Updated.... Never
' =========================================================================

' -----[ Program Description ]---------------------------------------------
'
' Runs a stepper motor provided to me by scott
'
'------{ Device Settings ]-------------------------------------------------

DEVICE         SX28,TURBO,BANKS8,OSCHS3,SYNC,OPTIONX
FREQ           50_000_000
ID             "STEPPER"

' -----[ I/O Definitions ]-------------------------------------------------

Coils          VAR     RB			' RB.0->RB.3 connect to L293D chip
Speed          VAR     RA.0                  ' Pot circuit IO (speed control)
LtMode         VAR     RA.1                  ' mode select input


' -----[ Constants ]-------------------------------------------------------

LoSpeed        CON     1                      ' lo end of POT reading
'Scale         CON     $0163                   ' 1.3868 with */
Scale          CON     $0030                   ' 1.3868 with */

' -----[ Variables ]-------------------------------------------------------

rawSpd         VAR     Word                    ' speed input from POT
delay          VAR     Word                    ' time between patterns
btnVar         VAR     Byte                    ' workspace for BUTTON
modeSelect     VAR     Byte                    ' selected mode
maxSteps       VAR     Byte                    ' offset into patterns
rndVal         VAR     Byte                    ' workspace for RANDOM
testPot		   VAR     Byte                    ' 1 for POT testing
idx		      VAR     Byte			' Index for subs

' -----[ Initialization ]-------------------------------------------------
PROGRAM Start
watch coils, 4, UBIN
watch rawSpd, 16, UDEC
watch Speed, 8, UDEC
watch LtMode, 1, UBIN
watch ModeSelect, 8, UDEC
watch maxSteps, 8, UDEC
watch rndVal, 8, UDEC 
watch delay, 16, UDEC
watch idx, 8, UDEC

' -----[Subs ]------------------------------------------------------------
Read_Speed           SUB     0
ModeClockwise        SUB     0
ModeCounterclockwise SUB     0

' -----[ Program Code ]----------------------------------------------------

Start:     '########
  coils =  %00000000       ' start with outputs off
  Tris_A = %0011				' Make ra.0 and ra.1 inputs for pot
  Tris_B = %11000000       ' make rb.0 -> rb.5 outputs
  idx = 1
  TestPot = 0 		         ' 1 for POT testing
  IF TestPot = 1 THEN      ' for reading raw pot value
     DO
      GOSUB Read_Speed
      PAUSE 50
    LOOP
  ENDIF
 
Main:
 GOSUB Read_Speed                               ' read speed pot
  'delay = (rawSpd - LoSpeed) */ Scale + 50     ' calc delay (50-1000 ms)
  delay = rawSpd - LoSpeed                      ' calc delay (50-1000 ms)
  delay = delay */ Scale                        ' calc delay (50-1000 ms)
  'delay = delay + 50                           ' calc delay (50-1000 ms)
  'delay = 1000
  PAUSE delay                                   ' wait between patterns

Switch_Check:
  ''BUTTON LtMode,        0,   255,    0,    btnVar,           0, Show
  ''BUTTON    Pin,DownState, Delay, Rate, Workspace, TargetState, Address 
  IF LtMode = 0 THEN
     Pause 10
     IF ltMode = 0 THEN
        'modeSelect = modeSelect + 1 // 5               ' yes, update mode var
        modeSelect = modeSelect + 1 	                ' yes, update mode var
        modeSelect = modeSelect // 5                    ' yes, update mode var
     ENDIF
  ENDIF
  'modeSelect = 0
Show:

  Branch modeSelect, ModeClockwise, ModeCounterclockwise
  GOTO Show

  END


' -----[ Gosubs ]-----------------------------------------------------

Read_Speed:
  HIGH Speed                                    ' charge cap
  PAUSE 1                                       ' for 1 millisecond
  RCTIME Speed, 1, rawSpd                       ' read the Pot
  RETURN

ModeClockwise:
  READ PatternClockwise, maxSteps               ' get steps in sequence
  IF idx <= maxSteps THEN                       ' check idx range
    READ PatternClockwise + idx, coils          ' get step pattern
    INC idx                                     ' point to next step
    PAUSE delay
  ELSE
    idx = 1                                     ' reset idx if needed
  ENDIF
  GOTO Show

ModeCounterclockwise:
  READ PatternCounterclockwise, maxSteps        ' get steps in sequence
  IF idx <= maxSteps THEN                       ' check idx range
    READ PatternCounterclockwise + idx, coils   ' get step pattern
    INC idx                                     ' point to next step
    PAUSE delay
  ELSE
    idx = 1                                     ' reset idx if needed
  ENDIF
  GOTO Show


' -----[ EEPROM Data ]-----------------------------------------------------

PatternClockwise:
   DATA    4
           '111222  COIL #
	   'abeabe  Terminal A | Terminal B | Enable  
   DATA    %101000 '1 
   DATA    %000101 '2
   DATA    %011000 '3
   DATA    %000011 '4
PatternCounterclockwise:
   DATA    4           
           '111222  COIL #
	   'abeabe  Terminal A | Terminal B | Enable  
   DATA    %101101 '1
   DATA    %101011 '2
   DATA    %011011 '3
   DATA    %011101 '4