ServoControlWithPushbuttonsYourTurn.bs2

' {$STAMP BS2}
' {$PBASIC 2.5}
' ServoControlWithPushbuttonsYourTurn.bs2: The title says it all.
' IN4 moves servo right, IN3 moves servo left. Use pullup resistors.
pos VAR Word
delay CON 0 'Time of low pulse in ms, minus code (and PBASIC interpreter) overhead.
'Note delay is set to 0-this is because the DEBUG statement provides enough of a delay to remove the PAUSE.
'If we remove it, the delay must be set to ~8-10 ms or so.
'This is where bit-banging servo pulses is not a good idea-it's better to use a microcontroller
'with a built-in timer, such as the ATMega328p on the Arduino.
'The PIC on the Stamp might have a timer, but PBASIC might not let us use it.
stepval VAR Byte 'Amount to step the pos variable by per loop

hiLimit VAR Word
loLimit VAR Word 'Software position limits

DEBUG "Lower position limit: "
DEBUGIN DEC loLimit
DEBUG "Upper position limit: "
DEBUGIN DEC hiLimit
DEBUG "Step value: "
DEBUGIN DEC stepval

pos=750 'default position
DO
  PULSOUT 14, pos
  IF IN3=1 AND IN4=1 THEN
    'This if-clause left blank to prevent erratic behavior. (If a clause for "IN3=1 AND IN4=1" is not
    'used, then the Stamp will try to execute either the go-left or go-right behavior.)
  ENDIF

  IF IN3=0 THEN 'Higher values turn the servo towards the left.
    pos=pos+stepval
  ENDIF

  IF IN4=0 THEN
    pos=pos-stepval
  ENDIF

  IF pos<loLimit THEN
	    pos=loLimit
  ENDIF
  IF pos>hiLimit THEN
	    pos=hiLimit
  ENDIF

  PAUSE delay
  DEBUG HOME, "Position (higher=more left): ", DEC pos
LOOP