' =========================================================================
'
'   File...... PWM.SXB
'   Purpose... Generate sawtooth wave with PWM instruction
'   Author.... (c) Parallax, Inc. -- All Rights Reserved
'   E-mail.... support@parallax.com
'   Started...
'   Updated... 29 OCT 2004
'
' =========================================================================


' -------------------------------------------------------------------------
' Program Description
' -------------------------------------------------------------------------
'
' PWM To Genrate RGB Colors From A RGB Led


' -------------------------------------------------------------------------
' Device Settings
' -------------------------------------------------------------------------

DEVICE          SX28, OSC4MHZ, TURBO, STACKX, OPTIONX
FREQ            4_000_000


' -------------------------------------------------------------------------
' IO Pins
' -------------------------------------------------------------------------

DACBLUE		VAR	RB.0			' output to RC network
DACRED		VAR	RB.1			' output to RC network
DACGREEN		VAR	RB.2			' output to RC network


' -------------------------------------------------------------------------
' Variables
' -------------------------------------------------------------------------

dutyA		VAR	Byte
dutyB		VAR	Byte
dutyC		VAR	Byte
dutyD		VAR	Byte
dutyE		VAR	Byte
dutyF		VAR	Byte


' =========================================================================
  PROGRAM Start
' =========================================================================


' -------------------------------------------------------------------------
' Program Code
' -------------------------------------------------------------------------

Start:
  FOR dutyA = 255 TO 0 STEP -1			'LoopC inside loopB inside loopA
  PWM DACBLUE, dutyA, 15
  
  FOR dutyB = 255 TO 0 STEP -1
  PWM DACGREEN, dutyB, 15  

  FOR dutyC = 255 TO 0 STEP -1
  PWM DACRED, dutyC, 15

  NEXT dutyC
  NEXT dutyB
  NEXT dutyA


'FOR dutyD = 0 TO 255 STEP 1
  'PWM DACRED, dutyD, 15
  'NEXT
 
'FOR dutyE = 0 TO 255 STEP 1
  'PWM DACBLUE, dutyE, 15
  'NEXT
  
'FOR dutyF = 0 TO 255 STEP 1
  'PWM DACGREEN, dutyF, 15
  'NEXT
  
  
  GOTO Start 