ex22 - throb.bs2

proteus得一些经典例子

' {$STAMP BS2}
' ==============================================================================
'
' File...... Ex22 - Throb.BS2
' Purpose... Output a variable voltage with PWM
' Author.... Parallax
' E-mail.... [e-mail]
' Started...
' Updated... 01 MAY 2002
'
'
' ==============================================================================
' ------------------------------------------------------------------------------
' Program Description
' ------------------------------------------------------------------------------
' This program demonstrates how the PWM command can be used with an opamp
' buffer to create a variable voltage output.
' ------------------------------------------------------------------------------
' I/O Definitions
' ------------------------------------------------------------------------------
D2Aout CON 0 ' analog out pin
' ------------------------------------------------------------------------------
' Constants
' ------------------------------------------------------------------------------
OnTime CON 10 ' 10 milliseconds, BS2
'OnTime CON 25 ' BS2sx
'OnTime CON 15 ' BS2p
' ------------------------------------------------------------------------------
' Variables
' ------------------------------------------------------------------------------
level VAR Byte ' analog level
' ------------------------------------------------------------------------------
' Program Code
' ------------------------------------------------------------------------------
Main:

PWM D2Aout, 0, OnTime
PAUSE 2
PWM D2Aout, 128, OnTime
PAUSE 2
PWM D2Aout, 255, OnTime
PAUSE 2

FOR level = 0 TO 255 ' increase voltage to LED
PWM D2Aout, level, OnTime
NEXT
PAUSE 250
FOR level = 255 TO 0 ' decrease voltage to LED
PWM D2Aout, level, OnTime
NEXT
GOTO Main ' do it again