ex04 - ping pong.bs2

proteus得一些经典例子

' {$STAMP BS2}
' ==============================================================================
'
' File...... Ex04 - Ping Pong.BS2
' Purpose... Ping-Pong LED Display
' Author.... Parallax
' E-mail.... [e-mail]
' Started...
' Updated... 01 MAY 2002
'
'
' ==============================================================================
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' Program Description
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' "Ping-Pongs" an LED (one of eight).
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' I/O Definitions
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LEDs VAR OutL ' LEDs on Pins 0 - 7
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' Constants
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DelayTime CON 100 ' delay time in milliseconds
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' Initialization
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Initialize:
DirL = %11111111 ' make all pins outputs
LEDs = %00000001 ' start with one LED on (pin 0)
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' Program Code
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Go_Forward:
PAUSE DelayTime ' show the LED
LEDs = LEDs << 1 ' shift lit LED to the left
IF (LEDs = %10000000) THEN Go_Reverse ' test for final position
GOTO Go_Forward ' continue in this direction
Go_Reverse:
PAUSE DelayTime ' show the LED
LEDs = LEDs >> 1 ' shift lit LED to the right
IF (LEDs = %00000001) THEN Go_Forward ' test for final position
GOTO Go_Reverse ' continue in this direction
END