122-28176 Parallax Inc, 122-28176 Datasheet - Page 23

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

If you said the LED would blink on for ½ second when the button is pressed, and not at
all when not pressed, you would be correct.
Example Program: ConditionalLEDBlink.bs2
' -----[ Title ]-----------------------------------------------------------
' Process Control - ConditionalLEDBlink.bs2
' Blinks the LED based on state of Pushbutton
' {$STAMP BS2}
' {$PBASIC 2.5}
' -----[ Declarations ]----------------------------------------------------
Photo
LED
Buzzer
PB
PBVal
PhotoVal
BuzzerDur CON
' -----[ Main Routine ]----------------------------------------------------
DO
LOOP
Code Discussion
The
program will execute the code within the block if true or skip over it if false.
' ******** Read Pushbutton
PBVal = PB
' ******** Display Pushbutton value
DEBUG CLS,"Pushbutton value = ", DEC PBVal,CR
' ******** Button Pressed Conditional and Code
IF (PBVal = 0) THEN
ENDIF
' ******** 1/4 second pause
PAUSE 250
√
IF…THEN…ENDIF
Enter, save and run ConditionalLEDBlink.bs2.
HIGH LED
PAUSE 500
LOW LED
PIN
PIN
PIN
PIN
VAR
VAR
10
5
10
13
Bit
Word
250
block is used to test the condition. Based on the result, the
' Alias for photo resistor circuit on P0
' Alias for LED on P5
' Alias for buzzer on P10
' Alias for pushbutton on P13
' Bit variable to hold pushbutton value
' Word variable to hold RC Time value
' Constant for duration of tone for buzzer
' Read Pushbutton Value and assign to PBVal
' If pushbutton pressed is true then,
' blink the LED
' Loop back to DO to repeat continuously
Chapter 1: Process Control and Flowcharts · Page 13