122-28176 Parallax Inc, 122-28176 Datasheet - Page 19

• 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

BuzzerDur CON
' -----[ Initialization ]--------------------------------------------------
OUTPUT LED
OUTPUT Buzzer
' -----[ Main Routine ]----------------------------------------------------
DO
LOOP
' ******** Read Pushbutton
PBVal = PB
' ******** Display pushbutton value
DEBUG CLS, "Pushbutton Value = ", DEC PBVal,CR
' ******** Set LED to pushbutton value
LED = PBVal
' ******** Measure Photoresistor
HIGH Photo
PAUSE 10
RCTIME Photo, 1, PhotoVal
' ******** Display photoresistor value
DEBUG "Photo RC Time Value = ", DEC PhotoVal,CR
' ******** Sound buzzer at set duration at frequency of PhotoVal
FREQOUT Buzzer,BuzzerDur,PhotoVal
' ******** 1/4 seconds delay
PAUSE 250
√
√
Test the circuit by pressing the pushbutton and varying the light falling on the
photoresistor.
If your circuit does not operate properly, verify your circuit connections and
code.
o
o
o
o
250
When the button is pressed does the state of the pushbutton change from
1 to 0 in the Debug Terminal?
When the button is pressed does the LED change from on to off?
When the sensor is darkened does the photoresistor RC time value
change in the Debug Terminal?
Does the frequency output of the buzzer change in relation to the
photoresistor's RC time value? Note that the buzzer has a very limited
frequency response range.
' Constant for duration of tone for buzzer
' Set LED pin to be an output
' Set Buzzer pin to be an output
' Read Pushbutton value and assign to PBVal
' Display Pushbutton value
' Set LED based on Pushbutton value
' Charge photoresistor's RC network Capacitor
' Allow 10 milliseconds to charge fully
' Measure discharge time through photoresistor
' 1/4 second pause
' Loop back to DO to repeat continuously
Chapter 1: Process Control and Flowcharts · Page 9