Freenove Ultimate Starter Kit User Manual

63
Chapter 2 Button & LED
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Python Code 2.1.1 ButtonLED
First, observe the project result, then analyze the code.
1. Use cd command to enter 01.1.1_btnLED directory of Python code.
cd ~/Freenove_Ultimate_Starter_Kit_for_Raspberry_Pi/Code/Python_Code/02.1.1_ButtonLED
2. Use Python command to execute btnLED.py.
python ButtonLED.py
Later, the terminal window continue to print out the characters “led off…”, press the button, then LED is turned
on and then terminal window print out the "led on…". Release the button, then LED is turned off and then
terminal window print out the "led off…". You can press "Ctrl+C" to terminate the program.
The following is the program code:
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im port RPi. GPIO as GPIO
ledPin = 11 # define the ledPin
buttonPin = 12 # define the buttonPin
def setup():
p rint ('Program is starting...')
GPIO. setmode(GPIO.BOARD) # Numbers GPIOs by physical location
GPIO. setup(ledPin, GPIO. OUT) # Set ledPin's mode is output
GPIO. setup(buttonPin, GPIO. IN, pull_up_down=GPIO.PUD_UP) # Set buttonPin's mode is
input, and pull up to high level(3.3V)
def loop():
w hile Tr ue:
if GPIO.input(buttonPin)==GPIO.LOW:
GPIO.output(ledPin,GPIO.HIGH)
print ('led on ...')
else :
GPIO.output(ledPin,GPIO.LOW)
print ('led off ...')
def destroy():
GPIO. output(ledPin, GPIO. LOW) # led off
GPIO. cleanup() # Release resource
if __name__ == '__main__': # Program start from here
setup()
try:
loop()
e xcept KeyboardInterrupt: # When 'Ctrl+C' is pressed, the subprogram destroy() will
be executed.
destroy()

Freenove Ultimate Starter Kit Specifications

General

Brand	Freenove
Model	Ultimate Starter Kit
Category	Single board computers
Language	English