Button press detection in Raspberry Pi - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the GPIO library.

Raspberry Pi

import [1]

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Atime

BRPi.GPIO

Cgpiozero

Dos

Attempts:

3 left

💡 Hint

Common Mistakes

Importing 'time' instead of the GPIO library.

Using 'os' which is unrelated to GPIO control.

We use RPi.GPIO to control GPIO pins on Raspberry Pi.

2fill in blank

medium

Complete the code to set the GPIO mode to BCM numbering.

Raspberry Pi

GPIO.setmode([1])

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AGPIO.BCM

BGPIO.BOARD

CGPIO.OUT

DGPIO.IN

Attempts:

3 left

💡 Hint

Common Mistakes

Using GPIO.BOARD which refers to physical pin numbers.

Using GPIO.OUT or GPIO.IN which are for pin direction.

BCM mode uses the Broadcom chip pin numbers.

3fill in blank

hard

Fix the error in setting up pin 17 as input with pull-up resistor.

Raspberry Pi

GPIO.setup(17, [1], pull_up_down=GPIO.PUD_UP)

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AGPIO.IN

BGPIO.PUD_DOWN

CGPIO.OUT

DGPIO.PUD_OFF

Attempts:

3 left

💡 Hint

Common Mistakes

Using GPIO.OUT instead of GPIO.IN.

Confusing pull-up/down constants with pin direction.

Pin 17 must be set as input to detect button presses.

4fill in blank

hard

Fill both blanks to read the button state and print if pressed.

Raspberry Pi

button_state = GPIO.input([1])
if button_state == [2]:
    print('Button pressed!')

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A17

BGPIO.LOW

CGPIO.HIGH

D18

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for GPIO.HIGH instead of GPIO.LOW.

Using wrong pin number like 18.

We read pin 17 and check if it is LOW because the button pulls the pin to ground when pressed.

5fill in blank

hard

Fill all three blanks to set up a button press event detection with a callback.

Raspberry Pi

def button_callback(channel):
    print('Button was pressed!')

GPIO.setup([1], GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.add_event_detect([2], GPIO.FALLING, callback=[3], bouncetime=200)

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A17

Bbutton_callback

CGPIO.RISING

DGPIO.FALLING

Attempts:

3 left

💡 Hint

Common Mistakes

Using GPIO.RISING instead of GPIO.FALLING for button press.

Using different pin numbers in setup and event detection.

Not passing the callback function correctly.

Pin 17 is set up as input with pull-up. Event detection triggers on falling edge (button press) and calls button_callback.