0+
0.0/5 from 0 reviews
Order by 16:00 for same day shipping 14 days return

GPIO Project 4 - Push button (digital/analog)

Beginner
30 Minuten
€167.09

In this project you will learn two ways to use a push button:

  1. Digital use : The pushbutton is connected to a GPIO pin of the Raspberry Pi and controls an LED via a Python program.
  2. Analog use : The push button is connected directly into a simple circuit to control an LED, without GPIO or programming intervention.

Digital Push Button

Connection diagram

  1. Connect the push button:
    • One side of the push button:
      • Connect to GPIO 17 (pin 11) .
      • Connect to GND (pin 6) .
    • The other side of the push button:
      • Connect to 3.3V (pin 1) .
  2. Connect the LED:
    • Long leg (anode) :
      • Connect this to GPIO 27 (pin 13) .
    • Short leg (cathode) :
      • Connect to GND (pin 6) .

Pinout Reference

GPIO

Pin #

Function

Connection

GPIO 17 Pin 11 Digital input Push button
GPIO 27 Pin 13 Digital output LED
GND Pin 6 Earth (Ground) Push button & LED

Python code in Thonny

  1. Write your code: Open the Thonny Python IDE and enter the following code:
from gpiozero import LED, Button
from signal import pause

# LED en drukknop koppelen aan GPIO-pinnen
led = LED(27)       # LED op GPIO 27
button = Button(17) # Drukknop op GPIO 17

# Actie koppelen: LED aan bij knop indrukken
button.when_pressed = led.on
button.when_released = led.off

print("Druk op de knop om de LED te bedienen!")
pause()  # Houd het programma actief

2. Save the file : Click File > Save As and name the file button_led_digital.py .

3. Run the script : Click the green Run button (▶) at the top of the Thonny interface.

How does it work?

  • Button(17) : Configures GPIO 17 as an input pin for the pushbutton.
  • when_pressed and when_released : Determines what happens when the button is pressed or released.
  • pause() : Keeps the script running until you manually stop it.

Result

  • Press the button: The LED turns on.
  • Release the button: The LED turns off.

Analog Usage

  1. Connect the push button:
    • One side of the push button:
      • Connect to the long leg (anode) of an LED.
    • The other side of the push button:
      • Connect to a 220Ω resistor , and connect the other side of the resistor to +3.3V (pin 1) .
  2. Connect the LED:
    • Short leg (cathode) of the LED is connected directly to GND (pin 6) .

Pinout Reference

Pin

Function

Connection

Pin 1 3.3V Power Supply One side of the push button
Pin 6 Earth (Ground) LED cathode

How does it work?

  • When you press the push button, you immediately close the circuit between the 3.3V power supply and the LED.
  • This turns on the LED without any GPIO or programming intervention.

Result

  • Press the button: The LED turns on.
  • Release the button: The LED turns off.

Experimenting

  1. Expanding digital use:
    • Let the LED flash as long as the button is pressed:
from gpiozero import LED, Button
from time import sleep

led = LED(27)
button = Button(17)

while True:
    if button.is_pressed:
        led.on()
        sleep(0.5)
        led.off()
        sleep(0.5)
    else:
        led.off()

2. Combining analog and digital:

  • Use one pushbutton for the analog circuit and a second pushbutton for digital control via GPIO.

After this project you can move on to the next project:

https:// electronicsforyou.com/project/gpio-project-5-ldr-introduction

Required products