Published May 14, 2017 © GPL3+

Push Button with Raspberry Pi

Quick Project to Interface Push Button with Raspberry Pi

BeginnerFull instructions provided30 minutes87,898

Things used in this project

Hardware components

Raspberry Pi

Push Button

LED

100 ohm Resistor

Breadboard (generic)

Jumper Wires

Story

Interfacing Push button with Raspberry Pi is very simple. In this project i will show you how to interface 4 pin push button switch with Raspberry Pi 2 and also connect one LED so that when button is pressed, LED will turn ON and on button release it will turns OFF.

Components

Push Button Basics

4 pin Push Button

Internal connections of pins:

Internal Connection of pins

There is direct connection between A and B, whether button is pressed of not. And same for C and D.

When button is pressed, A and C are getting shorted (actually all pins are getting shorted) and same way B and D are getting shorted.

So to use this push button as a switch, use either A-C pair or B-D pair or A-D or B-C.

Hardware Setup

The Button is wired in such a way that when it is pressed, it will connect GPIO 23 to the Ground(GND).

In the code (check below in code section),

GPIO.setup(23, GPIO.IN, pull_up_down=GPIO.PUD_UP)

means GPIO 23 is normally pulled up to 3.3V. So that when you read the input value using GPIO.input , it will return False if the button is pressed.

Pull Up Resistor Concept

1 / 2 • When Button is not Pressed

Each GPIO pin in Raspberry Pi has software configurable pull-up and pull-down resistors. When using a GPIO pin as an input, you can configure these resistors so that one or either or neither of the resistors is enabled, using the optional pull_up_down parameter to GPIO.setup

If it is set to GPIO.PUD_UP , the pull-up resistor is enabled; if it is set to GPIO.PUD_DOWN , the pull-down resistor is enabled.

After running the code, when you push the Button LED should turn ON and in terminal window you will see the text "Button Pressed...". If not then check you code and connections and try again.

Video

Summery of the project:

Summery of the Project

Code

button.py

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

GPIO.setup(23, GPIO.IN, pull_up_down=GPIO.PUD_UP)#Button to GPIO23
GPIO.setup(24, GPIO.OUT)  #LED to GPIO24

try:
    while True:
         button_state = GPIO.input(23)
         if button_state == False:
             GPIO.output(24, True)
             print('Button Pressed...')
             time.sleep(0.2)
         else:
             GPIO.output(24, False)
except:
    GPIO.cleanup()

Credits

Hardik Rathod

1 project • 33 followers

Push Button with Raspberry Pi

Things used in this project

Hardware components

Story

Push Button Basics

Hardware Setup

Pull Up Resistor Concept

Video

Schematics

Schematic

Code

button.py

Credits

Hardik Rathod

Comments

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Push Button with Raspberry Pi

Push Button with Raspberry Pi

Things used in this project

Hardware components

Story

Push Button Basics

Hardware Setup

Pull Up Resistor Concept

Video

Schematics

Schematic

Code

button.py

Credits

Hardik Rathod

Comments

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