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A great starter hardware project using the Raspberry Pi is hooking up a simple tactile switch to the Raspberry GPIO and detecting button presses in Python. This guide will guide you through setting up the circuit with the Raspberry Pi and reading the state of the button in Python.
How does a GPIO function work on a Raspberry Pi?
A GPIO event in the Raspberry Pi Python GPIO library works by calling a Python function whenever an event is triggered. Such a function is called a callback function.
What’s the input pin on a Raspberry Pi?
We connect one side of the switch to an input pin on the Raspberry Pi, in this case we use pin 10. The other side of the switch we connect to 3.3V on pin 1 using a resistor. The resistor is used as a current limiting resistor to protect our input pin by limiting the amount of current that can flow.
Which is the input pin 0V or 3.3V?
The idea is that the input pin will be low (0V) when the button is not pushed. When the button is pushed it will connect the pin to 3.3V and change the state to high (3.3V). When you hook up the circuit you can use the following reference to diagram to find the correct pin numbers.
What can I do with my Raspberry Pi?
You could send a tweet or turn on a LED. We will need the following tools to complete the project: Connecting the Raspberry Pi’s general purpose input output ports (GPIO) to a momentary tactile push button switch is a fairly simple circuit. We connect one side of the switch to an input pin on the Raspberry Pi, in this case we use pin 10.
If you want to use additional parameters you can set the button instance manually: You cannot pass a parameter to a callback function. You need separate functions for each callback. Thanks for contributing an answer to Raspberry Pi Stack Exchange!
How to use mandatory parameters in gpiozero button?
It is possible to use parameters with callback functions. See e.g. Documentation for button.when_pressed This can be set to a function which accepts no (mandatory) parameters, or a Python function which accepts a single mandatory parameter (with as many optional parameters as you like).
What do you use a breadboard for Raspberry Pi?
In the old days, people would either solder wire components together on an actual breadboard, or they’d wrap wires together around nails in a pinboard. For a lot of Raspberry Pi fans, using a breadboard is part of life.
How do you light a led on a Raspberry Pi?
This complete diagram uses the power and ground pins from a Raspberry Pi to light up an LED. Take a female-to-male jumper lead (the colour of the wire doesn’t matter) and connect the female end to a 5V pin on the Raspberry Pi. Place the male end of the lead into a hole on the red rail on the breadboard.