What is a Push Button?
A push button is a momentarily activated button. When the button mechanism is fully depressed an internal electrical connection is made and this newly made connection can be read as the activation of the button.
Setting up Node-Red
Start Node-Red and navigate to 127.0.0.1:1880. Drag a Raspberry Pi input node and a Debug node into the flow area.
Double click on the Raspberry Pi input node to open its configuration menu. Set the Pin to GPIO25. Set Resistor? to pulldown. You can Name the node anything, I chose “button”.
The debug node can be left with it’s default settings, wire the button node to the debug node and deploy the flow.
If everything has been put together correctly you should see the number under the button node in the Node-Red flow change from a 0 to a 1 when the button is activated and from 1 to 0 when the button is deactivated. You should also be able to see a record of the button activation in the debug tab of Node-Red.