User Guide

191
Figure 1. Basic button input
You can use a push button for this project, or a standard doorbell
switch. Doorbells usually have two screw terminals inside, which
make electrical connections by tightly holding wires onto metal
contacts. To connect a wire to a terminal:
1. Loosen the screw by turning it counterclockwise.
2. Strip 25 mm–35 mm of insulation from the wire.
3. Wrap the exposed part around the screw.
4. Tighten the screw by turning it in a clockwise
direction.
Repeat the process for the other terminal.
The direction that you connect the wires to your circuit does not
matter.
1. Connect one wire from the bell to GPIO2 (pin 3).
2. Connect the other wire from the doorbell to one leg
of the 330 Ω resistor.
3. Connect the other leg of the resistor to a ground on
the GPIO header.