2.3 Service Bell

For this project we used a microswitch and an active buzzer to create a service bell. Tap the switch and the buzzer makes a sound.

Micro Switch is also a 3-pin device, the sequence of the 3 pins are C (common pin), NO (normally open) and NC (normally closed).

When the micro switch is not pressed, 1 (C) and 3 (NC) are connected together, when pressed 1 (C) and 2 (NO) are connected together.

img_micro_switch

Bill of Materials

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name

ITEMS IN THIS KIT

LINK

Kepler Kit

450+

Kepler Kit

You can also buy them separately from the links below.

SN

COMPONENT

QUANTITY

LINK

1

Raspberry Pi Pico W

1

BUY

2

Micro USB Cable

1

3

Breadboard

1

BUY

4

Wires

Several

BUY

5

Resistor

2(1KΩ, 10KΩ)

BUY

6

Capacitor

1(104)

BUY

7

Micro Switch

1

8

Transistor

1(S8050)

BUY

9

Active Buzzer

1

Wiring

service_bell0

  • By default, pins 1 and 3 of the Micro Switch are connected together and GP14 is low. When the Micro Switch is pressed, GP14 is high.

  • GP15 outputs high to make the buzzer sound.

Code

Note

  • You can refer to the image below to write code by dragging and dropping.

  • Import 2.3_service_bell.png from the path of kepler-kit-main\piper. For detailed tutorials, please refer to Import the Code.

service_bell

After connecting Pico W, click the Start button and the code starts to run. Tap the switch and the buzzer makes a sound.

Note

This project code is exactly the same as the previous project 2.2 Button.