1.7 Piggy Bank

In this project we will use Speed sensor module, Raspberry Pi and Scratch to make a Piggy Bank.

Place a piece of paper in the middle of the Speed sensor module and you will see a coin fall into the Piggy Bank on the stage.

../_images/1.7_header.png

Required Components

In this project, we need the following components.

../_images/1.7_component.png

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

Name

ITEMS IN THIS KIT

LINK

Raphael Kit

337

Raphael Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION

PURCHASE LINK

GPIO Extension Board

BUY

Breadboard

BUY

Jumper Wires

BUY

Speed Sensor Module

-

Build the Circuit

../_images/1.7_fritzing.png

Load the Code and See What Happens

Load the code file (1.7_piggy_bank.sb3) to Scratch 3.

The 2 terminals in the middle of the speed sensor, one is to send light, one is to receive light; if you put a piece of paper in the middle to isolate the light transmission, thus the speed sensor will output a high level. At this point Scratch receives the high level, then switch the costumes of the sprite and you will see a coin fall into the Piggy Bank on the stage.

Tips on Sprite

Select Sprite1 and click Costumes in the top left corner; upload piggybank1.png, piggybank2.png and piggybank3.png from the ~/raphael-kit/scratch/picture path via the Upload Costume button; delete the default 2 costumes, and rename the sprite to piggybank.

../_images/1.7_photoInterrupter1.png

Tips on Codes

../_images/1.7_code2.png

When pin17 is low (no coins are put in), switch the sprite’s costume to piggybank1.

../_images/1.7_code3.png

When pin17 is high (a coin is put in), switch the sprite’s costume to piggybank2, and after 0.5s switch to piggybank3, so that we can see a coin falling into the Piggy Bank on the stage.