BuildBrighton Element14 hackerspace challenge - Cube reader

Cubes contain resistors on each face. These are soldered to magnets which are orientated on their sides and poke through slits in the cube face. This prevents them from falling out of the cube and causuing a hazard.

The cube readers simply contain 2 more magnets with wires that head off to the Arduino.

The magnets polarity on each face is oriented the same way, same on the reader. This means that we get a simple method of rejecting cubes inserted upside down - the magnets repel :-)

The reason for using magnets is that is gives a nice tactile feedback that the cube is placed correctly. It also means we get a strong connection.

The Arduino has a simple voltage divider leadng to an analog pin. The code scans each reader in turn looking for a change in value from 0. When it detects a value withing a buffer range it drags the required .wav from the SD card and plays it. At the moment I am using boggo +/- 5% resistors on the divider. These will have to go to precision resistors for all 7 cubes.

That is it, costs peanuts and is very simple. There may be environmental issues to deal with regarding dirty magnets. For a proof of concepet it works well.

Also in this design are eject holes. These are for small pusher dowels connected to a servo. After the child has successfully spelt their word, the system will eject all cubes automatically. The cubes will disengage from the magnet coupling and fall down the angled reader base.

Category:

Howto & Style

Tags:

• education
• laser
• arduino
• speech
• hackerspace
• buildbrighton
• hackerspace_challenge
• phonics
• waveshield