Touch Board

Create a custom Touch Board project by playing your own audio files

One of the Touch Board’s defining features is to play music, a recording, or a sound when touching the board’s electrodes, acting as an MP3 player, out of the box! The Touch Board comes pre-loaded with an audio guide to help you familiarize yourself with all its features. The audio guide is stored as twelve MP3 files on the board’s microSD card. Changing these files is straightforward. There is no programming required!

The key is to follow the appropriate naming structure for your MP3s to ensure each electrode will trigger the right sound. All you need is a microSD card reader and some great sounds!

You will need:

• 1 x Touch Board
• 1 x USB Micro B to USB A or USB C (depending on your computer’s USB port type)
• 1 x Computer running Mac OS, Windows, or Linux
• 1x MicroSD card reader

Step 1 Prepare the MP3 files

The first step is to select the sounds that you want your Touch Board to play. You may wish to record custom sounds or already have a library of audio to choose from. YouTube is an excellent resource for finding MP3 music (via a download tool) as is freesound.org. Make sure that each file is an MP3 file. If they aren’t in MP3 format, you can always use an online MP3 converter. Note that the file size is important; it takes longer to load if it’s too large.

To use the MP3 files on the Touch Board, you need to rename them. The Touch Board follows a naming structure, where TRACK000.mp3 is for electrode E0, TRACK001.mp3 for E1, and so on, up to TRACK011.mp3 for E11. You’ll see “E0” through “E11” marked on the edge of your Touch Board near the gold electrodes.

In this example, we have two tracks that we want to use: “Bleat.mp3” and “Bluejay.mp3”. We want to use them with the first two electrodes, E0 and E1. So we rename the tracks to TRACK000.mp3 and TRACK001.mp3.

Step 2 Copy the files onto the Touch Board

Take the microSD card out of the Touch Board by pushing it in. It should pop out.

Put it inside the microSD card reader and put the reader inside your computer. The SD card should show up as “TB Audio.” Have a look inside the folder. You will see all multiple files, including the audio files named TRACK000.mp3, TRACK001.mp3, and so on.

Copy-paste the new sounds onto the SD card, simultaneously removing the old TRACK000.mp3, TRACK001.mp3. Don’t worry. Once you have finished copying the files, remove the SD card from your computer.

Step 3 Test the new tracks

Pop the microSD card back into the Touch Board, connect some speakers or headphones to the Touch Board, and turn the Touch Board back on. Try touching electrode E0 and E1. You should hear the new track for each electrode!

Step 4 Next steps

Now that you know how to change the audio file for each electrode on the Touch Board, you can get creative and connect all sorts of conductive materials to the Touch Board’s electrodes. You can use Electric Paint to paint your very own sensors and give an audiobook a new interpretation.

If you want to edit a music file, we recommend the app Audacity. You can use it to trim and adjust the amplitude of a file.

Use Electric Paint to cold solder your board onto almost any material

Cold soldering is an excellent alternative to soldering and doesn’t require a soldering iron or soldering station. Instead, all you need is some Electric Paint! This tutorial demonstrates how to cold solder with our electrodes stencil and the Touch Board and shows you how to cold solder onto other materials!

We also provide a template to easily print out the pitch of the Touch Board or Pi Cap’s electrodes.

You will need:

• 1 x Touch Board
• Electric Paint 10ml, 50ml or 1l

Touch Board electrode spacing

If you want to connect to a number of sensors printed or painted onto a surface, getting the spacing between the sensors is important. If you bridge between the two sensors (because your painted lines are too wide or mis-aligned) those sensors won’t function. Don’t worry! You won’t break your board. It just won’t register anything until the electrical connection between those two electrodes is broken. If you’ve smudged Electric Paint across the electrodes, no problem. Just clean with soap and water.

You can paint your own lines, but to make things easier, we have also designed a stencil, which you can download here. If you don’t know how to prepare the stencil, you can follow our stencil tutorial to learn how to do this.

Once the stencil is ready, align your Touch Board to the Electric Paint traces you have applied.

Step 2 Cold solder

To cold solder, all you have to do is carefully squeeze a droplet of Electric Paint into each electrode that you want to connect to the paint beneath. When you are done, leave the paint to dry. The Electric Paint will act as a conductor and as a glue. That’s it, that’s how you cold solder!

Step 3 drying

Be careful not to move the Touch Board while drying. Otherwise, you risk smudging the paint and shorting the electrodes. Shorting the electrodes will not break the board, but you will need to clean it before you can use it again.

Step 4 Cold solder onto other materials

You can cold solder with Electric Paint to paper and onto other materials, for example, copper tape. This is useful for quick prototyping or when you need to securely attach your board to other conductors.