1. Prepare the Sound Board

• Solder the supplied header pins onto the Sound Board. Always make sure you solder in a well-ventilated area or outdoors.

2. Load your sounds

You can create your own sounds, the board can play either uncompressed WAV files or compressed audio files in the Ogg Vorbis format. We recommend using Ogg Vorbis files for longer audio files. The decoding hardware can handle any bit/sample rate and either mono or stereo audio. Audacity is free and a great way to create and edit your own sounds.

The Sound Board has 11 trigger pins (numbered #0 to #10), which means you can connect up to 11 buttons or switches, with each one triggering a different audio file. You can control how the sounds are triggered and which pins trigger them by how you name each file. Depending on the project you may need to play audio in different ways:

Basic Trigger – The audio file will play when the matching trigger pin is connected to ground momentarily. Name the file TnnX.WAV (or.OGG) where “X” is the pin number you want to allocate the sound to.

Hold Looping Trigger -The audio will play while the trigger pin is held low, it will loop until the pin is released. Name the file TnnXHOLDL.WAV (or .OGG)

Latching Loop Trigger – The audio will start playing when the button is pressed once and repeats until the button is pressed again. Name the file TnnXLATCH.WAV (or .OGG) 

Play Next Trigger – Have up to 10 files play one after the other by naming them TnnNEXTX.WAV up to TnnNEXTX.WAV (or .OGG). It will start with #0 and each time the button is momentarily pressed, it will play the next sound until it gets through all of them, then it will go back to #0.

Play Random Trigger – Like the Play Next trigger, but it will play up to 10 files in random order TnnRANDX.WAV up to TnnRANDX.WAV (or .OGG) every time the button is pressed momentarily.

For this project we’ll use the Basic Trigger, renaming our files to T00, T01, T02 etc. To ensure that our pressure pad steps don’t get set off repeatedly, we have added 3 seconds of silence to the end of each audio file – You will most likely want to do the same.

Once you have created and named your sounds appropriately, do the following:

1. Connect the Sound Board to a computer using a micro USB cable. It should appear as a removable disk.
2. Drag and drop your audio files onto the board, just like a USB flash drive.

3. Build the steps

To trigger your sounds as someone walks up or down a set of stairs, we will create a series of pressure pad switches using plywood, packaging foam and adhesive foil tape. These complete a simple circuit by contacting two foil surfaces when someone stands on them, squashing the foam that normally keeps them apart.

• Measure the top face of one of the steps on your stairs and cut rectangular plywood pieces to fit that surface leaving enough room around the plywood so it can easily move up and down. These will be the top plywood layer.

• Cut another set of slightly smaller rectangular plywood pieces, one for each of your previous pieces. These will be the bottom plywood layer.

• If you wish to paint or decorate your larger top plywood pieces (e.g. to make them look like a piano), then this is a good point in the process to do this.

• Stick adhesive aluminium foil tape onto both plywood pieces – as shown:

• Use a combination of a piece of duct tape and a piece of foil tape, to create a conductive connection between your foil strips. The sticky sides of the foil and duct tape should be against each other.

• Cut thin strips of packaging foam to create a foam border around the edge of your larger top plywood pieces.
• Glue these in place using a suitable multipurpose adhesive, double-sided tape (or use adhesive-backed foam if you have some).

• Measure and cut lengths of twin core cable so that each of your plywood pressure pads can be wired back to wherever you intend to locate your Sound Board, speaker and battery pack. It pays to leave an extra 50cm or so of cable, just in case. Each of these cables will probably be a different length depending on the location of the specific step on your stairs. You may also find it useful to number each step to avoid later confusion.
• Separate the two cable cores at one end of each cut wire length and strip the ends. Use foil tape to attach one bare cable to the foil contact on the large top plywood piece for each pressure pad and one on each of the smaller bottom plywood pieces. 

• Place your smaller plywood pieces on the stairs with the larger ones on top, so that when someone steps onto them, the top piece compresses the foam, creating an electrical connection between the top and bottom foil sections.

You can test the effectiveness of your cable connections using a multimeter (in continuity test mode) by connecting it across the end of your two cables to check for continuity when the two foil sections are in contact.

4. Build the circuit

Each of the Sound Board sounds is triggered when one of its trigger pins is connected to the board’s ground pin.

• Mount the Sound Board onto a breadboard, then for each pressure pad step you have made, connect one of the wire contacts to its own trigger pin on the Sound Board.
• Connect the remaining wire contacts for each pressure pad to a common ground track on your breadboard.
• Connect the red positive wire from your battery holder to the board’s Vin pin, and the black negative wire to the GND pin.
• Add some batteries to power it up.
• Connect a powered speaker to the audio jack socket on the Sound Board using a 3.5mm jack lead.

You’re now ready test your musicals stairs!