- What is the Felt/Capacitive Piano?
It is a soft circuit device that acts as a makeshift piano by using the idea of capacitive touch to create output. In this case, the output would be a sound/tone similar to that produced by a piano. We wanted to share such a product to explore how soft circuits can be combined with musical concepts that can dwell into a myriad of soft circuit devices and wearables and as well a method of creating music.
- Materials Used & Where to Find Them
| Black & White Felt |
Michaels, Dollarama |
| Conductive Fabric |
Class kit, Creatron Inc |
| Conductive Thread |
Class kit, Creatron Inc |
| LED lights |
Class kit, Creatron Inc |
| Resistors |
Class kit, Creatron Inc |
| HeatnBond Lite Iron-On Adhesive |
Michaels, Amazon |
| CPX |
Class kit, Creatron Inc |
With the black felt, cut a rectangle for the base of the piano. With the white felt, cut smaller rectangles for the keys.
First, cut out the size you need for the keys. Then, use an iron to heat and bond the adhesive to the bottom of the keys. You can also use glue or regular thread to do this.
Peel off the sticker and use the HeatnBond Lite Iron-On Adhesive in the back of the fabric to glue the white keys onto the piano.
Use an iron to glue the now adhesive side of the keys onto the base of the piano.
Cut smaller pieces of conductive fabric and glue them either using the same HeatnBond Lite Iron-On Adhesive method or using regular glue or non-conductive thread. Add LED Lights on top of each key, either poking them through or using a regular thread. (The conductive thread will be used when adding the CPX!)
After writing your own code and making a circuit diagram, place the CPX under the base, and use conductive thread to sew the keys and LEDs to each of their respective pins.
The sensors are the keys with the conductive fabric on them. Using conductive thread, in this diagram presented as wires, we connected these capacitive sensors to pins on the CPX. Also connected to pins on the CPX are our LED lights, in this diagram we only show one but there are four in total, the same amount of keys we have on our piano.
With this code, each of the pins is set to play a tone on the CPX when activated. They will be activated when someone touches the ‘keys’.
When the keys are touched, their corresponding LED is also activated. For example, you’ll see in the block of code on the left, it states that when pin A6 is activated, pin A3 will also be activated.
First I started by using if and else statements. But due to it being a one-time click event, the LEDs wouldn’t change. I tried to counter this by declaring other led pins low while 1 was high, but this only further complicated the situation.
I then went on to implement a button “down” and “up” function. I used “pin” to define the analog pins and within the “down” segment I set a melody and set the pin (A3) to high to turn on the external LED.
In the “up” segment where the capacitive sensors would obtain no pressure so I set the sound to “stop all sounds” and set the pin controlling the external LED to 0. This still was inefficient at activating the LED. Once I changed “pin” to “touch”, the capacitive sensors were outputting through the LED and the Adafruit speaker.
Have the circuit in hand before starting the design. We accidentally made a design that didn’t work with all four LED lights because we didn’t have an idea of what the circuit should look like before we began.
If you decide on using the HeatnBond adhesive, make sure to research which materials you’re using before using an iron. One of the materials we used ended up burning a bit when the iron was applied to it.
- Team: Manuela Ballesteros Pinto, Ronit Sharma, Laila Mariam Imran.
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