Looking for new projects to do with SquareWear 2.0? Here is an idea: combine SquareWear 2.0 with touch sensing to make a digital piano! It works as a standalone project and no additional hardware is required. Take a look at the video first.
How does this work? First, SquareWear 2.0 has a built-in buzzer, so it can already make sound. Next, touch sensing is detected in software. It basically exploits the principle of capacitive sensing: every time you touch an Arduino pin, it slightly alters the capacitance of the pin. This change of capacitance can be detected using a variety of methods. The simplest is to set the pin to digital input mode, and turn on the internal pull-up resistor. This will start charging the capacitor. By detecting the time it takes to charge the capacitor, you can infer the capacitance, and in turn tell if a finger touch has occurred on the pin. That’s it! Because SquareWear maps out available pins to large pin pads, this makes it particularly well-suited for touch sensing.
So I wrote a quick demo as a proof-of-concept. First, I found a function that implements the capacitive sensing from the Arduino playground website. It basically returns a touching sensing value, which can then be compared to a threshold. You may need to adjust the threshold to increase or decrease the sensitivity. The demo scans through all 12 pins available on the SquareWear 2.0 and plays a tone for 125 milliseconds if a pin touch is detected. As a result, the buzzer makes a chiptune type of sound. The code also uses the on-board pushbutton to switch between three octaves: C3, C4, and C5. The LED will blink when a tone is played.
Every Wednesday is Wearable Wednesday here at Adafruit! We’re bringing you the blinkiest, most fashionable, innovative, and useful wearables from around the web and in our own original projects featuring our wearable Arduino-compatible platform, FLORA. Be sure to post up your wearables projects in the forums or send us a link and you might be featured here on Wearable Wednesday!