Project: Tapo

Tapo is a tangible device encouraging people to create beats and perform percussion music with daily cups. What kind of beats it can produce? The volume of the liquid in the cup, the material of the cup and how people interact with the cup matter. The pitch and the timbre depend on the resonant property and the material of the cup. People’s gesture decides the speed or the pattern of the beat.

In the past one and a half week I accomplished every items listed for my first milestone.

1. System Design: I sketched the whole system design and labeled every component in the sketch.

2. Basic Diagram: Based on the system design, I finished the system diagram.

3. Quick Prototype: I have finished two prototypes so far. One is composed of a Trinket, a 1K resistor, a step-up regulator, a transistor (TIP 120), an accelerometer, a solenoid and a battery. The other one is different from this one by using a Teensy and a smaller transistor (FU3910) instead. These two prototypes are currently supported by a big battery set and USB power supply. In the final version I will replace by two separate batteries supporting the micro controller and the solenoid, also use all the tiny components in one enclosure. The Trinket version almost has the final look of this project except for the transistor and the batteries. However, the cheap board Trinket does support the Serial debug. Therefore, I built the second prototype by Teensy for the next phase: gesture’s detection with accelerometer.

Prototype 1

Prototype 2

The prototype 1 is implemented to test the solenoid and the prototype 2 combines solenoid and accelerometer, which converts the data of accelerometer into the speed of the solenoid. Both prototypes are testified that solenoid, accelerometer and the entire hardware configuration can work.

4. Circuit Design: In order to produce multiple devices, I customised a PCB board for all the hardware components, including batteries ports, solenoid interface, transistor, resistor, step-up regulator, and accelerometer.

5. Component Purchase: I did a research on every component I would use in this project and test several transistors and boards, listed a budget for the hardware that I need. I have all the parts at hand for just one prototype. Here is some links of my wanted components:

Trinket: www.adafruit.com/products/1500

Batteries: www.amazon.com/gp/product/B006N2CQSS/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

www.adafruit.com/products/1570

Solenoid: https://www.sparkfun.com/products/11015