My final project will be a timer for use with yoga and meditation. This idea springs from a specific problem in my life: I do yin yoga in the evenings before bed, and I like using a timer to tell me how long to hold each pose, so that I can relax and not have to count time in my head. However, the only timer I have is on my phone, and looking at my phone screen shortly before bed can make it harder to sleep. Even if I fall asleep alright, the experience of looking at my screen every few minutes feels subtly disruptive to my meditative state of mind.

In this context, the goal is to make a timer that is as unobtrusive as possible. More specifically, it should blend smoothly into a yoga- or meditation-focused space and mindset, both in its aesthetics and in its interaction design. Hence, I am focusing on ambient light as the primary medium of communication. The device will be a small dome of translucent plastic, from which light in a warm color will emanate. The material will be chosen to diffuse light in order to achieve a soft ambient light field. While the timer is counting down, it will give off ambient light. When time finishes, the light will briefly brighten, then turn off.

To make the interaction subtle and unobtrusive, the device will have no screen or physical buttons. A touch-sensitive area on the top of the dome will register taps from the user. Each tap adds one minute to the timer. If the timer is not timing, it will begin timing when tapped. Hence, one sets the timer to n minutes by tapping n times, and if one wants to add more time in the middle, one can tap again. Subtle details will be important here - for instance, the light could flash briefly with each tap, giving the user visual feedback that their tap was registered.

The dome shape shows a smooth, organic surface from top and side angles, but also allows more artificial-looking details to be hidden underneath. Specifically, on the flat bottom of the dome would be an on-off switch, access to change the battery, and potentially other controls for customization. Four small bumps or legs on the bottom of the dome would raise it 1/8 - 1/4 inch off the surface it sits on.

There are many additional features which I could add, if I have time. For instance, it might be interesting for the ambient light to "breathe," dimming and brightening at the pace of a relaxed human breath. However, I might not want my breathing pace regulated by the machine at all times, so I'd want a switch on the bottom to toggle this feature. I could add a dial, or a pair of buttons, to set the breathing pace. I could add switches or dials for other customizations, such as the brightness or color of the ambient light. For more precision with the timer, a switch could toggle between one minute per tap, and thirty seconds per tap. If it could be added without disrupting the quality of the ambient light, a row of LEDs somewhere on the dome could display how many minutes are remaining.

However, the minimal version of the product would simply have an on-off switch, the tap interaction, and the ambient light while timing. If other buttons or switches are added, the on-off switch should be larger, so that it can be quickly found by feel.


  • Dome of translucent white material - I need to figure out details on this. 3-D printed? Something vacuum-moldable?
  • Internal structure to hold Arduino, battery, LEDs, tap sensor, neopixels. The dome should be able to be disconnected from this internal structure, so one can access the Arduino's USB port for reprogramming.
  • Legs and bottom face.
  • Neopixels strip(s) for ambient light.
  • Arduino Uno.
  • 9V battery and connector.
  • Force-sensitive resistor to detect taps.
  • On-off switch.
  • Possibly, additional switches and buttons, or potentiometers to act as dials (e.g. of brightness).


  • Fabrication of the dome and internal structure is especially challenging. It should be sturdy and look aesthetically finished, since this is meant to be a standalone and portable device. However, it must also allow quick disassembly via screws to change the battery or to access the Arduino.
  • Choosing a good material and thickness to diffuse light in the way I want.
  • Driving the Neopixels - the Arduino can only power so many at once. If I can't generate enough light when powering the neopixels off of the Arduino, I'll need a second battery.

Brainstorming / Sketches