Design Review Report (Interim)

Ethan:

This week I focused on the design document. My team and I met after the presentation, and discussed the feedback we got as wall as what changes in direction we wanted to make to our design documents. We realized that our presentation wasn’t good because while it did an excellent job of explaining each individual part, it made little mention of the overarching goals of the project as a whole. A large part of this week was spent figuring out how to reorganize and present our project in a meaningful way. I wrote the draft for the mesh portion of the design document, which will be finalized tomorrow.

Michaela:

This week I worked on material for the design document. Mainly this has been taking the information from our presentation, along with the notes we received afterwards, to provide a complete overview of the design of our project from high to low-level. One of the major things we worked on together is discussing how to best layout the design holistically, rather than individual pieces. This included creating an explicit chart of relative areas/aspects of the headphones, features, metrics, and verification we wanted to hit for the project as a whole, rather than individual pieces. This way, we can explicitly state why we are doing and including certain things in our overall design. Another thing I worked to do is to create a list of buzzwords we used during the presentation, so that we could be sure to properly define them in when discussing them in the design document.

Finally, I worked on writing the actual design document.

Winston:

I focused on the design review presentation last Sunday; since then, I started to work with my teammates on the corresponding report, trying to re-organize the information at hand per the feedback with regard to our presentation. In particular, I was in charge of drafting the outline of the report according to the consensus from our discussion, since both Ethan and Michaela are quite preoccupied by the production of Lunar Gala.

In terms of hardware design, I started the layout of the schematics and the corresponding enclosure design. I found out that one side of the headphones is about 60mm thick (including cushion, audio driver, acoustic foam, electronics, and thickness of enclosure). The dimension is shown diagrammatically as follows:

Therefore, as a team, we decided to move the inductive charging receiver coil (which is reduced in size in the diagram above for clarity – it is actually 36mm in diameter). Specifically, it would be moved to the center of the headband. As a result, I cannot maintain the symmetry between the two sides of the headphones and thus have to put different components into each side.

We will further discuss how to reorganize our schedule to accommodate this unexpected change in hardware design.

Team:

We decided to organize the design report by features and high-level needs and wants, instead of by hardware, firmware, software, or algorithm areas. In particular, the breakdown is as follows:

High-Level Requirement	Features	Competing Metrics
Good Sound Quality	Low-noise circuitry	Circuit complexity Component area Performance Power consumption
	Active noise cancellation	Algorithm run time Performance Circuit complexity
	Passive noise isolation	Volume Performance
Audio Sharing	Effectiveness and robustness	Latency Recovery from non-root failure Effective link speed
	Ease to set up	User test
Usability	Long battery life	Playback time Multi-playback time Standby time
	Intuitive UI (gesture control)	User test
	Fast USB charging	Thermal performance Component area Performance
	Wireless charging	Coil area Performance
Basic Functionality	Bluetooth audio	Performance Power consumption
	Physical enclosure	Size Comfort

One prominent risk is the major revamp needed in hardware design due to the relocation of charger coil and thus the basic design principle of symmetry between the two sides of our headphones. We will resolve this by tomorrow.

Design Review Presentation