This week, most of my effort went into researching, specifying, and validating our design details. Prior to this week, our design and implementation still had a lot of details up in the air, such as how our wearable device would be implemented and what components we were going to use. I conducted extensive research this week to determine specific parts, communication protocols, and organization of our system down to the component level to get a much better understanding of the specifics of our implementation. I also tried to make sure all the different parts were mutually compatible. Details I researched/validated include:
- Decision to develop both a prototype wearable using off-the-shelf modules and a custom PCB for our final project.
- Choice to use a Raspberry Pico for prototype wearable versus Arduino due to better specifications (buffer storage, RAM) for our use case.
- Choice of Pimoroni MCP73831 to handle power to prototype device
- Choice of 3.7V 400mAh JST-PH LiPo battery to power prototype device.
- Choice of Seeed XIAO RP2040 Plus as compute on PCB final product.
- Choice to use 502025/502030 3.7V LiFePo battery on final product.
- Worked with Haowen to advise about networking component choice regarding compatibility with Pico/FPGA.
For all these design choices, I researched the tradeoffs of the exact components, considered alternatives, made sure they could integrate well with the rest of the components, and found in-stock listings.
With all these design choices further considered, I now feel I have a much better understanding of the direction of our project. That was further solidified by my work on the content of our design review, including with the rough-sketch diagrams that are adapted for our slides. In preparing for the design review, I was led to really think through our complete design and do further research where necessary to confirm the soundness of our design decisions.
My progress on the schedule is not behind per se, but my role for the short term I feel is adapted a bit. Upon further research, the FPGA element may be better left for later while the implementation of the wearable prototype is taking more precedence. I took receipt of the physical FPGA, but the power supply is not in yet, so I can’t do much work in that department. That is why I took on work in researching the wearable prototype design, while Matthew is going to begin development on the wearable PCB.
In the next week, I hope to have all the parts I’m responsible for 100% confirmed and ordered. I am most of the way now, but some final compatibility/organizational checks with the rest of the team are in order before committing to the purchases. Depending on how soon parts arrive, I hope to be able to test a rudimentary communication between the FPGA and the networking module attached to the Pico.