As a team, our focus this week was on refining the overarching architecture for PosturePal alongside our respective individual tasks. A shift in our system strategy involved narrowing down our central control unit. While we initially weighed using a Raspberry Pi or an STM32 board, our research demonstrated that a compact, energy-efficient SoC featuring built-in BLE (like the nRF52840) is far better tailored to the wearable’s compute and wireless transmission demands. Beyond the controller, we pinpointed several core trade-offs that require physical validation prior to finalization. These include selecting between I²C and SPI protocols, establishing sensor timestamping methods, and determining if localized multi-point haptics offer sufficient utility to warrant the extra power draw, cabling complexity, and signal noise on the IMUs. Building a preliminary test bench will let us analyze these parameters in a unified setup before ordering our custom boards.
Splitting up hardware, firmware, sensing, mechanical housing, haptics, and app development lets us make concurrent progress, but it leaves our deliverables tightly coupled. Ensuring the full system functions properly means that these distinct parts must interface seamlessly. To mitigate this risk, we plan to prototype interfaces early on and integrate as early as possible. Looking ahead to next week, we plan to first finalize the design review/proposal, and if orders come in, then we would also look to wire the three IMUs onto a physical test rig, gather sample data across various user postures, assess bus communication and experiment with haptic placement to gauge its influence on sensor readings.