The construction of Project Aegis's initial prototype was a process focused on establishing a larger-sized hardware prototype for proof of concept before miniaturizing it into a full-scale IoT safety system within a wearable ring. The assembly process included trial-and-error, switching various development boards, such as the traditional ESP32, for a more lightweight and flat ESP8266 Wemos D1 Mini. Additionally, we figured out that the "bare-bones" SIM7080G module operated at too low a voltage and replaced it with a standard Waveshare breakout board. We were able to 3D render a precise model of our hardware prototype to get an idea of the potential size of our prototype over the coming months. However, while our potential casing fits the dimensions of our potential miniature ring, we are only capable of making this device to about 3"x4". Materials used include: TPS63020—a buck-boost converter that automatically converts, amplifies, or reduces the current drawn from our 3.7V Lithium Polymer Battery, depending on GPS activity, causing shortages or excesses. We upped the rating of our Lipo battery as we calculated the draw from all of our components combined, from 500mAh to 800mAh. 

We experimented with various wires that would be attached to the linear resonant actuator and settled on the 30 AWG as it fared the best when testing durability while our device was vibrating. These components were then soldered onto a perfboard to make the connections permanent and move from a hobbyist breadboard setup to a more professional design. The tactile push button, due to its color, also meets design requirements in being psychologically appealing to individuals who have been traumatized by incidents of domestic abuse. We have additionally tested the efficacy of our design in meeting our design requirements, namely sending a reliable GPS signal. We have tested in low-signal environments and managed to get within a GPS precision of 1 meter and got a fix on 8 satellites. With this element, we have also made use of our device incredibly user friendly with the integration of our website and confirming that all data inputted into this website is sent to an encrypted database that is then tapped into by the Project Aegis wearable itself. 

 Domestic abuse victims often face significant barriers when seeking help. Even if they have some mobility,  71% of victims' report that abusers monitor their communication, restrict their movements, and/or manipulate them in a manner that prevents them from reaching out in an indiscreet manner. Current safety tools are either too visible, inflexible, or too dependent on established infrastructure or law enforcement, leaving victims without discreet, reliable, and comfortable ways to signal for help. 

The following circuit schematic outlines the integrated hardware architecture of the Project Aegis wearable, designed to balance high-performance emergency signaling with a compact, wearable form factor. At the heart of the system is the ESP32 microcontroller, selected for its dual-core processing capabilities and low-power "deep sleep" modes, which are essential for maintaining the device's longevity. The schematic details the interfacing between the ESP32 and the SIM7080G module, which provides the critical NB-IoT cellular connectivity and GPS tracking required for real-time location reporting. Additionally, the circuit incorporates a DRV2605L haptic driver to facilitate discreet, non-visual user feedback, and a dedicated power management stage—including a LiPo charging circuit and voltage regulation—to ensure stable operation across varying battery levels.

In element H, we will perform latency testing, measuring the time from a user pressing a button to an SMS notification sent to a trusted individual. We will be doing range and accuracy testing, testing the GPS coordinate precision in various environments via our Arduino triangulation testing code in the figure below. We will also be calculating the energy draw of the ESP32 in "Deep Sleep" vs. "Active Alert" mode as well as our SIM7080's signal strength. 

Untestable Requirements Justifications

For safety and legal reasons, high-risk incident effectiveness is modeled through user feedback surveys and expert input rather than live trials. Via Officer Cisneros's input on our project (refer to Element A) and through feedback surveys, we are able to determine that a discreet method for activating our device is a proper design due to how an individual's physiology changes in the fight-or-flight response despite not being able to run a trial run for ethical reasons.

Overall, the building process of Element G was largely a success. However, our circuit design in Fritzing did not accurately reflect what eventually became our hardware prototype as we had to replace the bare-bones SIM7080G module with something more suitable to the 3.7V Lithium Polymer battery voltage. It took several days, too, to figure out how to "warm up" the GPS, and realized later that our wiring was slightly faulty. Our discreet personal safety device would yield real evidence of meeting its requirements as a reliable, independent of existing infrastructure panic button due to its lack of connection to the internet and how it operates via satellite triangulation. If we had to estimate the efficacy of this product, we believe that the device's latency will land somewhere within mere milliseconds. Additionally, if we had to guess further about the device's efficiency and battery life, it would land somewhere within 8-10 hours when used to its full capabilities. We hope in future iterations, too, we are able to cut down on data usage of this device to meet our affordability standards of <100$ as a one-time production cost per manufacturing of this device.