Proxilert: Protection on Your Wrist

In today’s world, personal safety is a growing concern. This project began as a small idea aimed at addressing the increasing issue of sex trafficking in cities across the country, which disproportionately impacts women and children in our communities. Our goal was to design a portable, cost-effective device that alerts individuals when they are near locations associated with known sex traffickers. By increasing awareness of one’s surroundings, the device empowers users to stay alert and take precautions, potentially preventing dangerous situations.

Our design is inspired by everyday wearable technology and utilizes GPS tracking through simple connections, such as an Android phone. Through partnerships with law enforcement agencies and city safety databases, Proxilert can update high-risk zones in real time. This discreet wearable technology can help protect students traveling alone, studying abroad, or navigating new cities, while teaching users to remain aware of their surroundings. As the platform grows, Proxilert aims to create safer communities through proactive prevention, expanding beyond Android.

1. PLA Filament
2. Bread Board
3. 3.7V Lipo Battery
4. Mini Flat Coin Vibration Motor
5. Arduino ESP32C3 Microcontroller
6. Wires
7. Android Device
8. Macrodroid App
9. Fusion 360

We started with our 3D printing aspect - a watch which will contain the GPS and wired parts of our project.

1. Begin by CADding the wristband portion. Create a sketch on the top plane and extrude a rectangular shape, adding protrusions as seen in the image.
2. Fillet on all edges parallel to the green axis line for 2mm.
3. Extrude a 1.8mm diameter circle on both sides of the 2 protruding edges for 1.5mm at a -30 degree angle. Likewise, extrude a 1.8 diameter hole on both sides of male side edges, 1.5mm deep at a -30 degree angle. Copy the body and move so that the male side aligns with the female side of another link.
4. 0.25mm allowance between bodies.
5. Copy and add multiple bodies to complete a watch wristband at the desired length.
6. Designed connectors at the end of each side to clasp the watch closed.

1. Extruded a 45mm diameter circle by 17mm (1mm for lid on top, 1mm for bottom, 15mm inside to hold contents)
2. Offset plane on both sides to extrude rectangles to hold male/female parts
3. Male part: extruded rectangle, added the same 1.8mm diameter, 1.5mm deep hole with a -30 degree angle on both sides; 2mm fillet on top and bottom edges to maintain consistent style
4. Female part: extruded 2 rectangles on opposite sides and added two protrusions going outwards by the same dimensions as the holes; 2mm fillet on top and bottom as well
5. Used a variety of chamfers and fillets to get a sleek look, then New Sketch > Offset inwards by 1.5mm, then extruded to cut downwards into body to create a chamber for components
6. Lid: 1mm width; added 2 protrusions on one end and one longer on the other side
7. Compared lid to main body and extruded to cut in corresponding areas with ~0.1mm allowance for protrusions in lid to fit

Time to print! Export Fusion drawing as an STL and import it to Prusa 2.9.2. Slice and export G-code. We used midnight black generic PLA and no supports, with a printing time of 27 minutes on an MK4. Our model was designed as a print-in-place, so no additional assembly was required after printing.

On the Seeed Studio XIAO ESP32C3:

1. Soldered all the ports and added pins, as well as WiFi antennae
2. Vibration motor: input (yellow wire) to D3 port; output (orange wire) to GND port
3. Battery: (+)(-) soldered directly onto battery port, but added male + female connectors to plug and unplug when not in use

On Arduino IDE:

1. Completed setup (first three pictures) as instructed on: https://wiki.seeedstudio.com/XIAO_ESP32C3_Getting_Started/
2. Uploaded code so that while connected to the ESP32 wifi, we are able to control the vibration motor powering on and off by going on http://192.168.4.1/vibrate
3. Tested and working.

On LG K10 (must be Android phone) MacroDroid app:

1. Created a geofenced entry named "Test Location 2" with a 100m radius around the coordinate
2. Boundary added as a Trigger for the task; will trigger action when geofenced location is entered; has a 30-second location update rate to ensure speedy notifications
3. Created the corresponding Action to open website, set website to http://192.168.4.1/vibrate.
4. Added an additional Display Notification as an Action for more notifications to users in case watch does not vibrate; also allows for testing the prototype to see where issues lie
5. When testing: make sure phone is connected to ESP32C3 WiFi, all hardware components are connected, and MacroDroid task is switched on.
6. Our product is tested and working. Visit https://youtu.be/DoY55PdS0Yk for a demo.

With all 3D components printed, we inserted our electronic hardware into the main watch body and put on the snugly-fitting lid. Our product is done!