Milestone 3

Implementation

A Fanny pack shall be used in the front of the belt to store the Arduino, breadboard, and battery. There shall be a 3-D printed encasing to house this technology and keep them immobile during user movements. Wires shall run through a hole in the fanny pack and the belt all around. We have a buckle to secure the belt around the waist. Four Ultrasonic sensors and their respective motors will be spaced equidistant around the user (front, back, left, right).

Testing

Initial Tests for the Belt included a cardboard platform that was constructed to test the viability of TOFSense-P and TOFSense-M for our belt design. 

Through various tests with the TOFSense-M, a discovery was made that the sensor was inaccurate after a distance of 2 meters and sporadically recorded incorrect data in closer ranges. The group then pivoted to try the Ultrasonic sensor. This new sensor was accurate up to 3.7 meters and a lot of code was already provided online (a lot less tweaking required). The only major downside from testing is the sensor has a low frequency which makes it harder to detect objects entering perpendicularly to the center.

The group decided to make a makeshift belt constructed from rubber bands in order to test the sensor in conditions closer to the final product. For this design there would only be one sensor (in front) and one motor (held by user). When the vibration reached highest level the user shall know there is an object in front of them and take the proper maneuvers to avoid.

The two most important parts of our code during testing, was our error checking and power scaling. In the coding snippet on the left, we limit false data inputs by checking if the past two data points had a huge gap (improperly reading max distance). In that case we retain the last data point and continue collecting data.

In the right coding snippet, you can see that from different distances we change the power setting (the left number in the parenthesis of the analogWrite(). This is a way to give feedback to the user of the general range of the object in relation to their position.

Teamwork