Set of Eyes - A Wearable & Audible Obstacle Detector

The biggest challenge for blind people and those who are visually impaired is to commute independently; The infamous white cane requires one to leave a hand occupied with it at all times and its range is limited, and service dogs are an optimal solution, but they are not affordable for everyone since they are highly costly, can take up to years to train, and require maintenance and care. I aim to provide an alternative solution that is less costly and doesn't require any maintenance. The solution I am suggesting is a wearable & audible obstacle detector.

As the name suggests, the device is able to detect an obstacle in the path of the user and output the distance to the user through headphones (3.5mm Auxillary). It utilizes a TOF (Time of Flight) LIDAR distance sensor and two microcontrollers (PIC & Arduino) to scan for objects and scale their distance from the user into 0.5m increments ranging from 0.5m to 4m. Furthermore, the audio trigger soundboard used in the system has a hard drive that allows me to store audio files on it and associate them with 11 trigger pins while choosing how the files are triggered on each pin (hold, latch, loop, next, random). The determined distance range of the obstacle dictates which audio file to be triggered. Also, a buzzer will sound an alarm if the distance is 0.5m and will sound a different tone alarm for 1m.

The operation of the device can be described in 3 different phases that are in a continuous loop. These are briefly described below:

• Initialization phase: the user turns on the device using a switch. a welcoming message is triggered prompting the user to enter user manual mode or continue to start detecting. 
• Sensing and Communication phase: there are only 8 outputs to the soundboard (8 distance ranges), there is no need to communicate the actual distance variable from Arduino to PIC. It is sufficient to communicate the range of the variable in increments of 0.5m and each range is represented by a combination of the bits. Therefore, after the Arduino Uno obtains information from the sensor, the distance is quantized into the ranges and then transmitted to PIC using the digital communication method described above.
• Output phase: PIC demodulates the transmitted information and translates it into a distance. Then, the soundboard pin containing the distance range is triggered accordingly.

Furthermore, the device needed to be more user-friendly and it needed to allow for some user customization of the operation. Therefore, the following features were made available:

• Maximum range setup using 4 different combinations of 2 pushbuttons (4m, 3m, 2m, 1m increments of 0.5m),
• Buzzer on/off control using a pushbutton,
• Cycle delay duration setup using a pushbutton (choosing between 0.5 seconds and 1.5 seconds or 1 second when the max range is set to 2m),
• Ensuring the readiness of the user before startup using a limit switch,
• user manual mode containing Audio instructions using a rocker switch and a limit switch to cycle through files, 
• music mode that is similar to the user manual mode in operation, but it contains calming music files to relieve the user from the continuous distance messages, 
• and a rechargeable power bank that powers the circuit and can be used as a phone charger as well,
• An automatic silencing feature when the same distance is repeated 3 times.