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Bat Eyes 1.0, an Arduino device that can help blind people navigate their way, designed to replace the traditional cane.

Why this?
My maternal grandfather was a surgeon of ophthalmology, and dedicated his entire life to helping the visually impaired. Seeing the blind struggle in many situations in my day to day life, I decided to use my interest in robotics to help the blind, and continue my grandfather’s work in a way.

Since I wanted even people without phones or internet connection to use this, I made it independent of other technology like phones.

I wrapped it around the arm because I felt that using their arm to navigate was something blind people could do best. Many of them spent a lot of time using canes, and asking them to just drop their hand and suddenly use, say, their head, would be too much of a challenge. I also made sure to allow them to have both hands free.

I used a buzzer and potentiometer because it was the easiest. I tried different things with vibration motors, but none of them worked well enough. The full volume of the buzzer was too difficult to continuously hear, so I added the potentiometer to adjust volume.

The Logic
This device uses an ultrasonic sensor, a sensor that sends out ultrasonic sound, and waits for an echo. Depending on how long the echo takes to reach it, it determines how far away the obstacle is. Since this works in different levels of brightness, and has a range of about 4m (13ft), I decided that this sensor would be the most useful for my prototype.

Once I have distance, I could just calculate pitch. I decided to relate them with simple linear algebra, y = mx + c.

Each tone is played out for 0.5s. This way, the Bat Eyes check for obstacles frequently, and the tone is more or less consistent.

Plans for the next model
While this is cool and all, this model does have some drawbacks. First off, I haven’t encased it in any 3D Printed casing. Everything is out in the open, and held together by Lego. This will definitely improve in the next model, making it real world applicable.

An ultrasonic sensor is also not always useful. It does not detect angled surfaces (the sound bounces off without reaching the receiver). It also cannot detect soft surfaces, and hence, people. Of course, if they get about half a meter away, it detects it, but anything beyond that, things get tricky. My plan is to use a camera in Bat Eyes 2.0, and use AI to detect the obstacles. That way, it would have more applications. Wish me luck!”

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