You know why health officials tell you to wash your hands and avoid touching your face? Every day, you touch things without realizing it; doorknobs, handlebars, and light switches. By touching these items, you are picking up whatever may be contaminating them, and also leaving behind whatever may be on your hand.

Preventing surface transmission is as simple as reducing the touching aspect of our everyday lives, and due to the exponential growth patterns displayed by quickly spreading illnesses like COVID-19, eliminating surface transmission of viruses can play a huge role in reducing the total number of cases, and rate of spreading.

What it does

Wavelength is a hardware attachment that you can slap onto a light switch, which will allow anyone to use the light switch without touching it. You just need to hover your hand in front of it, and Wavelength will flip the switch for you, no touching required. In the process, Wavelength saves you from potentially picking up and leaving pathogens on the light switch.

How I built it

Wavelength is a simple piece of hardware created with an Arduino Uno. It's connected to an ultrasonic sensor that notices an object when it's closer than 10cm. In that case, it will communicate with a servo motor, telling it to flick the light switch behind it.

I then put the contraption inside of a cardboard casing. I could have made it smaller for the demo because there's extra space inside for batteries. Putting it in a decent casing probably took as long as creating the hardware component itself.

Challenges I ran into

The largest challenge I ran into was the fact that my batteries were unable to provide enough current for the servo motor to flick the light switch with the necessary force. I realized this after a couple of hours trying different battery combinations, but I didn't have anything on hand that would work. So I decided to temporarily have my computer supplying the power just for the presentation.

While trying to get the motor to flick the switch properly, I also had to engineer a paperclip onto the end so that the motor would have more leverage on the light switch by pushing the switch farther from the center.

Even getting the thing to stick on the wall properly with the least amount of duct tape was challenging. Wavelength needed to be attached to the wall very solidly so that the motor wouldn't push the whole machine off of the wall while pushing the light switch.

Accomplishments that I'm proud of

This is my first hardware hack, and I'm proud of the fact that I got two nights of proper sleep. I found working with the Arduino to be quite intuitive, and I feel like I've learned a lot of hardware and manufacturing skills that will come in handy for future hackathons. I've been thinking about this idea for a while and I'm glad I managed to create it for a hackathon, turning it into reality very rapidly.

What I learned

I learned a lot about applying my knowledge of physics and circuits, even though this was such a simple hardware hack. It's almost as if I could've calculated everything before I created it. For example, I probably should have done so when I was installing the batteries, because I didn't realize that I needed more current for a couple of hours.

As usual, I learned to debug applications. But this time, it was very different because it's not just a software thing to consider any more. It was fun to explore the connection between software and the real world through a hardware hack.

What's next for Wavelength: Make any light switch hands-free

Wavelength is currently an attachment for light switches, but with the power of simple hardware, any commonly touched area can be made hands-free with a similar implementation. Again, think about how much we touch things like doorknobs and sink handles, when we can easily eliminate the touching process from them.

I was also thinking about adding the ability to control Wavelength through a mobile app by connecting both an Arduino and mobile phone to one server, so that users can control the lights in their local area network. It's kind of like controlling things with Google Home, but more affordable!

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