My First Hardware Startup: Rimo (2)

[ This series of articles is about my startup company, Rimo, from the conception of the idea, recruiting a team, producing prototypes, to fundraising. ]

The image below shows the first-generation 3D printed Rimo prototype. The protruding “T”-shaped area at the bottom houses light sensors. These sensors continuously scan the screen of a smartphone, searching for control signals. Once a control signal is detected, Rimo rotates the smartphone either left or right. At the time, I didn’t have the funds to purchase a 3D printer, so I had to find alternative channels and borrow one from the school. Fortunately, the school had abundant resources, and the 3D printer wasn’t in high demand.

3D-printed prototype Rimo exploded view

The video recoreded in 2016 below demonstrates how I remotely control Rimo using a computer in a video call. Unlike other products, Rimo doesn’t rely on Bluetooth connectivity. Instead, the Rimo phone holder establishes a connection using visible light emitted from the smartphone. This means that the phone doesn’t need additional apps or Bluetooth pairing—it’s plug-and-play. However, there is a drawback: a portion of the screen is sacrificed at the bottom because that area is used for linking with Rimo.

Rimo Demo

When I first conceived the idea of Rimo, I felt very excited. It was the first idea I had after years of studying, sparking thoughts of entrepreneurship. Some people often claim that university education is useless, citing examples of successful entrepreneurs who dropped out of college (such as Bill Gates, Steve Jobs, and Mark Zuckerberg). They argue that university is a waste of time and that students should focus on generating ideas and starting their own businesses as soon as possible. However, my experience with Rimo has led me to believe that this perspective only fits with a very small set of very smart people.

Creative ideas don’t materialize out of thin air, and creativity doesn’t spontaneously appear. They require a solid foundation of knowledge and deep understanding of technology.

Creative ideas don’t materialize out of thin air, and creativity doesn’t spontaneously appear. They require a solid foundation of knowledge and deep understanding of technology. Before Bill Gates even attended Harvard, he had already helped the school rewrite its course scheduling system. Mark Zuckerberg, a programming prodigy, created several popular websites during his time at Harvard, some of which even overwhelmed the school’s network. If they hadn’t known how to code, how could they have envisioned the potential of software and successfully founded Microsoft and Facebook? These geniuses didn’t succeed merely because they dropped out; rather, they were ahead of the curve, already proficient in programming and brimming with creative ideas that they feel urge to put into practice. Unlike them, most of us start learning coding in college. If we dropped out at that point, we’d lack the essential software background necessary for building a startup. Creativity and business ideas aren’t free—they require a broad knowledge base, a willingness to learn, and constant interaction with others. Rimo’s concept emerged through years of teaching optical components and discussions with many students each semester. Without knowledge of optoelectronics, I wouldn’t have known that light sensors could easily receive signals from smartphone screens, converting light signals into electronic ones. Without programming skills, I wouldn’t have realized that I could manipulate video frames to transmit control signals. And without those brainstorming sessions with students, I wouldn’t have generated the idea behind Rimo. Each ingredient was indispensable.

To prove the feasibility of Rimo’s concept, I spent a considerable amount of time writing software. My goal was to inject control signals into the FaceTime video stream. Think of it as a kind of video effect—like blurring the background or adjusting the lighting. However, in my case, I wanted a different kind of “effect”: I want to insert control signals (such as black and white pixels) into the video stream, positioned at the bottom of the video. These pixels would be controllable via keyboard input, making it more challenging than typical visual effects.

Over several months, I simultaneously worked on writing my thesis and completing the software. I assembled an optical circuit using a breadboard (a circuit board commonly used for prototyping). The circuit connected to a motor that I hadn’t yet attached to anything—it was purely for demonstration purposes. The circuit board was quite large, approximately the size of an A4 sheet of paper. My plan was to shrink it down to one-tenth of its size as seen in the picture above. Once I confirmed that everything worked, I excitedly invited my friends to see my demonstration. Here’s how it went: I initiated a video call from my computer to my phone. After connecting, I placed the phone on the circuit board. Then, holding my computer, I ran to the adjacent room. The magic happened—I could control the motor next to the phone from the neighboring room. With a triumphant stride, I returned to the original room, basking in everyone’s praise.

Working principal of Rimo. The blue signal represents the video stream, while the red signal represents the control input

My labmates finally realized what I had been working on for those months. Some of my friends weren’t surprised; they assumed I had installed additional software on my phone, allowing Bluetooth control of the motor. To dispel this notion, I called a friend’s phone and asked them to place it on the circuit board. As expected, I could still control the motor from my computer. That’s when my friends truly marveled, and I humbly accepted their second round of praise.

Buoyed by their encouragement, I performed the demonstration for my professor. Despite his expertise, he couldn’t fathom how it worked. It felt like a victory—finally outsmarting the professor!