Shyam Ravi’s first foray into DIY electronics was when he was only 10 years old, when he began trying to figure out how to hack R/C cars to make them faster. Five years later, his love for electrical circuits has translated into some serious skills: In the video above, Ravi demonstrates how his DIY’ed smartwatch not only boasts a handful of Apple Watch features ($229 for a Series 3), the equipment he used only cost him $20. From his room in Bengaluru, a city in the Indian region of Karnataka, he tells Inverse that his goal was to be able to operate smart home technology with his wrist.
Aside from telling the time, date, and temperature Ravi’s smartwatch can switch on any Internet of Things home appliance, like internet-connected Philips Hue lightbulbs or Amazon’s smart microwave, without the need of a smartphone. That’s a capability that could run you up to hundreds of dollars to enjoy, depending on what smartwatch you’re thinking about picking up. For people interesting in replicating his experiment, Ravi detailed every step of his week-long wearable project on YouTube. Since it was first posted in October of last year, it has since garnered more than 200,000 views, inspiring several members of his audience to dip their toes into wearable design.
“I thought it would be cool to control devices and home appliances from your wrist,” he explains. “While many smartwatches require to be paired with a smartphone to function, I wanted to make a standalone smartwatch that directly connects to WiFi and serves the purpose without the requirement of a [phone].”
Ravi controls his DIY smartwatch using three small buttons and an OLED screen mounted to Printed Circuit Boards (PCBs) that he designed using free software, made by EasyEDA. He got his designs manufactured by Chinese website JLCPCB for the low, and bought the rest of the components on Amazon, which are all listed in an accompanying blog post.
The final step of the hardware process was assembling everything using a soldering iron. Making sure that each and every tiny piece was connected and functioning to power the watch was the most difficult part, he says.
“I had manually routed all the PCB trace connections, which was challenging as I had to accommodate a lot traces in a very small board,” he explained. “It was like solving a puzzle.”
After everything came together, it was time to program the his smartwatch. He used the programming language Arduino to power his creation’s software. The code incorporated the Yahoo Weather API to report the temperature, a bundle of Arduino functions named NTP, and IoT platform Blynk to establish connection to his appliances.
Finally, to keep the watch thin he sandwiched the battery between the two sides of the strap. It seems like a minor detail, but this feat is ultimately what allowed the watch to fit comfortably on his wrist. But after designing a smartwatch from start to finish at the same age many of us were struggling to get high school papers in on time, Ravi isn’t interested in an electronics engineering job.
“There’s very little chance that I might get into hardware design as career, as I am more interested in particle physics and aeronautical engineering,” he said. “But whatever field I get into, I will definitely have DIY electronics as my preferred hobby.”