“We wanted to create a solution,” she tells us, “that would be cheap to build, easy to run, and provide meaningful data. In the bigger picture, it feels really important that we’re able to build continuous datasets so we can get a more thorough picture of what’s happening at our coasts.”

It was also important for the team to try to understand the mechanisms driving coastal change. “Understanding how and why coasts are changing is the first step in robustly evidencing policy decisions to protect them,” says Steph.

Buoy oh buoy!

After six months of planning and designing, including “two jam-packed weeks” in which the team physically built and deployed their prototype (see magpi.cc/smartbuoy for videos), Smart Buoy finally landed in Grenada’s warm waters.

But, as Steph explains, there were some issues along the way. “The most challenging and time-consuming part was designing the Buoy casing and ensuring it was waterproof. While making the system solar-powered was pretty straightforward, ensuring it used minimal power required building a power scheduling system. We also set the bar pretty high in terms of what we wanted the Buoy to measure. Ensuring all the components worked to a good degree of accuracy was a massive challenge, and something we didn’t quite achieve.”

In addition, the team had problems with the memory of the Arduino used inside the Buoy, while SPI connections required a multiplexer. “During some initial tests, the sensors gave very odd results, so we had to go back to basics. On the plus side, the Raspberry Pi [used in the base station] worked flawlessly!” says Steph.

The Smart Buoy is essentially a solar-powered system of sensors which is controlled by an Arduino. “Once deployed, the Buoy sends measurements of environment characteristics (including wave height, wave power, and water temperature) via radio to a Raspberry Pi base station, which hosts a real-time dashboard and stores the measurements in a database.”

The team chose Raspberry Pi as it’s straightforward to program and connect to a radio module so it can communicate with the Arduino inside the Buoy. “Running Linux meant it was simple to run a database and a server for the dashboard. The maximum distance for the radio signal is 1 km, so we had the base station on dry land while the Buoy was out at sea,” explains Steph.

Hopes for the future

Although the team weren’t able to keep the Smart Buoy in Grenada’s waters for as long as they’d hoped, many positives came out of the exercise, including the lessons they learnt from the build. “We’d love to be able to invest more time in finessing the project and making more Buoys – a network around the island would be amazing, and would give you a really interesting, holistic (and hopefully meaningful) look at the coast.”

In addition, they introduced their prototype to some officials from the National Science and Technology Council in Grenada: “Their feedback was that something like the Buoy, which gives reliable data with little manual input, would be invaluable.” But, most importantly, Steph and the team have achieved their initial goal of making their Smart Buoy on a budget. “When we embarked on this project, it was to make a prototype to show that you could make something akin to a thousand-pound research buoy without splashing out.”

While they know that Smart Buoy is still in prototype stage, the team hope to make improvements. “It would be amazing to see the Buoy in production, and we believe it would be a really valuable tool for education, citizen scientists, and even small governments.”

Reaction from others has been positive too, as Steph reveals: “It made us so happy when a teacher in Spain got in touch to share that they were remaking the Buoy with their class… We really hope this project has inspired others, and would love to hear from anyone who could help us take the Buoy to the next level!”