What started out as a request to clean up a mess of third-party wiring on some human-powered vehicles ended up being a multi-year development of a fully custom electronics package that involves various sensors, custom-designed PCBs, custom power management, and so much more.
We ended up with a modular package of sensors feeding to microcontrollers that stream to web-based software, allowing real-time monitoring of the vehicles location, crash detection, the ability to analyse performance data, post-race review and playback, and endless classroom opportunities outside of the race to learn from the data.
The Before-Times
When we first started working on the Energy Breakthrough series one of the initial pain-points from the team was the mess of electronics in the vehicle. All vehicles require a headlight, tail light, a horn, and a speedometer, and all the teams to date had solved this by using a mix of bicycle components. Bicycle headlight taped to the nose, a bicycle tail light taped to the back, a cheap bicycle computer strapped to the cockpit inside, and a bicycle horn with the trigger wire zip tied to the handle bars. Each one has its own batteries, and all those batteries (on multiple vehicles) needed charging by the coach before each race, and overnight in the hotel for the following race days. If a single battery was forgotten or a component failed then the vehicle is disqualified from the race.
We knew we could do better, and our initial proposal was to centralise the power to a single battery on each vehicle and use "dummy batteries" in the devices that allow external wired power to be fed in. We quickly realised that dummy-batteries are unreliable and just all-round terrible, so started playing with other solutions. Around the same time, we had started playing with adapting off-the-shelf power tool batteries into projects and realised this would be absolutely perfect in this situation. They're cheap, available locally, shock/water resistent, and easy to work with.
First Attempts
Our first prototypes used a 3D printed battery holder and a custom PCB based on an Espressif ESP32 microprocessor. We had the PCB manufactered for us then assembled it at the Hackerspace. It took in sensor feeds from the wheel, chain, and steering, and saved the data to an SD card on the PCB.
The HUD displayed sensor data on the screen for the kids to see, in the hope that it would gamify things and let them see their speed and compare it with each other.
The prototypes did extremely well, and were a hit with the kids and the team. They were definitely prototypey and we had some inevitable issues such as 3D printed battery brackets cracking from the surprisingly huge amounts of vibration/impact the vehicles go through, and some other minor problems. The vehicles did finish the race, and we confirmed from the team that it was a massive improvement over previous years, but we had lots of things we could do better for next year.
Current Version
The current version as of 2026 race season is V2 of the HPVECU board and has lifted everything to a new level. Sensors have been developed further and reduced in size significantly while being integrated much better into the vehicle. We've gone to a dual-battery system using a custom power management system (meaning the vehicle now has 2 custom PCBs) that lets you hot-swap batteries, run a single or dual batteries, and uses injection molded ABS brackets so that they're much stronger.
We're now streaming data in real-time via a 4G modem inside the vehicle, storing the data on a server we set up with custom software, and then streaming the data to the pits via a custom-developed series of applications that let the pits (and the team in general) see where the vehicles are at all times and monitor important information. There is now a GPS module on each vehicle, and an IMU giving us data such as whether the vehicle has tipped over (crashed) which instantly alerts the pits and tells them exactly where it happened.
The horn button is wired through the middle of the handlebar, meaning there are no more wires dangling around the riders, and also means they have much easier access via a thumb-switch to use the horn vs taking their fingers off the brakes to trigger the old button.
The horn and headlight are now independently powered and the horn can be triggered by the rider with their button, or via the ECU if required to get attention after a crash.
All of the sensors are reaching their final-form of being extremely compact and hidden away in the vehicle chassis, becoming a proper part of the vehicle itself and generally just more solid and reliable by being designed to fit better.
Future Goals
V3 of the HPVECU is already in the works, with the main goals of making it more "production ready" for other teams if they wish to use it, or even for other types of vehicles. It is now running dual ESP32 microprocessors to handle all of the sensor inputs while streaming the data better up to our servers, and sensors will work over a CANBUS system allowing as many or as few sensors as the team requires.
Reminder that this page is a living document and gets updated. It was last updated on 5 November 2026.
