Rowing Computer

This is my attempt at building a custom rowing computer to help during training and races.

The goal of this project is to give the cox useful, real-time data so they can make better calls while rowing. I’m aiming to get a working version ready in time for a race on the 21st of March.

Overview

The computer is designed to display key rowing metrics:

• Split (pace)
• Distance
• Stroke rate
• Averages of all of the above

All of this will be calculated using just two sensors:

• An IMU (for motion and stroke detection)
• A GPS (for positioning and speed)

To improve accuracy, I’m planning to use sensor fusion, combining IMU and GPS data to get more reliable speed readings. The IMU will also be used to calculate stroke rate.

The data will be shown on a screen for the cox, and also transmitted over WiFi to a coach’s phone for live feedback during training.

Web Interface

This is the online web portal that allows coaches to access the data:

WhatsApp.Video.2026-03-25.at.17.31.26.mp4

Here’s an example of what the display looks like:

You can also view a timelapse of the project here: https://lapse.hackclub.com/timelapse/Rufa2XrtfnKe

Electronics

To build the computer, the plan is to use:

• 8x M3 screws
• A perfboard for the circuit (to keep costs down)
• A fair amount of hot glue for sealing

Hot glue is being used mainly to waterproof the electronics, which is pretty important for something going in a boat.

Here’s the schematic:

Even though this schematic is shown here, the actual build will likely be done on perfboard rather than a custom PCB.

Enclosure Design

Below are some exploded views of the enclosure:

And here’s the case without any components inside:

Notes

• Sensor fusion (IMU + GPS) is the main challenge and will likely need tuning.
• Waterproofing is a key focus, especially for real-world use on the water.

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If you’re interested in building something similar or improving on this idea, feel free to use the designs and experiment with it.