As  a class project, two students decided to build a bike computer that could measure distance, speed, cadence and power output. With a bunch of normal off the shelf sensors, an LCD screen, and the knowledge of how it all works, they assembled a device that can do all that for $60. But before you run off to Radio Shack, know that it may not have the same simple user interface as your Garmin, and has a bit of a DIY appearance.

Why did they do it? Simply to show it could be done for a whole lot less than commercially available products as a class project.

Click past the jump to see Mark and Brian explain their device, and hit 500+ watts on a rusty chain…


  1. Run it through R&D, make it presentable and reliable and it will soon be a $1000 item to the consumer. But if you like to tinker that is very cool! I wouldn’t mind just having the power measurement to simplify things.

  2. $60 power meter on a $25 bike haha. Check out that wheel wobble! Impressive setup though. Insane that they can get all that info without spending the industry standard $1500 on equipment.

  3. I love to see kids tinkering with hardware in creative ways instead of writing apps. These little project circuit boards are a great way to learn. Take a look at the Zwift blog to see a cool post about how one of the founders started tinkering in a similar way, modding one of those garmin ant+ sensors.

  4. It’s a good start. Needs more strain gauges and better filtering. They didn’t say if it was calibrated or temperature reliable.

  5. I think they were just trying to see what it took to get a basic prototype working. Obviously you won’t really use that, but at their young age it’s cool to dive in and make the parts. It’s those little early steps and successes that can lead to greatness.

  6. Robert W: We did our best with software calibration but temperature variances made that harder and werent accounted for. This could be made better easily though.

    jon: I was fairly certain the resistance was on when we filmed

  7. My Elite turbo trainer rarely ever gets the cadence correct, this is better.

    Good work from a these electrical engineers…shame they didn’t minor in mechanical engineering too, they would have spent an extra dollar for some chain oil.

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