Jack Cruden's portfolio & blog


21st September, 2016  ·  2 minute read


LIMELIGHT is a wearable technology project that promotes and encourages fitness. It’s a wristband that allows runners to keep an eye on their performance during their run. LIMELIGHT aims to promote physical activity in a fun and interesting. Primarily aimed at people who are less active but still have a competitive side LIMELIGHT can be used with your running group, with a bunch of strangers or on your own.

Initial Concept

Using an Arduino with an attached accelerometer LIMELIGHT records your running data and transmits it publicly to anyone within range via a radio transceiver. Other LIMELIGHTS in the area will receive your data and compare it with their own running data. The LEDs will then change colour to reflect your progress relative to nearby LIMELIGHTS. If you’ve made less progress than the majority of people nearby your wristband will turn red, if you’re ahead of the competition your band will fade towards green!

Revised Concept

I had a lot of trouble getting the FM tranceiver working reliably and I revised my initial idea to be more of a solo-fitness tracker. It would no longer broadcast your run statistics.



This project was inspired by the competition I have with a friend when we run together. We often use smartphone apps to quantify and compare running performance. The only annoyance with this is that it’s in hindsight. Aside from buying expensive smartwatches there wasn’t really a way we could compare performance during the run.


I know various running apps for smartphones allow users to share their runs live for people to view online. An obvious issue with this approach is that it’s difficult for running companions to view these broadcast runs while they themselves are exercising.

Point of Difference

LIMELIGHT has a very simple and clear indicator, requires absolutely no configuration and has no buttons.

Challenges & Issues

This project has plenty of potential challenges and issues, hardware and software.

  • Delays in shipping
  • Faulty components
  • Issues with assembly
  • Code faults
  • Issues relating to wireless transmission


This is the minimum set of components needed to assemble one LIMELIGHT.

  • Arduino Mini
  • Accelerometer
  • Colour LEDs
  • Battery

Want to see more like this? I only post updates once every few weeks.