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The word bicycle has gained a new meaning in these times of environmental worries. Millions and millions of people already use this vehicle in a daily basis, and every year the number of supporters of this practice grows.

ChronosBike wants to take the cycling experience to new level!

ChronosBike is a system which uses the unique capabilities of the eZ430-Chronos to achieve a low power, eco-friendly and high-value measurement system for bicycles. It can be used to keep track of your training's results, record the general environmental properties of the route, to take a look in the altitude difference of your travel or even to simply turn on the lights of your bicycle.


Ricardo (left), Patrick (right)



  • All the energy for the microcontroller and for the lights comes from some magnets and two induction generators. The movement of magnets attached to the wheel changes the magnetic flux passing through a loop of conductive wire causing an electromotive force, and as consequence an small electric current. This current is filtered and is stored in two capacitors.
  • One of the great advantages of this system is that the induction generator almost doesn't offer resistance to the movement. You can ride free and have light at the same time!
  • Eighteen magnets were used because the system also controls the light. It is important to say that just one magnet would be enough to supply the eZ430-Chronos using the LCD and the RF.
  • The RF network was made using SimpliciTI (peer-to-peer), the connection and synchronization from the watch and embedded system were made to minimize power consumption.

Chronos Bike Unit

  • This is an example of how the eZ430-Chronos can be used as an development kit. The watch is used as an embedded system which collects data from the bike and sends it wirelessly to the watch.
  • The speed sensor is a simple reed switch, that switches as the magnets get closer to it.
  • The circuit detects the light level of the ambient and switches the Bike's LEDs automatically.
  • Instead of using normal incandescent lamps, ChronosBike features an ultra low power light system using LEDs. In total 4 LEDs provide the right amount of light necessary for night trips and safe rides. The idea is to use a small duty cycle and blink the LEDs quickly; this reduces drastically the power consumption for the lights and give sufficient luminosity.

Chronos Watch Unit

  • One new menu was added to the data logging mode. It has the special synchronization feature that enables a low power RF communication, using SimpliciTI.
  • The Watch acts as the user interface with the Bike Unit. All the trip data are stored in the FLASH memory of the Watch so that you can later upload this information to your PC.
  • In this project, the communication Chronos-Chronos and Chronos - Access Point was implemented to work together. Feel free to use this project as an example for further application involving the eZ430-Chronos and the SimpliciTI protocol stack!

ChronosBike Control Center

  • One GUI was developed in order to analyze the data from the bike. It provides information about the travel, such as max speed, altitude, temperature and distance. Besides that, it can generate several kinds of graphics.

Pictures & Videos

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Making of

Usage Instructions

After installed Chronos Bike can be already used. Follow the steps to use the Chronos Bike.

  • Select the Menu LIS (listening) in your Chronos Watch.
  • Ride your bike as much as you want.
  • In the end, press "DOWN" to close the session.
  • When you get home, connect your Chronos Adapter and open the Chornos Bike Control Center.
  • Push the Sync button in the Chronos Watch.
  • Push the Download button in the ChronosBike Control Center.
  • You can already see your reports about your ride on the TCL.

Source Code and Hardware Schematics

The project was entirely developed using the free version control system All the source files including the hardware schematics and PC scripts are stored in a public repository.

Download the Source Code

Build your own ChronosBike

What you will need

Preparing the Bike

Building the Hardware

Installing the Software

Alternative build for ChronosBike

The ChronosBike PCB was designed to be independent of the Speed Sensor and Power Input types. You can easily change the build to adapt to your needs. For example, a infrared light sensor can be used for speed measuring instead of the magnetic reed switch, and a solar cell or a battery can be used as power input. Use your imagination and make ChronosBike even more fun.