Thursday, February 16, 2012

RC Lap Timer. Go Kart Lap Timer - Part 1

In between other projects I have been working on a personal RC Lap Timer. The system uses a simple mechanism to detect a lapping car and is as a result limited to one car, however there is a secondary goal.

The secondary goal is to design the system to work equally well whether it is timing a passing car or actually in the passing car, in particular I want to be able to strap the lap timer to the steering wheel of an 'arrive and drive' go-kart in order to get in car lap times.

The system uses infra red so is completely portable, it also works equally well whether the transmitter is passing the timer or the timer is itself in a car passing a track side transmitter. The system is not based on a beam breaker and will not register false laps for other cars or karts, instead the system uses a coded infrared signal and could in principle be extended to time more than one car.

Before starting work on the enclosure and user interface the system was tested extensively timing my Tamiya M03.

The Final Form

As the system stands the components are too bulky too fit the form factor I am aiming for -

In the near future when I have finalised the software I will replace the Arduino UNO with a stripboard Arduino which should allow me to fit the entire system in the palm sized project box pictured.

I am currently testing the user interface which allows the user to -

  • View initial screen with session count, recorded lap count and remaining lap count
  • Delete all sessions
  • View summary screen for each session with number or laps, average lap time, best lap time
  • Delete individual session
  • Cycle through individual laps within a session

And also to press record to begin recording a new session. 

I am really looking forward to being able to use this both with the RC Cars and to get back into Kart racing.

Stay tuned ...


  1. Hi! i want to know something: if the car you want to get the time is behind another car, your lap time, can still get the time?


  2. Hi, The lap timer works in two parts, one part is the user interface and lap logging software, the other part is the lap capture mechanism. At the moment I am using Infra Red for lap capture which means that I need line of sight between the car and lap capture module. If there are other cars on the track, this could be as simple putting the IR transmitter part the way up the aerial tube. So yes, can still get the time.

    Duane B

    1. Thanks, for your fast reply.

      i am trying to make a lap timer for car race, but the hardware making get me thinking every day... somebody told me to do it with ZigBee protocol, but everytime the problem about : how can i get the time of every car passing the start/finish line?, even if they are really close?

      So, for your answer i guess you figure it out that.

      Could you explain me more about: "putting the IR transmitter part the way up the aerial tube".

      Thanks (and sorry for my english)