Friday, May 11, 2012

Lap Timer Preview

Video 1 - Lap Review Mode

A quick tour through part of the menu system. Session summaries with best and average lap times, select a session to review the laps within the session.

Its very simple interface, ok to enter a mode, cancel to exit a mode and up/down to cycle through any options in a mode.

Video 2 - Daylight Laps

One of the challenges with using infra red for lap timing is that daylight will easily saturate the detectors rending them useless. My solution to this is to enclose the detector in a shade however even this isn't enough. To get reliable lap detection with no false laps I have painted the inside of the detector enclosure with 'ultra flat' paint.

The particular paint I have used is manufactured by Krylon and is targeted at hunters, paintballers and airsoft players that want maximum camouflage with no reflection from their equipment. The ability of this paint to suppress reflection stops any daylight from getting to the back of the enclosure. The only light that can reach the detector at the back of the enclosure is light directed directly at it, the light from a lapping car.

Test Car

Tamiya M03 Mini fitted with a Tamiya Sport Tuned motor and good for around 40Km/h.

The lap timer should be good for full size race car speeds, I plan to test at 120Km/h in the next day or two using my daily driver and a long stretch of empty road.

For race car and Kart speeds I will see who I can persuade to test the system at the Dubai Autodrome.

Inside The Lap Timer

Keeping the cost down.

A standalone Arduino, an LCD screen and not too much else.

Small enough to fit to the steering wheel of a Kart.

More soon...

Duane B


  1. Hi! Im really interesting in this proyect! I'm 1/10 Electric driver, and i can make a lap timer with arduino. When you have a kit or a list of item, i buy construct!


  2. Hi,
    I have been thinking about the best way to publish this and whether I should base the published design on an Arduino UNO or a standalone Arduino. I will set myself a deadline for a decision and start publishing shortly.

    Duane B

  3. Good news, if you want you can contact me, my job is sysadmin and think that i can help you (and me of course) .My hobby is drive rc 1/10 touring car (Xray t3 2011) modified (LRP x12 4.5T) and Stock (European Touring Series kit Speed passion).

    Thanks. to contact me javivu arroba gmail punto com

  4. what number of NPN transister to drive buzzer ?

    my lap timer 90% finished from you.

    very thanks.

  5. Hi, its good that you noticed the transistor and buzzer, I need to update the last step in the build along series to include them. In the later versions I have a menu option to switch between the buzzer or an external PC Speaker driven through an LM386 Amplifier. The transistor is just a 2n2222, I will update the final post with a full schematic over the next week or so. If you want to try the LM386, the circuit is here -

    If you contact me through the Arduino Forum I will send you a zip of the latest version.

    Duane B

  6. I'm feeling it for completeness only need a SD card reader. Prediction will you have to incorporate in your code and design this option?Thank's Marconi.