Slot car Lapcounter/timer

Good morning wise folks,
Looking for ideas for a Slot car lap timer.
I have a great set up using an old PC,but we are going portable and moving all that stuff is a pain.

What would be cool is a stand alone for 3 lanes that could count laps,display lap time and remember fastest lap time.

Oh and it needs to cost less than $20 per lane.

Have some ideas?

sort by: active | newest | oldest
frandecai5 years ago
Take a look to my little lap and time counter for two lanes ho slot track project. It has a little video with the 'thing' working:

I used limit switches to detect the cars and the arduino microcontroller to do all the job (count laps, time, and save the fastest time of each lane). The whole project would cost about 25$ (including switches, LCD 16x2 display, buttons, resistors, etc).
What sensors are already in place for the PC system?

How does the information need to be displayed? All at the same time, or one piece at a time, with buttons to scroll through?

The best option would be to use a basic microcontroller, which you should be able to get, with a programmer for less than $60. For a display, a 4-digit, 7-segment display would be the simplest option, but to display more data, an LCD would be better.

If you need a sensor to detect the cars passsing the timer, you could place some LDR's in the track, possibly with a light overhead, or use hall effect sensors to detect when the magnets on the car pass over it.
2FER SLOTS (author)  The Skinnerz6 years ago
Thanks for the comment Skinnerz,

Currently using IR detectors imbedded in the track.
Hoping to display info without pushing buttons while racing so crucial info at the same time.....
leader/position current lap current lap time fastest time

Since posting this question I have been diligently searching and am coming to the same solution as you have mentioned. I know very little about microcontrollers, but willing and able to learn.

Do you have a circuit and code in mind?
Thank you for helping.
I'm assuming that each car has some sort of IR LED mounted on it somewhere?
Do you know if the LED is permanantly on, or if it emits a frequency unique to each car?

As Goodhart says, a simple counter for each track would be the simplest option, and should be able to count up to just over 1K laps, with only a 4digit display, and a BCD to 7-segment decoder (and the usual resistors)

If you need to constantly display information for each car, a 4 line LCD with the standard hitachi driver would work, and has pleanty of documentation, tutorials, and examples.

Before you get a microcontroller, decide what other hardware you want, such as the displays, sensors and any other I/O you want, like a keypad to enter a time limit or No of laps.
If you didn't want to go the "whole uC route", and like to build things electronic, you could opt for building the counter from scratch with a 4017 decade counter and/or you could use a 4029 CMOS counter (or any number of counters out there) for this purpose.