pic: IR Lap Counter on the Manchester Kickoff Field

The lap counters mounted under the overpass on the FIRST Overdrive field at the Manchester, NH Kickoff.

How many of the IR sensors are there, 1 per side or is there more?


i mean the whole counting laps thing in relatin to the game not how the sensor works.

There are several (4?) per side.

If I remember correctly, there were 4 sensors

If I read correctly in the manual, FIRST will provide your team with a lap counter for your robot at the beginning of each match.

<R18> ROBOTS must use the LAP INDICATOR provided by the field personnel during all official tournament MATCHES. The LAP INDICATOR is attached to the stopper on the flag pole.

I’m thinking teams may want to pay more attention to the flag pole mount than usual this year. It would be a shame if your flag went flying (and the counter transmitter with it) and your laps don’t get counted!

Pete is certainly right – you don’t want to lose a flag this year!

Also, pay close attention to <R17>. The top of the flag holder must be 51 inches above the floor. The rule doesn’t specify how much your flag holder height can deviate from this value, but it might not take much deviation for the lap counter to miss your robot going by.

Is it smart to rely completely on the lap counter? Of course, I say this without knowing it’s accuracy, and shutter at the murderous boredom a volunteer/ref would have counting laps all day

Here’s the system:


Read for details.


Nice find! At least we know this is a commercially proven system, although it’s designed for a much smaller scale.

According to the website it will accurately track up to 1/4 scale cars on a 24 ft wide track. That more than covers the size and width we are concerned with. One can only hope they have shaken out any bugs before they commit 1500+ teams to it!:smiley:

I’ve used these types of lap counters when I was racing R/C Trucks. The are very durable.
When you get clobbered by another vehicle or go flipping off the track the counters still work.
They are race proven :wink:

not just some random PVC tube zip tied to the bot anymore?