lap counter

i intend to make a lap counter using ir as the triggering mechanism. but i also like to have several different ir transmitters all running at the same time up to 8 but probably only 2 or 3 will only ever be used and the same time. id like to run with several check points 4 to be exact. im thinking of running nanos in the 4 checkpoints and something a little meatier like a due to handle time keeping & lap counting plus any thing else i might want to add down the line. i want to using bt to link all to relay checkpoint trigers, 5 devices will be together tide but im kinda worried about range. it will be set up in a room about the size of a gym with direct line of sight it will be used to count rc car laps and times. so 2 or more cars many trigger the at once sencer and id like it to know that there were multipul car detected and witch ones i know i can u a 555time to get different pulse out of the to of the ir so it know the difference in cars but when 2 cars r detected at once i get the hiccup as how to do this. with this sad what is truely feasible and what is a pipe dream. or a better way to set up shop or to design said project. thanks. im also wearied that this things wount be able to about trigger the sencer as they will only be in view for 1/2 sec at most.

sorry about my spelling and grammer i know its bad any ad vice would be help full, thanks


Killerrock: sorry about my spelling and grammer i know its bad

It does not take long to check spelling ---

Anyway, a more serious issue is that your description of what you want to do is not clear. Can you draw a diagram of the track and the locations of the sensors and post a photo of the drawing?

Why are you counting laps at more than one location on the circuit? How many cars will be operating at the same time? How many measurements will you need per second? How will you know which car triggered a sensor?

I would be surprised if you need more than a single Uno or Mega to do the whole job. Using a single Arduino will make the programming much easier.


And keeping track of more than 1 car can prove difficult. How do you separate the lap times if cars overtake each other? 1 car won't be hard, 2 would be impossible keeping track of individual lap times with just a handful of IR sensors...

Have a look at my stopwatch class - - it supports lap time and you can create an array of them.

spell check and gram only work so well can tell u that the wrong word. like there they're and their. that why i apologized first. and dislexea makes i way worse. so i cant tell its garbage. lol thanks for understanding. any ways back to the project

the programing aspect of it would not be to hard as i do have 2 years of vb in my belt and yes its a different language but it should make things ezr or at-less not as overwhelming.

there will be any were between 1 to 8 cars. 555 times ceasing each ir to blink and different hz to identify each car. like 555timer1 would blink (.--) 555timer2 would blink (..-) 555timer3 would blink (-.-) or something like that. i have not worked it all out

one of the issues id might have is when 2 or more cars pass under the ir sencer at the same time. under speed it the would recognize that 2 car r there and properly id them. or should i threw out the ir and go a different rough. then out put it in a text file type format.

id be happy going down to get 1/10 of a sec as most of this would be either me practicing or just a couple friends having fun. id love to get to 1/1000 but that's probably to over kill not counting lap at different locations but check points and then relay them back to the master Arduino. the resion im like to im looking at multi arduinos is for running check point to sc if doing this to get passed this obstacle was faster or slower. and running wire to get it to 1 arduino would not be fesable unless there would bee another way to run wireless sencers. but the project will run in steps sorry i dont have a layout of the track as it will be changing

Working backwards...

You don't need to post the exact layout - just a diagram that gives us a clear idea of what you have in mind for placing and using the sensors.

I don't understand how the sensor will be able to detect the pattern from the 555 timer and use it for timing purposes. If you have a 555 constantly pulsing ..-..-..-..-..- what is stop the sensor/Arduino from reading that as .-. or -.. for example. If you study how serial data is formulated you will see that there needs to be start and stop bits - but how could you guarantee that the start bit only starts when the car gets to the sensor?

You may be able to design a code pattern that can be deciphered even if only part of it is detected - but I think it would have to be much longer than 3 bits and it would have to be repetitive. You could probably distinguish ...-...-...-...- from ..---..---..---..--- provided there was time to detect several repetitions.

Also, how do you ensure that the transmitted IR signal is ( a ) only detected when the car is at the end-of-lap line and ( b ) is visible for long enough for the code to be correctly interpreted.


Hi, I think the OP has each car with a flashing LED, hence the LM555, and each car has a unique flashing frequency which is its ID. You can mask off the sensor to make a gate area to detect the car.

The OP points out that he will have a problem with 2 cars in range of the sensor at the same time.

Tom.... :)