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Free lapcounting system.

Posted: Thu 23. Jan 2020 18:35
by kiklo
As some may have read I use Racecoordinator for laptiming and have been testing and sorting out problems over a long period.
Status pr. 2020 is there are no better system for MagRacing and it got all the function you need and even more.
Cost ? Very little if you have a PC to use. I use a 5 year studentpc and it is all good.

I urge you to download from racecoordinator.net and install and have some demo run.
When you are ready to install I will help you out if you get stuck.

You can have a look at how I have done it in the pic. It consists of : Tracksensors connected to a arduino on a breadboard with a few components.
Total cost far less then U$ 20.

3 of 4 sensor groups (one in pit lane)
IMG_20200123_190626.jpg
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Black : 4 groups of resistors and transistor, blue in coming from track sensors, yellow convectors to Arduino pins. I use Arduino Nano V3. Blue cable is usb-cable to pc.
IMG_20200123_190645.jpg
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I can provide you with a ready programmed Nano if you supply me with a unit and pay for postage if you are not familiar with that stuff.

Re: Free lapcounting system.

Posted: Thu 23. Jan 2020 18:50
by MagRacer
Wow, looks good :-)
I finally got more space for a track, so when I have the base build, I will be interested. :-)

Re: Free lapcounting system. Schematics

Posted: Fri 24. Jan 2020 07:26
by kiklo
I think the original pic of the layout on the breadboard has been corrupted so I have posted this again. (All credit goes to Skalm.)

Re: Free lapcounting system. Schematics Explained

Posted: Fri 24. Jan 2020 07:36
by kiklo
Again cut and paste from the original post : http://magracingforum.com/viewtopic.php?f=16&t=265

One important note about the diagram: I've used normal transistor symbols for the IR phototransistors since the program I used to draw it with didn't have the proper symbols. In reality the IR phototransistors only have two connectors ("legs") so the dangling wire in the diagram is not there. I hope that doesn't cause too much confusion.

Please also note that while I have three IR phototransistors in the diagram it is, as mentioned above, possible to attach as many as you'd like.

My sensor setup currently still only lives on a bread board, but I will make a more permanent solution Soon(tm) and post pictures of that as well.

And what about the Arduino code?
Well, it should be attached in a zip file, but I really don't want to go into details about it as I've rambled on for far too long already :)

I have added comment to the source code so it should be fairly readable, and it's also incredibly simple once you get down to it, so it should be usable as-is: upload it to an Arduino, attach the sensors (and +5V and GND) and see what happens :)

Re: Free lapcounting system. PCB in its way, sort of.

Posted: Wed 5. Feb 2020 18:35
by kiklo
I finally took the time to design a PCB for the laptimer sensors. It will probably take a month before I have them due to circumstances i China.

BUT I decided to rethink, moving away from my present setup.

All components are now where the sensors are. Only wirering going to the Arduino.

One sensor-row for one lane is one unit and you just add a second sensor-row to be place adjacent to the 1st to take care of lane 2,3,...x.
Also making it easy to piggyback 5V+Gnd so you only have to run one par of power + signal for every lane to the A.

Being ca 8x3 cm wide with room for 16 sensors for each lane should even be usable for 1:24 scale track.

This will make it easier to use any Arduino and not having to fit it to a board.

Having the PCB designed it is even possible to order some with you as shipping address if you care to have.

You will only need 2x10K resistor, one 27K resistor and one BC547 and 5-16 IR-LED receivers 940nm for each lane.

Pictures will come.

Re: Free lapcounting system.

Posted: Wed 5. Feb 2020 18:43
by kiklo
Board-pic

Re: Free lapcounting system.

Posted: Mon 9. Mar 2020 09:57
by kiklo
Ok, Sensors PCB have arrived. Found a few point to enhance: bigger solderpads, some extra holes for clamping cables etc.
But this is how it is for now:
IR-race-sensor1.jpg
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IR-race-sensor2.jpg
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Re: Free lapcounting system.

Posted: Fri 24. Apr 2020 15:58
by kiklo
Before I mount them inlane I'm going to test if overhead sensor is an option. I made as small mount for one lane and will post the result.

Maybe putting the ir led in a helmet or any other suitable place.

Still waiting to get the in-car PCB's from China.
IMG_20200424_174554.jpg
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IMG_20200424_174625.jpg
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Re: Free lapcounting system.

Posted: Mon 4. May 2020 07:57
by kiklo
Initial tests shows with 3 mm IR emitter a distance up to 40 mm is usable. With the original cars 10 mm works, not that running the original cars upside down is possible.

Makes me think this timing system could be used for other RC cars as well. Like Mini-Z etc.