Personal Lap Timer Features

[DuaneB]

Hi,

I am building a low cost personal lap timer for my own use however if there is enough interest I would look into outsourcing a short production run.

I have a prototype working at the moment and plan to complete the following features and will consider any additional features suggested here -

1) LCD Display of total laps, best lap and average lap

2) Stop/Start timing laps

3) Review recorded lap times

4) Clear recorded lap times for new session - maybe with the option to keep the summary data - total laps, best and average

Because I don't want to look at the timer while I am driving -

5) Buzzer to confirm lap captured

6) Double buzz if lap was faster than average

7) Triple buzz for new best lap

Anything else that might be useful ?

Duane B.

rcarduino.blogspot.com

[DuaneB]

Want one ?

Close up -

Duane B

[TomEG]

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[DuaneB]

What price tag are we talking here?

Tom

Probably free if you want to build one yourself, other than that the most cost effective option would be for me to produce them as self assembly kits to keep the shipping and labour costs down. In the short term I will keep working on the features and then when I have the software testing complete I will look at the cost of -

1) A pre-programmed chip with schematics and parts list to buy/build the rest - basically just shopping and soldering required to complete.

2) A delux version of the above with a ready made PCB with component placements preprinted and all components supplied for assembly - no shopping, lots of soldering

3) A pre assembled ready to use version.

Given my resources I will most likely only manage one of the above, I quite like the concept of number 2, but which if any option would you be more interested in ?

Duane B

[TomEG]

deleted

[DuaneB]

Hi,

Totally buildable with a little soldering experience. Apart from testing the code, the other big task for me to complete is to downsize and replace the main board.

The main board on my blog is an Arduino UNO, its great for prototyping, but too expensive to use in a final design which will either include a standalone version or the components to build one.

Duane.

rcarduino.blogspot.com

[speedy_w_beans]

Is there a transponder in the car and some sensor for the ground, or is this just a box that you have to manually press buttons to capture lap times? How does someone use the box at the same time they're driving? Some transmitters already include lap timer features in them, so unless there's a transponder in the car and a pickup loop, this looks like it could be difficult to use while driving.

EDIT: I don't want to be totally negative on this. I'd be more interested if your box would connect to a wire loop under the finish line and you engineered really inexpensive transponders (<$10) to go with it. Otherwise I would just stick with the timing features built into transmitters due to ergonomics.

-Paul

[DuaneB]

Is there a transponder in the car and some sensor for the ground, or is this just a box that you have to manually press buttons to capture lap times? How does someone use the box at the same time they're driving? Some transmitters already include lap timer features in them, so unless there's a transponder in the car and a pickup loop, this looks like it could be difficult to use while driving.

-Paul

Hi,

Yes there is a transmitter in the car, there is also a receiver which I will keep detached - this is so that I can mount the main unit on the steering wheel of a racing kart from time to time. There are still some components from an earlier prototype which I need to move into this version - a few high visibility indicator LEDs (recording, signal/lap detected) and the most important feature - a buzzer.

I really liked the buzzer in testing, I get one beep to confirm the lap and two beeps if its a new session best all hands free and without taking my eyes of the car.

Duane B

rcarduino.bogspot.com

[stu22]

Is there a transponder in the car and some sensor for the ground, or is this just a box that you have to manually press buttons to capture lap times? How does someone use the box at the same time they're driving? Some transmitters already include lap timer features in them, so unless there's a transponder in the car and a pickup loop, this looks like it could be difficult to use while driving.

EDIT: I don't want to be totally negative on this. I'd be more interested if your box would connect to a wire loop under the finish line and you engineered really inexpensive transponders (<$10) to go with it. Otherwise I would just stick with the timing features built into transmitters due to ergonomics.

-Paul

I'd also like to see what the solution for the transponder/pickup would be. Everything so far seems to be about programming the opensource Arduino.

The topic of building a lap timer and getting away form the virtual monopoly owned by AMB comes up all the time. The problem always seems to come down to not having a cheap and accurate way to measure the laps themselves. As far as I know, there is no cheap/opensource transponder setup that would work.

[TomEG]

deleted

[stu22]

The blog says it uses a coded infrared signal, so I suppose it must have line-of-sight between the transponder and receiver.

I caught that, just wondering about the specifics of what he is planning on using. I looked into building a system myself a while ago and found the problem of actually counting laps was the big one, writing the software and building a display is the easy part. I'm not saying it can't be done, I just want to see what someone else has come up with.

IR can work but you'll need a sensor bridge like with the I-Lap system. Making the field of view for a single sensor wide enough to pick up the transponder causes interesting geometry problems with getting the thing to pick up at the same spot every time, and narrowing it will cause problems in getting it to reliably pick up the transponder at all (unless you run multiple sensors on a bridge to effectively build a larger but still narrow sensor zone.)

[chevyman3]

That's interesting i'm in if the price is right and i'm pretty handy with a soldering iron. How big is the transponder or receiver that goes in the car?

[speedy_w_beans]

I caught that, just wondering about the specifics of what he is planning on using. I looked into building a system myself a while ago and found the problem of actually counting laps was the big one, writing the software and building a display is the easy part. I'm not saying it can't be done, I just want to see what someone else has come up with.

IR can work but you'll need a sensor bridge like with the I-Lap system. Making the field of view for a single sensor wide enough to pick up the transponder causes interesting geometry problems with getting the thing to pick up at the same spot every time, and narrowing it will cause problems in getting it to reliably pick up the transponder at all (unless you run multiple sensors on a bridge to effectively build a larger but still narrow sensor zone.)

You also have the problem of the IR receiver saturating in sunlight (ala outdoor) conditions even with a filter, and even if it is on a bridge pointing straight down. The emitter has to compete with the sunlight, too, so any coded signal has to be low duty cycle and high pulse current to have a chance of being detected. I suspect this is why AMB uses radio signals instead of anything optical -- it simply works under the broadest number of conditions.

-Paul

[DuaneB]

Hi,

'writing the software and building a display is the easy part' - Everything is easy when someone else is doing it

In fairness, Arduino is a success because it is easy to get up and running with, if you have a poke around my blog you will see that since receiving my Arduino over christmas, I have used it to -

Log data from my M03

Here - http://rcarduino.blogspot.com/2011/12/data...ata-logged.html

Create a remotely switchable child mode

Here - http://rcarduino.blogspot.com/2011/12/data...ata-logged.html

And have the beginnings of an in progress traction control system -

Here - http://rcarduino.blogspot.com/2011/12/trac...monitoring.html

As for the IR system, we currently use an IR system for our races in Dubai, as you can imagine we have no shortage of sunshine to test the system (not mine, a commercial one) and it is not a problem, I have also tested by own hardware before embarking on the user interface part.

I am surprised that more people do not use micro controllers in their cars, it would be trivial to build an MFU for a scale truck for example at a tenth of the cost of commercial units. Then again, maybe its just not that easy when its you that has to do the work

Anyway, give it some thought the possibilities of combining RC and Micro controllers are pretty exciting.

Duane B

rcarduino.blogspot.com

[stu22]

When I asked about how you intend on detecting a completed lap I'm just curious about what you have in mind for a solution. It's an interesting engineering problem that I spent some time looking into and would like to see what someone else has in mind. If you're going with IR do you plan on having a full sensor bridge, a single sensor, dual sensors, or something I never though of?

A while ago I saw this, http://www.redrc.net/2009/09/grenit-perfor...-30/#more-22223 , and it got me thinking about what I could build myself. My plan was to write software and run it on an old netbook. The program is really a pretty straight forward process of recording the time the sensor trips and doing some grade school math.

Where I ran into problems was finding a cheap way to detect the laps. IR would work, I don't think the sun would really be a factor. The stereo's in my Miata and Corvette both have IR remotes which work perfectly fine from 20 feet with the tops down and the sun shining directly on the things. You also have the wonderfully simple solution of not pointing the sensor at the sun if it were a problem, there is an elegance to the simple solutions that's tough to beat

However, I would have had to build a sensor bridge to get the accuracy I wanted, and at that point it would have been easier and cheaper to just get an I-Laps setup. I also looked into RFID tags but a high speed sensor antenna would have again put the cost of the thing into the range of the I-Laps system which is already built and known to work pretty well. Then I went back to IR and though of using a pair of sensors and attempting to figure out a way to use the overlap in their coverage as the trigger. After that I got side tracked into 3D printing

BTW, the Arduino is what controls most of the current generation home 3d printers these days, including my Thing-o-Matic. I've spent some time poking around the thing and have to admit I never really considered it in a RC toy applicaiton. I also spent some time poking around the rcarduino site you linked to and have to ask if the projects are going to be opensource?

[bakaguyjean]

The blog says it uses a coded infrared signal, so I suppose it must have line-of-sight between the transponder and receiver.

The KO System uses the same type of infrared signals,it really only works well indoors. Outdoors it has so many problems missing laps. Hopefully somebody can come up with a system that works and does not cost an arm and a leg.

[DuaneB]

The moment of truth !

So far the lap timing system is working very well, I have tested it successfully in bright daylight, but due to work and family, not extensively before the sun sets.

Tomorrow I will take my current setup to work and test it at lunch time in the full power of the Dubai sun.

Wish me luck, its all been too easy so far.

Duane B

rcarduino.blogspot.com

[DuaneB]

Hi,

If you remember, this thread is about a lap timing system that fits in your pocket, you can take it to the BMX Track, or the parking lot and run hot laps against your mates.

Its one car only, hence the hot laps, but with no laptop, sensor bridge or faffing about its a great solution which you can build yourself for about 20 dollars.

It works perfectly well outside, even in the Dubai sunshine.

Here is part one of the build along, anyone with a soldering iron should have no trouble in transferring this to strip board.

http://rcarduino.blo...g-part-one.html

Part two is an overview of the transponder with a parts list, part three will cover adding the IR Detector and tranponder so you end up with the complete solution as showing in some of the other videos.

Duane B

[atf300]

cool cool cool,

would you be interested in selling pre made ones ?

[DuaneB]

Hi,

I designed and built the device because RC Cars are only so much fun without having something to measure you skill or setup against, as for selling pre made ones, I would love to but living in Dubai shipping them is a massive pain.

The electronics is pretty simple and the software is available on my blog so you could have a go at building one. You can literally cut and paste the software and upload it to the Arduino through a USB Cable using any Windows or Mac computer.

I have a lot of other Arduino RC Projects, here is a one I built recently to add active yaw control to a tail happy m04 -

http://rcarduino.blogspot.com/2012/07/rcarduino-yaw-control-part-2.html

Duane

[atf300]

Hi,

I designed and built the device because RC Cars are only so much fun without having something to measure you skill or setup against, as for selling pre made ones, I would love to but living in Dubai shipping them is a massive pain.

The electronics is pretty simple and the software is available on my blog so you could have a go at building one. You can literally cut and paste the software and upload it to the Arduino through a USB Cable using any Windows or Mac computer.

I have a lot of other Arduino RC Projects, here is a one I built recently to add active yaw control to a tail happy m04 -

http://rcarduino.blo...rol-part-2.html

Duane

ill take a crack at it then

[DuaneB]

Hi,

Post on the blog if you need help, I hope to get some video of the 'build a long' version at the track this weekend, it will be the final step of the build - adding the IR Detector - its the simplest part of the build so nice to finish on something easy.

Duane

[shenlonco]

does this do only one car per box or can it do laps for more than one car?

[Butler]

Could you configure this so the buzzer goes off after a set amount of laps?

Can you run more than one in close proximity?

I am thinking if a few were racing, and you had one each, you just race until the first buzzer goes off.

[shenlonco]

After looking on his site i think it only counts laps for one car and i don't think you can use more than one box for each car because each car will trigger all tyhe boxes to register laps because they are exactly the same units