# Ultimate Personal Lap Timer



## hankster

If you could have the ultimate personal lap timer, what features would you want it to include? Lap Times of course. MPH readout? Save and compare laps from different runs? Graph and print out lap times? Other ideas?

What price would you be willing to pay for the Ultimate Personal Lap Timer?

Note: This would NOT be a scoring and timing system (ala AMB) but a personal timing system such as the Orion unit.


----------



## Dan the Man

Crap, I gotta get back to work on FreeLap...


----------



## HOOPD1

There are only two things I would change from the ORION unit,the ability to count more laps than 60 and it should include a tripod of some sort.Other than that its close to a ultimate deal already.
I fully beleive that eventually one of the radio manufactures will incorporate a lap counter in the radio,Futabe already has one in the radio but its hard to hit that button every lap at the same time.
I guess the ultimate lap counter would be one that counts laps for me whenevr my radio is on.


----------



## Northerner

a print feature would be awesome, built in flex leg tripod that folds up, doesnt have to be as small as Orions unit, download feature would be sweet, audio capabilities, if it could read an amb personal transponder.

oh and if it could go ahead and drive my car better then me, then it would be priceless!


----------



## marig

While I don't think this might be what you had in mind, I would love to have instantaneous car velocity recorded every 1/10th of a second or so, to see if the different pinion I just put in the car is really helping, or if that chassis setup change I made really is getting me through the turns faster. The most I would (like to) pay for something like this would be $250.


----------



## Nutter

Dan: Yes, you do  I'm looking at alternatives to the Linx RX/TX's for mine now (need something smaller and cheaper), and I'm moving away from the idea of magnetics. I'm still not set on how it's going to work, but after discussing it with some electronics engineers, it really did sound like it'll be a lot easier (and will actually work) doing it all with RF, much like AMB does.

Hankster: Sorry for being off-topic. I don't think I'd be very interested in another personal system as the Orion one does fit the requirements "ok". If you're looking for something to sell, feel free to sell Dan's FreeLap, or mine (I'm still not even decided on a name.. heh), when they're done.


-Nutter


----------



## hankster

I'm not looking to compete with AMB because I don't think it can be done.... I've researched it. But I think that there can be improvements in a personal lap timing system. Besides, this is just a personal project that others could build if they want. Just trying to get some ideas on what some would like to see on a personal timing system.


----------



## RCRacer6.1

Hank, heres mine. A small unit I can stick to my radio that would collect the data and have a small screen to show lap times. It would also beep as I completed each lap. After I am done practicing I could take this unit and connect it to some kind of PDA and send the data to it. I would like a program to do exactly what nascar does when they are qualifing. I want it to show me where my car is good and where I am slow at. I also want to compare between my other friends data they have collected to. Sounds like a lot but it is probably possible to do now.

Craig


----------



## tfrahm

I own an Orion LCS, so like others, I'll use that as my starting point... (some of my "wishes" have already been mentioned, but I'll recap them here for completeness...)

* Either a built in tripod or a way to attach it to the transmitter would be great -- transmitter mount might be cool, as it would make it easier to hear YOUR LCS when more than one is in use or the envrionment is noisy... (edit) -- Tranmitter mount might also solve a problem with "missed laps". when the receiver is mounted low (even with a tripod, etc.), it is possible for another vehicle to block the IR signal and cause a missed lap. A side issue would be the "range" of the IR signal, as some driver's stands are pretty far away from the track (vertically, etc.)...

* Smaller receiver (necessary only if transmitter attached).

* Battery monitor in receiver unit (I've had the unit "die" when a battery went dead in the middle of a run).

* More memory in reciever unit (more than 60 laps for sure for Oval racers) -- maybe store a DAYS practice sessions for later download at home (don't have to drag a laptop to the track for downloading/saving EVERY individual run one at a time).

* USB port for universal link to PC...? (I hate one of a kind cables that only the vendor can sell you...)

* Easier changing of "transponder" ID for the receiver -- right now you have to scroll through 999 numbers on the LCS to change numbers...

That's it for now...


----------



## SecretSquirrel

This is something I have thought about quite a bit.

Things I would like to see is:

1. The ability to record more than one car at a time
2. The ability to record sector times (via repeaters or something)
3. Some onboard DAQ functions (measure motor temp, current draw)
4. Be able to transfer laptimes to Palm or Laptop via cable or IR
5. Be able to turn off that annoying beeping 
6. The stuff others have mentioned - tripod, battery level indicator, keep several practice sessions, etc.

I dont have a good sense of what I would pay, but R/C people are notorious for speeding LOTS of $$$$ if they think it will help

Maybe we can get your Ultimate Lap Counter to work with Dan's new timing system.

SS


----------



## swtour

*Tri-Pod mount for LCS*

I took a piece of 1/4" thick plastic about 1" x 1" drilled and tapped a 1/4 x 20 hole in the center of it and shoe goo'd it to the bottom of my LCS box. Wal*Mart sells a really cool "Mini Tri-pod" for about $5.00. Thread this into the block and you are all set to go .


----------



## Ennjay

It would be nice if it could tell you sections where you were slower. This way you can see what parts of the track and what obsticles you are having a problem with.


----------



## JeffPatch29

Interval times, so you could know what chassis changes did to the car in the corner, Line tracking, so you could see variance in your line on the track to help with the consistancy, tripod, battery indicator, more memory, lap top capability, DAQ features like battery temp, current draw, motor temp, maybe some sort of measure of wheel spin? some of these things are asking a lot I know, but you did say ultimate. I'd be willing to pay upwards of 500 bucks, after all motor dynos cost over 500, you chassis is more important than anything, so why should a chassis dyno be around or over 500.


----------



## hankster

Thanks for the feedback as it is useful. First and foremost, I want this to be a personal lap timer and affordable. Because of that there will be no DAQ functions, no multiple car counting and no telemetry. Any or all of these would make it too expensive for the purpose it is being designed for (personal lap timing).

With the idea that some think are important, mainly sector timing, I’ve rethought things a little. Plans are at this time to put the actual lap-timing unit in the car with the IR emitter trackside. This solves a number of problems. One is that an unlimited number of cars can run at one time and no one has to worry about "channel numbers". 

Second is you could place a number of IR transmitters around the track to get your sector timing.

Third is that the IR transmitters will be small, smaller then the size of a 4 cell pack. They will also be inexpensive and the batteries should last for many many hours. This also allows for easy mounting on a tripod using just servo tape or Velcro.

My guess at this time is you'll be able to record about 500 "events". An event would be one timed section. If you have one IR transmitter (for full lap times) that would mean 500 laps. If you have 3 IR transmitters, that would mean 166 laps... etc.

While a "special" cable would be used to download the data into a laptop, instructions would be given on how to make the cable and they'll be pretty simple to make. There may also be an LCD option so you can look at lap times without a PC.

Not sure if I want to add a "buzzer" to it yet, might make it an option.

I have no plans on selling built units. All the info to make it will be freely available so if someone wanted to, they could download the PC board template, the programming and component list for free and buy/build everything themselves. They can also buy the PC board and components from me and build it. Hopefully the convenience of buying everything in one place makes it worth it to buy from me, but it will not be forced on anyone.

My guess is you should be able to buy everything for well under $100 and most likely under $75.

Once this is done and working properly, I have other projects in the planning stages!!!!


----------



## lordraptor1

*personal lap counter*

how about dyno tuning the motor during your run? everytime it counts a lap it gives a dyno reading as well then you can really setup a car to that tracks conditions. (just a thought)


----------



## Nutter

Hankster, I have to question your choice of IR 'gates'. IR is acceptable for indoor onroad racing, but I wouldn't count it as reliable enough to use outdoors on a muddy offroad track where it's quite likely that there will be mud covering the transponders IR reciever. Sun light also affects IR very badly, and it has quite a limited range in the sun.

I know the Orion one uses IR too, but personally I wouldn't do it "because they do". It may very well work, but my opinion of it is that it isn't reliable enough for an "ultimate" solution as you are looking to create. This is why both Dan and I have been looking at different solutions for our lap counting systems.
Myself, I'm going with a solution much like the AMB 20 system with some modifications to make it simpler, although at this stage I may still go with a solution closer to the new AMB system. Several other solutions have been considered, including magnetism/the Hall Effect, ultrasonic, and of course IR, but they all had their draw backs/complications. Magnetism was simply unworkable, ultrasonic was too expensive (it may be ok for your needs though, as you only require 1 transponder), and IR was ruled out for the reasons I've just mentioned.


-Nutter


----------



## hankster

Why? Because who is going to let you bury pickup loops all over their track? I doubt that very many track would and I can bet you 100% that our local track (R & L) wouldn't.

Besides that, you going to string pickup loops under other people's carpet tracks and under asphalt tracks? Overhead bridges won't work, that's obvious. I'm, not doing it "because they do" but because of the reasons I just pointed out. IR will work fine in 95%+ situtaions.

You are making a full lap counting and timing system. Mine is a personal timing timing system that will be very portable. Anyways, you do yours your way and I'll do mine my way... that's what different ideas are all about.


----------



## Shiloh

If you are planning to place emitters in various sections of the track, it would not be terribly difficult to build a crude but effective GPS system. You could use RF emitters instead of IR. The emitters would simply emitt a number (designating which emitter sent the signal) and a timestamp (accurate to a small fraction of a millisecond). The onboard receiver would record the number and timestamp combos while the car raced around the track. Then you could download all of that data into a laptop to see telemetry, speed through various sections of the track, etc. The computer could use the difference between the onboard receiver's timestamp and the timestamp in the sent signals to determine the distance the car was from the emitter that sent the signal. It would not be terribly difficult to implement. The onboard receiver would need to be able to record quite a few samples, though. If you had 4 emitters (one on each corner of the track) and each emitter sent several data pairs per second, the total number of data points recorded by the onboard receiver would get large quickly. All the receiver would need to do is compute the difference between its own timestamp and the timestamp of the received data packet, and then record the emitter number and timestamp difference. So each recorded entry would probably amount to one short int and one long int.

The really neat thing is that the computer would be able to figure out the track layout based on the information recorded by the onboard receiver. The computer operator would not need to tell the computer where the emitters would located or what the track looked like. The data alone should be able to provide all of that information.

Also, this design could easily be used to replace the AMB stuff. The onboard receiver could append its own transponder ID to the data packet and then repeat that data to the lapcounting computer. Then the lapcounting computer would know exactly where every car was, how many laps each car had, lap times, etc. The lapcounting computer could even display a graphic showing the cars going around the track while the race was going. With this design, the onboard receiver would not even need to have much memory, since all it is doing is receiving signals, appending data, and then sending signals. So the design could be built with an optional memory socket (like compactflash) and then racers would have the option to record all of their race data if they wanted to study it, but they would not have to incurr the expense of the memory if they did not want to.


----------



## hankster

Transmitting and receiving "data" is A LOT more expensive then just using an IR detector and onboard processing. No way to keep it under the $100 target price if RF is used.

The big problem with RF is that it is omnidirectional so it is very hard to control the area of the track where it would be picked up. Let's remember that you may want to cover an 8' wide area of the track for counting the lap and the other side of the board is only a couple inches away. It is diffecult, if not impossible, to tell the RF receiver to only pick up the signal 0 to 8 foot from the becon and not 8'2" away.

This isn't something I've just thought of. I've looked at this long before Orion ever came out with their system. I've looked at IR, RF, magnetic and even laser communications. IMHO, IR is the way that will work best for what I am trying to do.


----------



## racerrandy

hankster sounds like you are on the right track to me. All I need to know is how soon can we expect it. I will be the first to step up.


----------



## NatureBoy

A micro ear phone similar to cell phone to listen to your lap times as you drive would be a plus if you could get the lap counter to "talk". Why not it is the ultimate?!:thumbsup:


----------



## Moo-Shoe

Hehe... I can see it now... The talking lap timer that insults you as you drive around the track...

"Wow! You call that driving?!"
"My grandma could out drive you in her wheelchair!"
"Pick up the pace, sonny, or you might as well pack it up!"

hehe


----------



## hankster

I would really hate to put a date on any release because that only means I'll miss it for sure. I will hopefully have a "close to final" version the beginning of January.

Hehe.. that is funny! Maybe for the "cost is no object" version!!!!


----------



## Shiloh

Hank, I realize that RF is omnidirectional. That is why I commented that RF would be the way to go for a crude GPS style solution. Each emitter would broadcast its own number and a timestamp. The receiver in the car would also have a timestamp. The difference between the car's timestamp and the timestamp of the emitter would be used to determine distance between receiver and emitter. This would be the foundation for a simple GPS style solution. With three to four emitters, accurate GPS style information could be generated. If you are going to section off the track with a bunch of emitters, a GPS style solution might make sense.


----------



## TopRowSeat

If there's any way I can help please let me know.

I'm excited about a more affordable personal lap timer
for testing.

SteveMc
[email protected]


----------



## DynoMoHum

I like Shiloh's idea... now if we could just get the US military to think of a use for it... they might build it... It could potential put ABM out of business...


----------



## hankster

As I said, transmitting and receiving data via RF is expensive. Just an example, an IR pair (transmitter/receiver) is about 3 bucks. A data transmitter/receiver pair is about 50 bucks. Add the cost of 2 or 3 more transimtters and you are well over $100 just for transmitter/reciever set. Now let's add in the other hardware needed and you are over $200... not very inexpensive.


----------



## hankster

Just to add, Shiloh's idea is not off the wall but can be done much less expensive. With $5 worth of parts (plus extra memory, but memory is cheap) you can get much more info. Here's how.

Monitor speed (rear wheel RPM), steering position (via the rc receiver/servo connection) and lap time. You can then plot any point on the track. A little fancy software work can take those 3 items and draw the track. When the data is plotted in the software you can point your mouse pointer to any data set and it would show you your position on the track when those data points were taken.

Sound too far out? It isn't, that type of system is already being made for karts and full size cars. Doing the actual hardware is easy, the hard part is the software to change the data into the track.


----------



## Dan the Man

hankster said:


> *A data transmitter/receiver pair is about 50 bucks. Add the cost of 2 or 3 more transimtters and you are well over $100 just for transmitter/reciever set. Now let's add in the other hardware needed and you are over $200... not very inexpensive. *


Well, compared to $4000 for AMB...

For a personal system, I think you're right, IR is the way to go. It's what the LapDragon guys did. It would also be a pretty good approach otherwise.

My reasons for using radio in FreeLap have been explained before, but with the closing of the Full Throttle track, I'm going to wait and see if the rumored new track will be run dry.

The Linx LC chips I found for the FreeLap system are pretty cheap, less than $10 for a Tx and just over for an Rx. But their data rate isn't quite high enough to suit me and therefore collisions may become a problem. http://www.linxtechnologies.com It's possible to have two transmitters go at once and have a receiver get both of them, but it requires some data processing that I didn't want to deal with.


----------



## hankster

Dan, I never said that RF was wrong for a full blown timing and scoring system, it was others trying to say that it would be the way to go with a personal timing system that I think are wrong.

Anyways, I have no plans, nor do I want to, design or make any type of full blown timing and scoring system. With the things I have in my design book, it could keep me busy for a looooong time. :thumbsup:


----------



## Synthboy

*Another alternative to Orion*

There already is a personal lap counter besides the Orion system. It's called the Lapdragon system. The price is very low($80). It uses infrared and is totally self contained(no need for a PC).

The web site is www.lapdragon.com

-BC


----------



## Dan the Man

To be fair, LapDragon is not without its own limitations, not the least of which is the need to stop the car to read your lap time.


----------



## Guest

Dan the Man said:


> *To be fair, LapDragon is not without its own limitations, not the least of which is the need to stop the car to read your lap time. *


Dan - I'm not sure I see how this is a limitation. Are you suggestiing there is some sort of advantage to being able to read lap times *while driving the car* ?
Jep


----------



## Motor City Hamilton

Hank - I didn't read all the posts, so please excuse if this has already been mentioned. I would like one that could take readings from multiple points around the track. I don't care if it is from 3 different boxes that have to be laid around the track. I run only road course. From the current personal lap counters, I can see that I improved my overall lap time, but where did it come from (straight away speed, hairpin tight turn car set up at one end of the track or sweeper/mid tight/90% on power steering set up. Then I would also know if I lost something in the set up.

I don't know how you would do this, but I.m not an electrical engineer. Maybe the data would have to be captured in three seperate boxes then loaded into something else to compare data points?

You build it, I'll buy it.


----------



## Dan the Man

Jep - yeah. Especially when you're trying to choose lines, or if driving on an oval where you have a fresh lap every seven seconds and pulling the car off is inconvenient.

This is why most systems put a dumb transponder in the car and put the data processing trackside...

Lapdragon also has trouble with direct sunlight.


----------



## hankster

Split lap times seems to be an often requested feature. I plan on having that in my system.


----------



## Synthboy

Any system that uses Infrared technology can have problems with direct sunlight. There is no way to prevent this except for being careful where you place the transmitter/receiver zone. If there is a shady spot near you track, it would be best to have the car pass the transmitter there. It usually isn't hard to orient the sensor away from the sun. 

As I said, all infrared systems are susceptable to sunlight including the Orion system(their manual even mentions this under the section on Environmental Influences). It doesn't mean the system will not work, but care should be taken to minimize direct suinlight on the sensor.

Brian


----------



## Synthboy

Regarding split lap times, there is a way to do this using the Lapdragon. You would need extra transmitter beacons, but then you could place them in different areas along the track. For example, if you wanted to know how fast you are going around a hairpin, you could place one beacon at the entrance to the hairpin, and one at the exit. Then, your laptimes would represent the time it took to get through the hairpin.


----------



## Dan the Man

I think the "line" for an IR system ought to be above the track, not to the side, to avoid being blocked by other cars. You could build it into a tunnel (trackwide, maybe 2' long and 2' high) and thereby provide shade as well.


----------



## Fred B

Just a note on IR...The orion system seems to have a little bit of inaccuracy depending on where it's placed on the track. The receiver picks up a cone shaped area of the track, if the car is close to the receiver, it scores close to the middle of the "cone". As the car passes farther away, it's further out on the "cone" and is scored earlier.

The point is that it's not really a problem but the receiver should be placed at a point (or points) on the track where the car will be passing at approximately the same distance each time.

FB


----------



## hankster

My system will eliminate that problem. It's pretty simple to solve, I'm surprised that Orion didn't do it themselves.


----------



## Dan the Man

Optics? Or were you planning on lining up the sensor cone?


----------



## hankster

I'd rather not say right now, but it won't be a problem.


----------



## jjordan2

I don't know if it's been mentioned before, but how about palm connectivity??

On the orion site, they show an IpaQ handheld connected to the Orion unit to store the lap info for later use.


JAy


----------



## Dan the Man

The port on the bottom of a Palm Pilot is an RS232 port, and you can get cables to hook them up to a DB9 plug. So the problem is mainly in making the software.


----------



## jjordan2

I own a Sony SL-10, so it my be more difficult to find a serial adaptor for mine. Is there a way to convert a USB port to work as a serial port??

The Ipaq adaptor looked very useful tho!

JAy


----------



## calvin

You can buy a USB to serial port adapter, but unfortunately they do not seem to be universal - why, I don't know. I was trying to find one to use with my GPS and I ended up buying three different ones before I found one that would work with my laptop and my GPS. Some of the others would work with other serial devices I had, but not the GPS and vice-versa.


----------



## Dan the Man

If you can get a serial cradle that will also work. It's what I did with my Handspring. It needs a little modification from the basic pinouts. The setup uses the PC, not the Handspring, to power the serial port. You need to give a few pins +5 to attach it to anything else besides a PC.


----------



## Ennjay

The system would already have Infrared and every palm has IR. Why not just program the system to send the info via it's IR port to the infrared port on your palm. That would be cool.


----------



## jjordan2

That would be great, but I don't know if the Orion unit would let you do that. :/


JAy


----------



## Ennjay

No, but Hanks could.


----------



## hankster

The Orion trackside unit has an IR receiver but no IR transmitter, so it could not communicate with a Palm. In fact, it is not just as simple as using an IR transmitter to communicate with a Palm... there is a lot more going on.


----------



## SecretSquirrel

Hank,

You seem to have a good understanding about a lot of this. Do you have any designs for a smallish 100 Hz datalogger circuit that would do 2-4 channels (SE or Diff)? I have looked, but they either sample at about .5 Hz or need power from a PC (USB powered).

I will pay 

Thanks
SS


----------



## Dan the Man

The thing to do would be to start with a microprocessor and attach a large wad of EEPROM. You can upload to a PC via serial. Sense the servo commands from the pins, use an A/D chip for voltage and a Hall sensor for current. Sounds like a good project, but not one I want to tackle while the other things are unfinished...


----------



## hankster

It would be pretty hard to go at 100Hz, the amount of data to be stored would be huge. That is about 200K of memory required per minute. It is 400 pieces of info per second so you are actually looking to operating at close to 4000Hz with the overhead (read, convert, write, etc.). 

Something that samples at 5 Hz would be easy with 10Hz not much harder. Of course it would all have to be custom built... very doable but would take some development time. To make sure there are no problems a seperate battery pack would need to be used. Not really that bad as many already use a receiver pack and that could do double duty to power the unit.... 6 cells would be better then the 5 cells that are normally used.

What I am actually looking at doing is making a "real time" DAQ where the data would be transmitted via RF to a computer in real time. Then you could let the CPU run at full speed and sample as fast as it, and the program, would allow and not worry about data storage. I figure it could do 6 channels at least 50 Hz, most likely more.


----------



## SecretSquirrel

Hank,

This is something that I believe could be VERY useful to R/C car racers. The Miles brothers have done something themselves, but I hear it has been fairly pricey. I would like to work this out, but circuit design is for me.

If you plan to develop this for sale, keep me posted. If not, consider what you would charge me to make a couple units.

Thanks
SS


----------



## Dan the Man

Above post should say "microcontroller", not "microprocessor".


----------



## hankster

The plans for anything I design will be freely available to anyone. I may offer a "parts pak" that would include everything needed to make it. That would save someone from having to buy from a half dozen suppliers and would also include a circuit board to mount everything on. My guess is the cost would be less then $300


----------



## Fred B

From what I've seen, you'll need at least 10Hz to see what's happening on the track. Especially for the oval guys.


----------



## DynoMoHum

I want a RPM sensor on my personal data logger... I thinnk with RPM I could tell most of what I'm missing... Voltate and Amp would be nice too, but I could likely live without that, if we were talkinga bout something cheap... 

Oh wait a minute... this is the personal lap counter thread... could you throw a RPM logger in with it?


----------



## DynoMoHum

I was kind a joking in my previous post... however after I've thought about it a little more I really think that if there was a way to record RPM and tie it to the points where the car passes one of the sensors on the track I could lean alot about how to gear a car, and how to improve my driving. 

In oval I would use two snesors, comming out of a corner, and the other at the end of the straightaway. You could get lap times, and sense the RPM at the fastest and slowest point on the track.... I beleive this would be a great help for oval racers... I think a simmilar thing could be done in road course as well... but it would take more sensors, and/or you'd have to work on one section of the track at a time.


----------



## TopRowSeat

> _Originally posted by hankster early in this thread:_
> *My guess is you should be able to buy everything for well under $100 and most likely under $75.*
> _Then just recently:_
> *My guess is the cost would be less then $300 *


Hank, I sure would like the first price range a whole lot better than the second one.

Will it be possible to get the absolute basic version close to the original price point and then add on features which would carry it up to the second price point?

Is the price change a reflection of the cool ideas here or of the basic unit itself?


----------



## SecretSquirrel

Those are two different conversations.

His LAP timer will cost < $100

The Datalogger I want to make will cost around $300.

Hope this clears it up

SS


----------



## hankster

I guess it could be made upgradable but I think that having one unit that is upgradable would be defeating the purpose of the basic lap counter. If we drive the price up to over $100 then they might as well buy the Orion or LapDragon unit.

Adding on the extra circuits on the basic unit (plus a more powerful CPU) that would be needed if we wanted to make it upgradable most likely would put it over $100.

I think everyone would be better served with seperate units. So you buy and build the basic at $75.00. When you want to move up you sell it for $50.00 (or more because it is already built) and use that towards the purchase of the DAQ.


----------



## hankster

As a note: I have all the hardware on hand to build the lap counter. It's doubtful I'll have a bunch of time to work on it this week, but plan to hit it hard next week. I hope to have a working prototype by the end of next week.

Also, I have about 75% of the hardware needed for the DAQ and a rough plan on how I want to do it.

Once we get close to having a final version or the lap timer I will be opening a new web site to support this and all other "RC Tech Series" projects. I'll announce it here when we get that close.

As I stated before, all plans, hardware lists and instructions will be posted on-line and will be freely downloadable. What I would like to do is offer a "parts pak" that would include everything needed to make the units. The advantage of buying the "parts paks" would be you would know for sure that you are getting the correct parts and you would have one place to buy everything. Otherwise you would have to buy the parts from a number of different sources making it harder to do and most likely more expensive.


----------



## Dan the Man

May I ask what kind of chip you're using?


----------



## hankster

I'll be developing using the Basic Stamp.


----------



## Dan the Man

That's one of the chips I considered for mine as well, since it's easy to program. But for something I wanted to make ten or more of, I didn't like the price... Then I sterted looking at what it takes to program PICs and chickened out.

For my system, with most of the brains in the trackside computer, its data transfer wasn't fast as I wanted either. Since you're not worried about multiple cars that's not a problem. And maybe I'll go back to it anyways.

I'm eager to see how it turns out...

For those who don't know...
http://www.parallax.com/html_pages/products/basicstamps/basic_stamps.asp


----------



## hankster

Yep, there are a number of problems with using a Stamp if you want to do multiple cars. It's even pushing things when making the DAQ, mainly writing to EEPROM. 

That is why I decided to go with the RF transmitter for the DAQ, I think I can push out the data fast enough to keep the sample rate up. And it does eliminate the need for all the memory. I think the saving in not needing the extra memory will offset the cost of the RF end of things... plus it'll be so cool to see the data on the PC screen as the car is running. If I need more speed I can always go with the BS2-sx or BS2-p


----------



## Dan the Man

You can use the pulsin command to measure servo/throttle positions. These should happen in succession, so you can read one, the other, then whatever other sensors you've got (voltage, current, whatever), then repeat. This will give you about a 20 ms refresh rate. You can program in a delay if you want to slow it down.

I have to recommend the Linx LC chipset for RF. It's just way too easy. Rx and Tx both just have power, signal, antenna, ground. You use the serout command from the Stamp to the tx, and feed the Rx's signal wire into the computer. It's a LITTLE more complicated than that but not much.

In fact you should find that the FreeLap first-gen receiver box is exactly the same as what you want for yours.


----------



## hankster

Yes, I know all about using PULSIN commands. Not sure what Tx/Rx set I'll use yet. There are many and some do have advantages over others. I'll most likely use the Javelin Stamp for the DAQ since it will eliminate a lot of external circuitry.


----------



## Dan the Man

Parallax was selling Tx and Rx kits for the Stamp that were based on the Linx LC chips, but again, I didn't like the price. Those and similar, here:
http://www.parallax.com/html_pages/products/communication/rf_modules.asp


----------



## GareySmiley

Well since everyone is talking about this I just can't keep my mouth shut. I've been working on this for two years now. You can see some of my progress at http://bigboy.slink.com/Telemetry/
. I was planning to make this a commercial product, but since Hank is doing one now for free I may scrap it. I've already got to much time and money wrapped up in it.


----------



## hooked911

why dont somebody make a wheel dyno?? One that measures data from the motor and the car wheel at the same time. I think this would be more usefull than a regular dyno.


----------



## SecretSquirrel

Gary,

You have some great ideas. I have used several versions of your Lap Timer and I like it. Good luck with the Telemetry system. I am afraid to ask how much you have invested in that project, but it looks SWEET!!

Your Lap Timer Beta 11 expires on 12/1/2002. Do you plan to issue another beta release or a final release?

SS


----------



## hankster

Garey, No use to stop work, I feel the more the marrier. BTW, maybe we can do something with using what I want to make and using a Palm instead of a PC... at least with the Lap Counter. I think that would be very handy feature to have.


----------



## hankster

As an added thought on the reason for using the Javelin Stamp instead of the Basic Stamp even though it is more expensive. Much of the needed software is already built into the JS. It already has an AD converter (needed for voltage and amp readings), it has a built-in timer for lap timing and the big one is the built-in power supply should be able to power everything with power from the receiver. The only problem is in 4 cell cars as the voltage is too low, but then most 4 cell racers use an external receiver pack that should work.

All of this means that very little extra circuitry would be needed. I can see a few resistors and a few caps on the circuit board and of course the additional external sensors. Should make it easy for anyone with good soldering skills to make.

The size should not be much bigger then a 24 pin DIP package which is about 1.5" long and .75" wide.


----------



## JeffPatch29

Hank, I am very interested in the completion and progress of this project. I think it is about time someone came out with at least the system and parts to make a DAQ Unit or cheaper lap timer. I was wondering however, this is a little off topic, if anyone has ever tried or considered hooking up 4 digital scales together, and wiring them through either a serial port or usb port on a pc, to get instant readings from the scale to a program that could calculate cross weight, or other usefull information pertaining to weight transfer. Maybe add other equations to calculate roll center, center of gravity, stuff like that. I understand your busy with your project and am looking forward to seeing it completed, but maybe someone else has looked into this, or has thought or will think about it? any replies appreciated, thanks. -Jeff Patch


----------



## hankster

Jeff,

Hehe... your jumping ahead a little here.... or maybe a lot. One of the projects on my list is a "portable" scale system that would use 4 small pressure pads that could be placed on any hard surface and used as a scale. It could be fed into a PC but using an LCD display would be better 'cause then you wouldn't need a PC to use it. Advantage of a PC is that the data could be stored. That actually is a pretty simple project to do. Cost about $150.00

As an expansion of that would be to build a "wind tunnel" so you could test the effect of different bodies and body placement on your car.

Lots of ideas but not enough time.


----------



## JeffPatch29

Hank, I am loving the ideas. I almost think you should get a couple of guys like your self and start your own high tech r/c equipment company. Who knows how much money you could make and how far you guys could advance the sport. Keep us posted on progess of the lap counting system and DAQ, can't wait to see them when thay are done, take care. -Jeff Patch


----------



## hankster

If I had a few hundred grand to start a company to fully develop this and market it I would... :thumbsup: 

Mainly this is fun for me. If I can offer what I have found to others and they get some use out of it, that's great. Hopefully those that find the info useful will buy the "parts paks" from me so I can at least support HobbyTalk and maybe even buy a few extra RC goodies.... I'll be really happy.

The way it looks I'll have to buy at least 10 of everything to even get a 10% discount. That means for a $300 system I'll have to put out $2700.00 to buy the parts. Now lets put together some instructions, build the web site and answer questions. If I can make $300 on 10 systems a month that will at least cover the server bills to keep HobbyTalk up and running.... that's all I want anyways.


----------



## Moo-Shoe

Hank, I think before you put up any cash of your own, get to a "production model" and have it ready for the Parts Pak. Then you take orders with a deposit and figure out how many will sell. That way, you're not putting up a ton of your own cash up front.

I'm not sure I'd be that interested in the DAQ, but I'll buy a lap timer from you when that's ready. 

Oh... If you're really interested in starting up a company to make this sort of stuff, why don't you look into getting a government loan/grant to start a small business? They're looking for ways to jump start our economy and I'm sure you could get pretty decent rates on a SBA loan.


----------



## TopRowSeat

*Waking up the thread*

Hey Hank, any progress report for us curious folks?

Interested in how you're making out, if you've had
time to work on this more.


----------



## rowle1jt

I would be interested in one too.


----------



## hankster

I have done some work on it. Got the basic programming done with a bunch of fine tuning to go. A few other things have been taking time away from it and I have not been able to do a bunch lately. Right now I need to get a few extra parts... I've been laid off since Dec. and still have not received an unemployment check from the state (applied 3 times and my application has been lost all 3 times somehow)... and it seems that the FOC (friend of the court) doesn't like when you fall more then 4 weeks behind... right now I'm just happy to be out of jail!


----------



## drave

Sorry to hear about your luck Hank, I'm sure things will turn around for you though. I've just found this thread tonight, and I must say that I am very excited. I have been thinking about trying to implement a ir transmitter/receiver set with the M8's laptiming function, but haven't had enough time to play around with the idea(similiar to the Orion, but using the transmitter). I have to say the idea of buying all the parts and making the unit myself is very appealing to me, I'm not a electrical engineer, I do have a BS in Engineering(would be an EE if I had it to do over again:devil but I do have electrical background. If I can assist you in any way in this project, please let me know, I've been contemplating buying the ORION system, but like everyone else here that I can see, was displeased in it's performance for the price. Interval timing is somthing I hadn't thought of having, but would love it in a PLCS.
For now I'm just wishing that someone would incorporate a wireless network with the AMB timing system used at most tracks, so I could do my test, then download the data from the LCS to my laptop via the network.


----------



## rowle1jt

Hankster, I hope things turn around for you......soon.


----------



## drave

Just thought I would bring this thread back to the top for everyone........... Hank, how are you, have you had time to work on this project any further??????????


----------



## hankster

I've had a few bumps in the road. Most noted is that it took 7 weeks to get my first unemployment check. Needless to say that put the hurts on buying parts I needed to complete the project.

But using parts I already have I have been working on a programmable discharger. It will discharge at whatever rate you want (50 amps or more) and what cutoff you want. It will graph out the discharge curve, figure the average voltage and save the data to a file.

Not sure at this time how many samples per second will be done, right now it is doing about 50 per second which is really way more then is needed. I may cut that back to about 10 samples per second.

As a note; It uses an ESC (user supplied, any cheap ESC will work) to control the discharge rate and light bulbs (user supplied) for the load so you could, as an example, put 25 bulbs together if you wanted to discharge as high a 40 amps. The load is only limited by the number of bulbs and what the ESC can handle.

For an example I am using a load that has 20 bulbs on it. If there was no control it would discharge the pack at about 37 amps. We sense the current draw and adjust the ESC so the discharge rate is whatever is programmed into it.

I figure the cost to build, not counting the ESC (which most people have an old one laying around) and the bulbs will be about $80.00. Not a cheap project but it is an interesting one.


----------



## DynoMoHum

Sounds cool Hank... I think it may have more then one use...

Have you tried using a old stock armature as the load, dip it in ice water to keep it from going up in smoke???


----------



## hankster

I haven't tried that but any load should work since an ESC is being used to control the load. Heck, if someone wanted to make a resistor bank that would work fine too. Just light bulbs are easy, cheap and everyone knows how to use them.

You should be able to take it to the track and use it without a computer hooked up to it for those that don't have dischargers built into their chargers. Of course you wouldn't get data but at least you'd discharge your batteries.


----------



## DynoMoHum

The alternitive uses I was thinking about...

First... a way to test a ESC at high loads...

Second... A way to really deep cycle batteries... but that really is I belive what Hank's orginal intent for this device is. 

Oh... third might simply be to get a really good idea about how much voltage drop you see on a perticular pack of batteries at some heavy amp load. Presumably the lower the actual IR of the battery, the higher the voltage should stay under heavy load.

Bascily... I'm really interested in this project Hank... I think it's got alot of potential uses for someone like me.


----------



## hankster

It could be programmed a lot of different ways. The basic setup will be a linear discharge. I'll make it fairly easy to change this. It will not have "external" adjustments, the program itself will need to be changed and then the microprocessor reprogrammed. That is easy to do and the code will be well documented.

I am doing it this way to keep the costs down while allowing fully adjustment. If we get into LCD displays and such it can drive the cost up quickly.

The nice thing about being able to reprogram the microprocessor is that once the hardware is done, it could be programmed to do a bunch of different things. Such as my previously "manually done" Oval Tests or even setup discharge profiles to vary the discharge rate during the discharge.

On the graph you can move your mouse pointer over any part of the graph to get the voltage/time reading at that point of the graph. You'll be able to share your raw discharge data with others so they can look at it in Excel or even in the graphing software (a free download).

Of course everything will be available on line, including the programming. Others that know how to program the Basic Stamp will be able to offer their own programs so that others can download them and try them out. Heck, hopefully they can even improve on my "stock" program... almost like an "open source" project where we all contribute.

It's turning out to be a cooler project then I first thought and there are a lot of possibilities. The hardest part is the signal timing for the ESC. The microprocessor can only do one thing at a time so we have to make sure that the ESC doesn't get "lost".

The ESC requires a "control" signal once every 10 to 15 ms. So I have to:
1) Send the ESC the control signal.
2) Check the amp draw and voltage then figure if the amp draw needs to be adjusted. Also check for the "cutoff" voltage and stop the progrom if the cutoff is reached.
3) Go back and send the ESC another control signal (within 10 to 15 ms of step 1) to keep the amp draw correct.
4) Send the data to the computer for graphing.
5) Go back to step 1 within 10 to 15 ms of step 3.

So we can see that the amp draw is adjusted about 50 times a second and data is sent to the computer about 50 times a second. Really, that is just too much data for most people's use and I most likely will reduce that to about 10 times per second. That is still 4000 data points for a battery with 400 seconds of run time. I guess if someone wants 40000 data points we can offer that too. That high data rate might be useful for tests.


----------



## drave

Cool, sounds like a nice discharger. So, when do you think you'll be able to post some plans for the lap timer?? A simple design would work for now, as long as I could upgrade it.


----------



## hankster

At this point I have no idea on a lap timer. That most likely will be the next thing I'll work on.


----------



## The Adjuster

*Programmable discharger*

I have been having the same thoughts. I was going to set up mine as a simple voltage regulator with the load determining the current draw. I set up a program flow chart. My only problem now is teaching myself how to program the PIC. During college, we learned how to program Zilog Z80s, and it was something I found interesting. According to a couple of people I have talked to, the modern PIC is quite nice to program.

I guess I will have to get reading again...

Phil


----------



## hankster

I am going through a small redesign in the discharger. I was using an 8 bit A/D converter (changes analog signal to a digital signal) but I don't feel the resolution on the readings are fine enough. I am going to a 12 bit A/D converter.

That will let me get down to .02 on the amp rate and .002 on the voltage. I didn't want to go with a 12 bit ADC as it is $5 more expensive then a 8 bit ADC but I think in the end the extra cost is work it.


----------



## Roadsplat

Just wondering if what became of the Personal lap counter you were working on? Did you complete the project?

RC


----------



## samgkd

*Talking Lap Counter*

My Brother and I worked on a lap counter that would speak each lap time to you through a pair of wireless head phones. It used a mini LED transmitter plugged into the car's receiver that sent a coded signal to a tripod mounted receiver beside the track. The receiver was plugged into a laptop that done the timming and produced the voice. The sound came out of the sound card into a wireless transmitter. My brother done the programming part and I done the electronic part. I quit racing and the project died.


----------



## hankster

With the introduction of the RC Data Recorder I decided not to go any futher on the project. A lap counting add-on should be the next item they develop for it.


----------



## Roadsplat

Any idea how long before something like that will be released?

RC


----------

