Affordable lap timers

[notme]

Cool. No, that's smart. Not only is there the physical hardware, but even more stuff to inevitably debug in software. That's always the hard part -- deciding what features are absolutely necessary and sticking by them.......

Abso-bloody-lutley! Been there done that got the scars to prove it.

I know if I had one, I'd end up opening it up and plugging it into my JTAG ICE to get the data, but I'm a geek, lol.

Indeed you are, my friend! However, it's quite likely that I'd give you the source code if you wanted to play with it. :-)

What's the story with the IR? I take it you need direct line of sight? At that speed, how much time have you got to send the signal -- if you want 10 codes, say, is there enough accuracy with IR to use DPSK or something? How do you encode stuff onto an IR medium?

The whole technical story of the beam detection is too much to explain in these forums (and too boring!) but basically if you go thru the beam faster than 300km/h you won't get a trigger. If this is a problem for you (!!!!!!!) simply put the transmitter on a slower part of the track.....which brings up a point - if used on a bike as opposed to a car or gokart or whatever, the recevier needs to be on the side of the bike that faces the transmitter when you pass it. So, you can't have the transmitter on say a hairpin, because you will be leaning and probably miss the tx.
Somewhere along a straight will be the best place, most likely at the start/finish or on the pit wall.


As for the encoding....think QPSK

[notme]

I'm in.

Can we read the screen while on the bike? ie. see what we did that last lap?

Heya dude!

Short answer is no - for a variety of reasons.

Reading the display while on the bike means a few things that make the design more complex (and therefore more $$$$) such as a sensor that can be mounted remotely from the display, a backlit display for high contrast, big, easy to operate buttons for gloved hands, etc. Also, central to the operation of the unit is that when the bike passes the transmitter, the receiver "sees" the transmitter, so that means the receiver has to be on the side of the bike facing the transmitter rather than up where you can see it...

The units both have mounting tabs (see photos in first post) so they can be cable tied/screwed/velco'ed or whatever to things. I imagine the transmitter being sat on the pit wall or a box or something like that, and the receiver screwed to the bike (anyone mind a small hole in race fairings?) or cable tied, or velcro'ed.

Some of these things are not ideal, but again, that's why I am able to build them so cheaply.

My Birthdays coming up. One of these has got to be better than a pair of socks! $100 depoist and the balance before delivery?

Racey

Yeah something like that i guess. We will have to organise something - PM sent.

[notme]

I'm hemidemisemi interested. Would be good for dirt riding and such. Just I wouldn't be able to give you a hard cash deposit anytime soon

Really? Never would have thought dirtybikers would be interested.....do you do laps of a something like a motocross park?

Another compromise that has been made in the design is that it is NOT sealed, so it can't be used in the rain, and I'd be hesitant to use it in a really dusty dirty environment.....depending on demand I can take care of the dirt issue but it will never be a wet weather timer without a more expensive (sealed) case unfortunately.

[Coyote]

Really? Never would have thought dirtybikers would be interested.....do you do laps of a something like a motocross park?

Another compromise that has been made in the design is that it is NOT sealed, so it can't be used in the rain, and I'd be hesitant to use it in a really dusty dirty environment.....depending on demand I can take care of the dirt issue but it will never be a wet weather timer without a more expensive (sealed) case unfortunately.

I'm sure a few dirt riders would like an accurate reading how how quick they're going on their local mx loop. And me and my brother could compete with each other on the same bike

I'm sure a plastic bag would work

[notme]

Good idea(both of them..)! And that's exactly the sort of thing that makes this cheap, is people being prepared to stick a plastic bag over the unit instead of paying lots more for it to be sealed.

[Skunk]

This sounds good. I'm interested...

Does it stand up to vibration well?

[notme]

This sounds good. I'm interested...

Does it stand up to vibration well?

So far so good..... has been designed with all industry standard methods, and tomorrow I have time booked on our whiz bang vibration machine to shake it till it breaks it.

[boomer]

nice work Allun.. if you/they are around in the not so distant future i'll have one.

thumbsup to you sir!

[notme]

Cheers!

Will be around for a while don't you worry....

I'm (pleasantly) surprised at the lack of negative responses along the lines of "it's too big" or "it's too ugly" since usually with my product designs the cosmetics are reasonably high priority!

Or is it just that for once the target market is less interested in pretty bits and more in using this as a tool? Sweet!

Here's another few photos to get an idea of size and possible mounting points on my SV....as previously mentioned, if you had race fairings and didn't mind some small screw holes or sticking velcro to the fairing then that would be ideal, otherwise it has to be cable ties i guess.

Oh - note that the pix show the transmitter unit - in reality you would attach the receiver to the bike, but the receiver prototypes are in use at the moment so i grabbed a transmitter. They are built in the exact same case - again because it cuts the cost to buy all the same cases.

[R6_kid:Me]

I'm (pleasantly) surprised at the lack of negative responses along the lines of "it's too big" or "it's too ugly" since usually with my product designs the cosmetics are reasonably high priority!

Or is it just that for once the target market is less interested in pretty bits and more in using this as a tool? Sweet!

to quote an american forum "style is for posers"

looks a bit chunky, is there much room for minaturisation? Does the pickup need to be able to 'see' the transmitter or can it be in behind a fairing?

[jonbuoy]

Great idea mate but I think you would sell more if it had a display to let you know if your getting better or worse times without pit crew relaying it to you.

[Drunken Monkey]

Yeah man, looks good. I would just want something functional, I don't mind keying data in manually (already doing that with my G-meter anyway). Got any for demo?

[Shaun]

Great idea mate but I think you would sell more if it had a display to let you know if your getting better or worse times without pit crew relaying it to you.

Exellent work mate, I agree with the above post 100%

[notme]

to quote an american forum "style is for posers"

looks a bit chunky, is there much room for minaturisation? Does the pickup need to be able to 'see' the transmitter or can it be in behind a fairing?

Miniaturization = cost goes up.

The biggest factor there is actually the LCD....

To give you an insight into the tortured mind of an electronics design engineer:

-I need an LCD.
-I need at least 2 lines, 12 columns (worked out based on the application)
-Closest standard LCD is 2X16, so that's what we choose because standard off the shelf = cheap.
-The LCD must use the type of interface I need, so some of them are out.
-This leaves a small selection, so choose the cheapest.
-This LCD has minimum width of x, so the case must be at least x wide.
-Case must be plastic for easy working and readily available in small qtys
-Nearest standard case comes in a size that is too small, and a size that is a bit too big. Choose the one that is a bit too big.
-Case needs to fit the battery inside, and the case above does not (too shallow)
-Choose next case size up, now case is quite large.

So at this point the case has a lot of air in it, but without choosing to make the circuit more complex to run off a different battery (it's a 9v batt), or finding a more expensive but more compact LCD, or a custom case.... you get the idea.

The only way I can hold the price to $200 is by having a lot of compromises....one thing i can say is that there are few compromises in the electronic design and software!

Crappy packaging, but a good heart.

Hey, if a lot of them sell, I will be able (and willing) to put some money into making some improvements. And having said that, after a few people have tested these at the track for me, there might be enough interest to justify me doing some of the improvements before the first version even rolls out the door.

A few very small things would make it a much better product - like a label!

You wouldn't think it, but a simple label professionally printed would make this thing look better, would make the buttons semi-sealed and thus splashproof and dustproof, would make the case drilling easier (less accuracy needed) and would stand up to wear and tear better than the paper ones.

Anyone got favors to pull at a label printing place?

[notme]

to quote an american forum "style is for posers"

looks a bit chunky, is there much room for minaturisation? Does the pickup need to be able to 'see' the transmitter or can it be in behind a fairing?

Opps forgot to answer the last bit, sorry G!

It's optical - the transmitter and receiver need to look each other in da eye when they pass.