EtherTen + 2xDMD = Swim Club timing board!

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Simon
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EtherTen + 2xDMD = Swim Club timing board!

Post by Simon » Thu May 10, 2012 2:11 am

Just thought I'd share my project of the last two weeks.

For the past couple of years I've been helping run the regular Sunday morning encouragement swim events at my local swim school. When my three boys started going along, the events were being organised and handicapped on the fly from print-outs of an Excel spreadsheet recording times and personal bests of each swimmer.

Pretty soon I started putting together a MySQL database and web site (using Perl, Catalyst and Mason2) to manage the meets, all the way from swimmer registration to handicapping and producing timesheets, programs, and the rest.

We've been running this system for about a year now, but our timekeepers for each lane still use stopwatches and record times on paper, so I've been toying with ways to improve this aspect of the meet management and reduce my time in transcribing results and eliminate errors.

Enter the EtherTen and the DMD displays :)

What I've built is basically a timing board using two DMD displays vertically, the EtherTen, a cheap plastic horn and Jaycar amplifier and a bunch of switches mounted in Berocca containers for the time keepers. The Arduino fetches event information from a custom daemon on the web server, times each race and submits each swimmer's time and placing back to the server. Voila, live online timing!

The board gets its first outing "in production" this coming Sunday, and with any luck I'll get some photos and video of it in operation which I can share if anyone's interested ;)

I'm already dreaming up version-2 enhancements - primarily, wireless control for the timekeepers and starter. Just gotta figure out how to do this easily, cheaply and reliably.. but I suspect the old maxim of "easy/cheap/reliable - choose two" will apply :lol:

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Simon
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Re: EtherTen + 2xDMD = Swim Club timing board!

Post by Simon » Mon Jun 04, 2012 12:48 am

I don't - every week I intend to whip out the phone and get a video of it in action, but I'm so busy marshalling swimmers that I never get a chance :lol:

If I get a spare moment one evening this week I'll set it up and take a few photos and videos.

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Simon
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Re: EtherTen + 2xDMD = Swim Club timing board!

Post by Simon » Wed Jun 06, 2012 12:48 pm

OK, so I've taken a couple of photos of the timing board tonight :)

I made up a simple frame out of 38x19 pine, with a 4mm polycarbonate "screen" siliconed into a rebate in the front, in a (rather vain) attempt to keep the very humid atmosphere of the swimming pool out of the electronics :)
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On the rear I mounted two Clipsal 2000-series face places I had lying around. On the blank one I cut out openings for an IEC power socket and power switch (recycled from an old PC power supply), the banana plugs for the loudspeaker and an opening for the DB15 connector which connects to the lanekeeper's and starter's switches.

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Internally, we've got two switch-mode power supplies - one 5+12V from a dead external USB HDD enclosure to drive the EtherTen and audio amplifier, and another 5V 5A supply to drive the DMDs. I considered using the 5/12V supply for both purposes, but figured I was getting too close to its current limits with the two DMDs so opted for a dedicated 5V supply for those. So far there's been no power issues at all, so I think I made the right decision :)

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Hot glue guns rule :) I'm not sure how I could have mounted all this in such a small space without one! The EtherTen is hot-glued to its PET shipping packaging which is in turn hot-glued to the DMD. Everything else is hot-glued in place too :lol:

At the swimming centre I've permanently installed wiring for the lane keepers' and starter's controls, using recycled CAT5, telephone and alarm cabling terminated at the timing board with a DB15 plug, and using a 5-gang RJ45 wall box at the other (one socket for each of 4 lanes, and the fifth for the starter). The lane keepers have a single pushbutton mounted in a Berocca container (painted gloss white, professional job here ;) ) and the starter has three buttons - start/stop/reset, prev and next (for selecting and starting the correct event).

The software on the EtherTen is basically a state machine, which retrieves event information (distance & stroke, which lanes are active, who's swimming, their personal best times and their handicap for this race) over TCP from a bespoke daemon which runs on my laptop and displays this information as a marquee on the DMDs. When the starter starts the race, the display becomes a stopwatch and as each swimmer finishes the race, their nett time and finishing position are displayed (along with an indicator showing if they've swum a PB time). The Arduino submits each swimmer's time and finishing position back to the daemon which records the times in our database, which gives us live online timing via our web site. I'm also in the process of implementing a change to tweet each swimmer's results in real time :)

If I'm not completely swamped with marshalling the kids (which is usually the case) on Sunday I'll see if I can remember to take a video or two of the board in action!

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Simon
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Re: EtherTen + 2xDMD = Swim Club timing board!

Post by Simon » Wed Jun 13, 2012 7:24 am

Managed to find a moment to grab a couple of videos of the timing board in action last Sunday.

The only problem is that the DMDs are so bright they oversaturate the CCD in my phone, so it's somewhat difficult to make out what's being displayed :lol:

Here's a couple of YouTube links for those interested :)

This one shows the board in "welcome" mode before the start of the first event, then the start.
http://www.youtube.com/watch?v=pIxlWAakBdw

This shows the finish of one of the races. As each swimmer touches the wall and the lanekeeper hits their button, their nett time (total minus handicap) is displayed on the board in finishing order, with an indicator next to their lane if they swam a personal best.
http://www.youtube.com/watch?v=wQOHBRXVebE

The lanekeepers doing their thing :)
http://www.youtube.com/watch?v=jV5pgPzhg1s

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Simon
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Re: EtherTen + 2xDMD = Swim Club timing board!

Post by Simon » Thu Jun 14, 2012 3:20 am

tronixstuff wrote:Wow - that's amazing. Thank you again for sharing that with us. Although I'm sure you spent a fair amount of time on it, would building it yourself been a lot cheaper than a commercial solution?
Certainly! Although I've not priced them, the commercial boards that I've seen are integrated with pretty awful meet-management software with its roots in the DOS era - I'd guess that the very simplest commercial option would be multiples of thousands of dollars. We're a very small swimming club, so there is absolutely no way we could have afforded anything near that.

The parts bill for my build came to about $250 out-of-pocket - I used lots of recycled materials which I had available to me (cabling, the enclosure, berocca containers :), power supplies). Even if I had bought all of that, the price tag would have been easily under $500.

As for the amount of time I spent on it, after purchasing the EtherTen and one DMD on the Sunday afternoon I had the idea, I had a working prototype up and running by Monday night and the first demonstration the following Sunday. Since then it's been an iterative spit-and-polish process, but the foundational work took maybe ten hours all up.

Granted I've already got the back-end infrastructure (database, web-app, etc) in place which has taken a lot of effort but the timing board itself has been a fast, cheap exercise thanks to the world of Arduino and Freetronics! 8)

swordfishBob
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Re: EtherTen + 2xDMD = Swim Club timing board!

Post by swordfishBob » Fri Jul 13, 2012 6:56 am

As a club technician and qualified starter and timekeeper, I say "Well done!"
You probably couldn't use it for a qualifying meet, but it'd be great for club meets, and also local school carnivals.

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Simon
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Re: EtherTen + 2xDMD = Swim Club timing board!

Post by Simon » Fri Jul 13, 2012 10:51 am

swordfishBob wrote:As a club technician and qualified starter and timekeeper, I say "Well done!"
You probably couldn't use it for a qualifying meet, but it'd be great for club meets, and also local school carnivals.
Hell no, the intention was never to build something suitable for qualifying-level competition, rather I wanted something to help our regular weekly encouragement meets to run more smoothly, with fewer errors and inaccuracies.

While it's definitely met that goal (and an itch got scratched in the process) by far the most rewarding outcome has been the reactions from the kids. Since I've added an indicator to the display for a personal-best result, it's been awesome watching the instant gratification the kids get when they see straight away that they've beaten their best time 8)

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