Thursday, June 16, 2011

Arduino Wireless F3F Timing System ready for F3F Swiss Cup

In the last few months, my F3F activities were quite busy! International Open and Open German Championship in Rügen, Eurotours in La Muela and Poland, attempt at Swiss Cup in central Switzerland (no wind), attempt at French League in Grenoble (no wind), French Championship last weekend, there were plenty of days roaming slopes here and there in Europe. Preparing for those contests took some time too. So I didn't have much evenings tweaking the timing system developed this winter.
But now, after a few more evenings sitting between wire salad, soldering iron, drill, screwdriver, and netbook, I am quite proud to announce the birth of what I used to call the "Arduino Wireless F3F Timing System"!
Since it is my child, of course it looks nice, but it also has some brain(s)! And, most important of all, after much indoor debugging and testing, I would say it works!
I would lie to you and myself if I wouldn't admit that there still could be some tweaking and optimizing in the codes here and there. There is even a whole bunch of configuration options still to implement to run a non FAI standard contest with it. But for now, for the upcoming F3F Swiss Cup I organize this Sunday, it shall do well enough.
So what changed since the last report here?

Arduino Wireless F3F Timing System
First of all and most important, after discussions with CDs, pilots, and colleagues here and there, I abandoned the idea of having a single button on the bases handles. I added a rugged red "small button" on each grip. On base A, it acts first when the glider leaves base A ("on course"), and after this event as the security line breach button. On the base B handle, the small button is solely for security line breaches. The small button is conveniently located at the opposite end of the grip, so it can easily be pushed by the left hand thumb. So now, the main large button is used exclusively for base crossing during the run.
In the base handle behavior, the pushbutton delays in the code have been replaced with timestamps. So now the grip recognizes each specific signal when simultaneously pressing main and small buttons. This is utterly important when the glider returns immediately into the run after leaving base A.
I feel I am right interpreting the FAI rules: each time the security line is crossed, the pilot gets 100 points penalty. For two security breaches, -200 pts. For three, -300 pts, etc.
The wireless sound system integrated in a case with a small car amplifier and connected to a 40W horn loudspeaker is fully functional. Round number and pilot number are announced once selected by the CD before each run. Thirty seconds countdowns are spoken out automatically and stopped whenever the next event occurs: "30...20...10...5...4...3...2...1". Run results and penalties are spelled out as well after the run. They are simultaneously displayed on the bright and large 3 digit 7-segment led display also running wireless. The 5-second antidiving countdown is displayed as well.
The wireless wind station was certainly the most difficult part of the system. It features a tilt compensated compass fixed under a quite sensible, but stable sailing windvane. It also integrates a normal reed switch anemometer for wind speed. Measurements of both devices are processed at a 5 Hz frequency and the computer continuously computes running averages for wind deflection and speed. The device send four different signals to the CD device: instant wind ok, instant wind ko, 20 second wind ok, or 20 second wind ko. This is enough for the CD and its CD device to know if the conditions are good or not before and during a flight! If the wind is ok during the run, its average speed and deflection are stored together with the laps and run times on the SD card. If the wind is bad during the run, we go into reflight which can occur immediately, or at a later time during the round. No judge needed anymore to concentrate all day long on small digits on a handheld anemometer or on the arrow of an analog display. No need to start a handheld chronometer every time the wind goes below 3 m/s. The wireless wind device does it automatically and sends appropriate alarms (positive or negative) to the CD device for further processing.
Well, I could tell so much more about details and functions. For now, it is time for this timing system to go into the field testing phase. But there are already some nice add-ons I think about to implement in near future. For now, voice announcements are in English and stored on a SD card in the sound system. As soon as I have some time, I'll record all voice sounds in French, German, and Italian and store them on the SD card in separate folders. I will add a row in the pilots file specifying the pilot language. And I will adapt the code so that voice announcements will be spoken out automatically in the specific language of each pilot!
As many know, Switzerland doesn't hold together because of language unison. As well, my timing system modules will not fall apart if it suddenly can speak more than one language!!!


  1. Hi
    Do you have a F3 B system in mind.

  2. Hi acb,
    With so much F3F in mind, I would hardly find free RAM for F3B...
    But as soon as the code and part list is published, it could be a nobrainer for some dedicated programmer to adapt it to some other flying tasks.

  3. Ok, the system looks great
    Thanks and good luck