I've rewritten it in C
Result is 50% CPU load (25% my application, 25% pulseaudio) while CPU is at 250 Mhz (the lower bound).
Python variant consumes 60% CPU (40% my application and 13% pulseaudio) while CPU is at 500 Mhz.
So reimplementing in C give significant performance advantages.

Now it is time for making GUI.

GUI is out. I hadn't opportunity to test it on a bike, but it should work.
http://kibergus.su/node/46

By the way, is anybody interested in it or am I the only idiot, who wants to use $700 phone instead of $20 device?

No, you're not the only one -- I just got some gear in this past week, so I may start experimenting soon.


My setup so far:

• Phone holder bracket (http://www.dealextreme.com/details.dx/sku.15544)
  Seems to work OK, though I don't know how long it'll last. If it breaks too soon, there's always the B&M, or even something custom.
  
  (BTW, anyone notice the N810 had audio, charger, and USB all three on one end, begging for homebrew docks, but now that the N900 has only two, they must be on opposite ends?)
• Speakers (http://www.dealextreme.com/details.dx/sku.28655)
  Loads of empty space inside, so I'm thinking this will be the hub for all glue circuitry. Not sure about weatherproofness of speakers, though...
• Battery pack -- for now, an Energizer XP18000, with 5V/1A it's fine now, but the higher voltage outputs are a little oddball and/or weak for when I integrate my lights.

Naturally, important things first, so I took it on a 37-mile cruise yesterday to check out the music-cranking (top priority) and physical reliability (xecond priority); building the speedo rig comes later.


So I gotta wire up a permanent power setup, with a tap from the speaker to the N900, and a 4-pole cable from the N900 to the speakers, then run the reed switch down to the wheel. May not happen until next weekend, but I am getting there...


FWIW, I'm not especially interested in the speed, as I find the GPS speed reading good enough. What I want is reliable odometry, that doesn't add up random GPS drift/jitter while I'm parked, doesn't skip or reset when I lose GPS in a tunnel, etc. A less-ticklish speed readout is cool, but not enough to get me excited -- I think that may be why you're not seeing more interest.

As for the addons you mention, a couple thoughts:

Slope detection with accelerometer -- maybe the roads around here are just horrible, and it would be fine where you are, but I can't see this working well at all. IMO, though, integration of GPS would be great -- plot altitude every 20m or so, plot altitude/slope history from that. (GPSjinni does similar using GPS only, but it does speed vs. time and altitude vs. time -- I want x vs. distance.)

Anyway, I'm sure I'll have more thoughts, and maybe a few patches, once my hardware comes together. Still hoping for some OTG/webcam goodness -- I'd kill to see your speedo display overlaid on a live rearview cam!

Any news? .

I had some other things to do. So no visible progress yet. only ideas how interface should look like (I want to have ability to easily add and delete distance/speed counters on the go), what classes do I have to write and what QT classes are needed to implement this. No code yet.
P.S. But I've rebuilt it for QT 4.7 which is now in repositories.

My use case is the same as Benson's, but I haven't got my hardware set up yet.

Please don't make whatever ends up in the repos depend on 4.7. Who knows when it will be stable+officially supported on N900.

4.6 was removed from extras-devel and not supported any more. 4.7 is now in extras-devel. I already use QML which is present only in 4.7. But you shouldn't worry, 4.7 does not conflict with current stable version and can be installed simultaneously.

Actually, one of the reasons for writing this application was to take a look at QML.

I use eCoach application for cycling, running, walking etc...

http://maemo.org/downloads/product/Maemo5/ecoach/

What? That doesn't make any kind of sense at all. 4.6 is the base Qt lib version now on the device. How could it even be possible for it to not be available?

Anyway you're obviously free to do with it as you want. Actually, the navit gui developer is doing the same thing with QML, but the dependence on 4.7 of his packages is a hindrance to that app's adoption by end users.

To me the idea of this program I like.

Within six months, when I recover from the accident, I would like to have to try.