How much memory needed? And what about lateral g's?

Hothatch

Hi there,

I finally bought a used S60 mobile and can't wait to try out this fine piece of software, which you so kindly created for us track day enthusiasts. Thanks so much for that!

Now, since my phone will not arrive until tomorrow or monday, I was wondering if I will need a bigger memory card than the 64MB one that comes with it? How much space will, say, a session of around 8 to 10 laps approximately need?

Also, as far as I can see, RaceChrono currently doesn't put out lateral g's. Is this a feature planned for future versions? That would be an awesome feature to have.

Regards,

Hothatch

aol_of_RaceChrono

If you don't disable NMEA data, then 64 MB might be too little. Bigger cards are very cheap, so do get one. Rule of thumb would be around 10 MB per hour.

There haven't been that much requests for lateral G-forces display, but I might consider them if I find a good way to implement them user-interface-wise.

Hothatch

Thanks for the info. I'll get a bigger card then. Is there anything to consider when getting an mmc? Like read/write speeds, or are they all the same?

And while I personnally think lateral g-forces would be very cool (especially with the possibility to export .vbo data and analyze it), I do understand that it will be more important to implement features which are in higher demand. So, just keep what you are doing, it's great!

aol_of_RaceChrono

It might be easily doable for export, as no user interface needed. Also some video overlay software might benefit from this.

Not sure about the memory cards, I usually buy what ever is cheapest. Just buy the correct type of card, the latest Nokia phones use MicroSD-cards. Bit older might use MiniSD or MMC of some sort.

Hothatch

Thanks again. I bought a Nokia 6670, so it's MMC for me. And those things are indeed a lot cheaper than I thought.

Personally, I'd only need g-forces for exporting. User interface is really not important for me. In any case, I'm really looking forward to trying out RaceChrono, be it with or without lateral g's.

jason

The lateral g's would be great. What about measuring height? I would imagine the gps' would be able to work out height. Would the accelerometer in some phones like my N82 not be able to measure the lateral g's if the phone was mounted a certain way?

anibarro

lateral forces can be calculated from path, speed and time, you don't need an accelerometer, so you don't have to worry

jason

And lean angle? I am using it on a motorcycle so maybe a way to show you what lean angle you are using around certain turns. This would allow you to work on lines.

Hothatch

I'm not very technically minded, but I reckon, lean angle will most certainly be impossible to calculate from GPS. Even if you could work it out from positional data, the accuracy of that data is limited to metres. Way too much to pick up the subtle differences that could give you an indication of the lean angle.

@jason: Any GPS receiver does put out height per default anyway, it's usually just not very accurate. I don't know how big the margin of error usually is, though. Might not be much worse than xy-data.

aol_of_RaceChrono

True, the lean angle can't be determined with just the GPS.

jason

Cool thanx Hothatch & aol!

@ Aol - Well done and thanx for all your effort on this great app!