Logging Bluetooth Accelerometer Data on a PDA? 24
sessha asks: "I want to log data from a Bluetooth Accelerometer (actually 5) attached to different parts of the body. How one would go about logging the data onto a bluetooth compatible PDA. I know quite little about PDA OS's, but the main concern is functionality - it doesn't matter if it is PalmOS or Windows CE or whatever. The Linux and Windows directions for data logging are shown, but how would one best go about this on a PDA? Also, it would require at least 256 MB storage, preferably more, since this will be recording 300 of these ASCII strings a second for a number of days. Suggestions as to the best equipment and software to use for such an endeavor would be greatly appreciated."
Simple math (Score:4, Informative)
16*300*60*60*24 = 414720000 bytes/day or about 400megs / day
If instead you use a simple binary representation with 6bytes/record we get
6*300*60*60*24 = 155520000 byets/day or about 150megs / day
I bet the data would compress really well, but if a pda would have enough horspower to log and compress is an open question, I would guess yes.
ps
If you want to play with bits and save 2 more bits per record then we get:
5.75*300*60*60*24 = 149040000 bytes/day
Re:Simple math (Score:2)
its 14 bytes / string (including newline)
so the first number should be 362880000 bytes / day
Battery Life (Score:4, Informative)
Given that WinCE based devices are generally known for shorter battery lives, I'm not so sure that your request is practical with current technology.
Now, what about an Ipod-style device? They have big hard disks, and they're designed to run for many hours. That's where I'd be looking - either that or those new-fangled 'wearable computer' things that have a hard disk and a bluetooth adaptor and can be thrown in your bag to allow you to access your personal storage at any computer.
Re:Battery Life (Score:3, Interesting)
WinCE would be the easiest thing to do this in. I've done a lot of PDA programming, and I'd take WinCE an
uh, google? (Score:2)
and you could as added bonus check if that linux software would work with zaurus+bt(in sd or whatever, can't remember if the newer one's ship with included bt).
some big cf card to that and you're ready to go.
though, remember the energy usage of such devices in continuous operation...
cheap solution: sharp zaurus 5500 (Score:2, Informative)
put a big CF storage card in it, and use any one of the various bluetooth hacking/logging tools to put all received packets into an onboard mySQL database, or just prune some
really an easy project, and cheap.
Re:cheap solution: sharp zaurus 5500 (Score:3, Insightful)
Pity it only has a battery life of an hour or so when playing MP3s according to the Unofficial Zaurus FAQ. I guess you might get another hour if logging strings, especially if your app is designed to do it without too much load on the system.
Re:cheap solution: sharp zaurus 5500 (Score:2, Informative)
Re:cheap solution: sharp zaurus 5500 (Score:2)
hahaha! good one!
Not even my SL-C760 gets that battery life, and it has a battery that's twice as big.
That said, the SL-5500 might be OK if you could get bluetooth to work. Judging by what I hear in #zaurus on freenode, a lot of folks can't get it working. And these folks are Linux nerds, not PalmOS converts who expect the Zaurus to "just work" like a Palm or PocketPC would.
Re:cheap solution: sharp zaurus 5500 (Score:2)
Re:cheap solution: sharp zaurus 5500 (Score:1)
Me too. I ssh to mine in the morning, often forgetting to plug it in, and am still using it by the end of the day. Anyone who 'only gets an hour or so' out of their 5500 either has a bad battery, or isn't managing it right
Try zaurus (Score:2)
Windows Mobile 2003 SDKs... (Score:1, Informative)
Windows Mobile downloads [microsoft.com] - start here.
In particular, the Windows Mobile 2003 SDK [microsoft.com] will be of interest, as will the eMbedded Visual C++ IDE & compiler [microsoft.com] (don't forget service pack 3 for it [microsoft.com]).
There are a dizzying array of other tools and SDKs available from that site, so take some time to read everything. There's also a PocketPC emulator for Windows (not sure if that's included in the eMbedded V
What might kill the deal... (Score:5, Interesting)
This is really a job for an embedded computer engineer. If there's money, safety or reputation at stake, I urge you to find one to help you.
Re:What might kill the deal... (Score:2)
Whoa!! Where can I get some of these!? (Score:3, Insightful)
I've been looking for something like this for a loooong time! The closest I've seen are serial devices in the $500+ range. These would be perfect for a number of applications I've envisioned.
Re:Whoa!! Where can I get some of these!? (Score:2)
Re:Whoa!! Where can I get some of these!? (Score:2)
I'm most familiar with the DIY headphone amp scene, but from that limited experience, I would expect that someone interested in these would be taking orders so as to get the volume up in order to reduce pcb printing and part costs even if there is still some DIY involved.
Simputer (Score:4, Interesting)
Compress that data (Score:2, Insightful)
Telling the difference between streams (Score:1)
I guess different devices might get different starting sequence numbers - if that sequence number changed on evry packet won't take long to loop and make a mess of things...