Re: Barometric altimeter on 'future' Freerunner ?
I can see exotic applications for this but certainly not enough to put it into the phone. If you need it, add it via USB host, that's what we've got it for. (Same is true for the railgun. ;) ) Ortwin On 5/18/08, Stroller [EMAIL PROTECTED] wrote: On 17 May 2008, at 22:17, Philippe Guillebert wrote: Matthias Schulze wrote: I am wondering about applications possible with the Freerunner (connected via usb) or later phone models, if a barometric altimeter would be included. Hi, Err, doesn't GPS give us a pretty accurate altitude already ? lol. No. Event if the precision is something like +/- 20 meters, I believe it's got a better accuracy than a barometric altimeter that you've got to calibrate to the meteorological conditions all the time. GPS altitude precision is more like +/- 200 metres. Even cheap electronic altimeters are accurate to a few feet. That they need daily calibration makes them only of use to people who actually _need_ to know their height - an altimeter built into a digital watch, for instance, is usually no more than a gimmick, but a hang- glider pilot can simply hold down the zero button on his £100 altimeter for 3 seconds and then knows his height accurately for the duration of the day's flying. Stroller. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
Actually, implementing a railgun would probably be feasible as long as the projectile weight and powerload is taken into consideration. I'm not sure if the battery can handle multiple +1 gram projectiles though. And not to mention the need for a new chasis with space for a PCB with series of capasitors as I suspect the chemical battery can't deliver the necessary Ampere during the short time the projectile spends accelerating on the rails. ^_^ Would be cool in an extremely geekyness way. What's next, a freerunner chasis that doubles as a tesla coil? PS. Tesla coils are way cool, with a sufficent _high_ voltage it's even possible to use your body/hands/fingers as a tesla coil. Imagine using your body as a electric resonance cavity and then letting the lightning play between your fingers and your hands. Now add a mad scientist laugh while wearing a laboratory coat. ;) Completely OT? You bet I am! :P Heikki Soerum. PS. Go read about what Tesla did with electricity.. It will blow your mind. Den Sat, 17 May 2008 20:07:56 +0200 Daniel Selinger [EMAIL PROTECTED] skrev: On Sat, 17 May 2008 17:21:20 +0200 Erland Lewin [EMAIL PROTECTED] wrote: A 3 axis magnetometer (compass) would also be a cool thing to have on the phone. I vote for a railgun ^^ sry : ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
On 17 May 2008, at 22:17, Philippe Guillebert wrote: Matthias Schulze wrote: I am wondering about applications possible with the Freerunner (connected via usb) or later phone models, if a barometric altimeter would be included. Hi, Err, doesn't GPS give us a pretty accurate altitude already ? lol. No. Event if the precision is something like +/- 20 meters, I believe it's got a better accuracy than a barometric altimeter that you've got to calibrate to the meteorological conditions all the time. GPS altitude precision is more like +/- 200 metres. Even cheap electronic altimeters are accurate to a few feet. That they need daily calibration makes them only of use to people who actually _need_ to know their height - an altimeter built into a digital watch, for instance, is usually no more than a gimmick, but a hang- glider pilot can simply hold down the zero button on his £100 altimeter for 3 seconds and then knows his height accurately for the duration of the day's flying. Stroller. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
On Sunday 18 May 2008, [EMAIL PROTECTED] wrote: GPS does give relatively accurate altitude/speed but it does have error and is nowhere near as accurate as a calibrate barometer (since an aircraft altimeter is just a barometer with a different face). Assuming someone has a data plan you can get the barometric pressure from a nearby airport (most have a weather station, all data is pooled by the FAA online**). Wouldn't be sure about other countries but I bet France/most sizable would have something similar. That or you could assume the standard 29.92 in/Hg and 1000ft per 1 in/Hg. An even more desperate thing you could do is call 1800-WX-BRIEF and ask what the baro is at a local airport. **They also maintain a very detailed list of all airports available as an XLS file. The airport information is available globally, and used by the kweather panel applet. It looks like policy may vary by country for the size of airport to be listed, but generally speaking it'll be listed if it handles international flights. kweather lists temperature, air pressure, wind speed and direction, sunrise and sunset, dewp oint and relative humidity. I haven't looked to see if anything else is published, or what the update interval is. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
On Sun, 2008-05-18 at 11:58 +0100, Al Johnson wrote: On Sunday 18 May 2008, [EMAIL PROTECTED] wrote: GPS does give relatively accurate altitude/speed but it does have error and is nowhere near as accurate as a calibrate barometer (since an aircraft altimeter is just a barometer with a different face). Assuming someone has a data plan you can get the barometric pressure from a nearby airport (most have a weather station, all data is pooled by the FAA online**). Wouldn't be sure about other countries but I bet France/most sizable would have something similar. That or you could assume the standard 29.92 in/Hg and 1000ft per 1 in/Hg. An even more desperate thing you could do is call 1800-WX-BRIEF and ask what the baro is at a local airport. **They also maintain a very detailed list of all airports available as an XLS file. The airport information is available globally, and used by the kweather panel applet. It looks like policy may vary by country for the size of airport to be listed, but generally speaking it'll be listed if it handles international flights. kweather lists temperature, air pressure, wind speed and direction, sunrise and sunset, dewp oint and relative humidity. I haven't looked to see if anything else is published, or what the update interval is. Its based on METAR information (http://en.wikipedia.org/wiki/METAR) - basicly text based codes. A typical METAR report contains data for the temperature, dew point, wind speed and direction, precipitation, cloud cover and heights, visibility, and barometric pressure. A METAR report may also contain information on precipitation amounts, lightning, and other information that would be of interest to pilots or meteorologists such as Colour States Just retrieve and process using perl or a lesser language. BillK ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Barometric altimeter on 'future' Freerunner ?
Hi, I am wondering about applications possible with the Freerunner (connected via usb) or later phone models, if a barometric altimeter would be included. A potential barometric device might be this one. http://www.intersema.com/site/technical/ms5534.php (which seems to have a usb-version) At the start of an outdoor trip actual barometric pressure altitude could be referenced to gps detected altitude. Given stable barometric pressure (i.e. no wheather change) this reference should hold independently of altitude. Upcoming low pressure areas bringing bad weather might be detected in case a certain tolerance given to the inital reference is no longer met. Other uses might be personal wheather forecast or sending gps-position tagged atmospheric pressure data to a central wheather server and so on. Well, just an idea, Matthias ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
2008/5/17 Matthias Schulze [EMAIL PROTECTED]: I am wondering about applications possible with the Freerunner (connected via usb) or later phone models, if a barometric altimeter would be included. I like the idea. I was looking at Suunto watches a while back, and I think they had some way of handling whether to interpret air pressure changes as weather change or altitude change. Of course, with a GPS accellerometers, we can probably tell if the phone is moving or not. A 3 axis magnetometer (compass) would also be a cool thing to have on the phone. /Erland ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
On Sat, 17 May 2008 17:21:20 +0200 Erland Lewin [EMAIL PROTECTED] wrote: A 3 axis magnetometer (compass) would also be a cool thing to have on the phone. I vote for a railgun ^^ sry : ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Barometric altimeter on 'future' Freerunner ?
Matthias Schulze wrote: I am wondering about applications possible with the Freerunner (connected via usb) or later phone models, if a barometric altimeter would be included. Hi, Err, doesn't GPS give us a pretty accurate altitude already ? Event if the precision is something like +/- 20 meters, I believe it's got a better accuracy than a barometric altimeter that you've got to calibrate to the meteorological conditions all the time. thinking about the altimeter, since the standard geoid is pretty approximate (yeah, our good old Earth is more like a potato than an eliipsoid) : it would be good to have a way to set an offset parameter between what's the gps tells you and what altitude is shown ; this way, you can compensate this kind of errors by calibrating against a geologically surveyed point (measured by the IGN in France, USGS in the US...) My 2 cents -- Phyce ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
