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Barometer is very cool addition. I'm sure they'll eventually have an API for it.
by bhartzer 12y ago
Barometer is very cool addition. I'm sure they'll eventually have an API for it.
- dominotw 12y agoWhat is it used for in the phone?
- krallja 12y agoRelative elevation tracking.
- tonyhb 12y agoIt means instead of waiting for a GPS lock in 30 seconds it's under 10. The barometer makes calculating your position via GPS much quicker, as it has an additional piece of data to simplify some of the maths it does. Edit: here's a source which may confirm - http://pocketnow.com/android/google-confirms-barometer-intent-faster-gps-locks http://pocketnow.com/android/google-confirms-barometer-inten...
- DigitalJack 12y agoYeah, that doesn't make any sense. Barometers are only good for detecting relative altitude/elevation changes over short periods of time. Over longer periods of time (hours/days) the atmosphere pressure is going to change whether you change altitude or not. Over short periods, the barometer can give a relative change. Without a known starting point, it can't give you absolute altitude/elevation. It has nothing to do with getting a gps lock. I'd be pretty surprised if the phones didn't pull down the satellite constellation data over the network vs waiting on the nav message broadcast from the satellites.
- liviu 12y agoI think the elevation changes over short periods of time are essentials for the fitness apps.
- mikeash 12y agoAny decent smartphone can already get a GPS fix in a second or so. The main bottleneck to a GPS fix these days is simply downloading the satellite positions. This is done over a 1970s-era protocol that operates at 50bps and takes about 30 seconds to transmit all of the data. Smartphones bypass this by downloading the positions over their local data connection, which cuts that down to a fraction of a second. Fixing your altitude to +/- 2000ft doesn't really help the process to any significant degree. If you have the satellite positions or can get them quickly, the rest comes fast. If you don't, you're doomed to be slow.
- tonyhb 12y agoHuh, interesting. That's pretty cool to know. Thanks!
- jonifico 12y agoHow much elevation are we talking about? Will it detect if I crouch and stand up, or you mean more geo-based elevation?
- rzt 12y agoElevation for fitness apps and environmental and weather(?) reporting.
- danbruc 12y agoBarometers are often used to improve motion tracking accuracy, not sure if this is a common use case for phones.
- stusmall 12y agoHow is that helpful in motion tracking?
- danbruc 12y agoWith sensor fusion you can improve the accuracy over just using GPS and accelerometers; it is quite common in quadcopters.
- RyJones 12y agoaltitude is usually the least accurate position given by a GPS. A barometer helps you get closer, faster.
- was_hellbanned 12y agoI have some MPX5100 pressure sensors connected up to an Arduino. When I first experimented with them, I was shocked to find that they were accurate enough to report pressure change simply from lifting the device off my desk and up to eye level. Not that this says anything about the sensor used in the iPhone, but it's not unreasonable to expect that it could be used as some form of motion input.
- trhway 12y agomay be i'm too introvert or just don't have the imagination - i'd more understand adding more sensors toward "tricorder", ie. ones that can say more about condition/health of the human host of the phone (temperature, heartbeat, alpha/beta/theta-waves, dopamine level, etc...)