Re: Sensors and the input layer (was Re: [RFC] [PATCH V2 1/2] input: CMA3000 Accelerometer driver)
From: Pavel Machek <hidden>
Date: 2010-09-24 13:06:25
Also in:
linux-omap, lkml
From: Pavel Machek <hidden>
Date: 2010-09-24 13:06:25
Also in:
linux-omap, lkml
Hi!
quoted
So a voltmeter really makes no sense. It's not a set of keys and it doesn't give X/Y/Z style readings. Nor does a camera. But a lot of things do fit this to varying degrees. I'm actually more dubious than Linus about ALS - because ALS tends not produce 'events' but to be sampled, and there are significant power implications to unnecessary polling.
That's very similar to analog joysticks, no?
quoted
And the more it's used the less special code is needed in user or kernel space for PDAs and phones - instead they just work.OK, so let's say we start moving some of the devices into input. Which ones we consider suitable for input? I guess some 3-digit accelerometers, what else? Also, what new event types would we need? Let's take GPS - I do not think that ABS_X and ABS_Y are the best events to be used for such devices: I am trying to allow applications being
I'd not put GPS into input; yes, they do present 'x,y,z' in meters, but that's not what users want. 'lat,lon,alt' is better, but it is actually 'lat,lon,herror,alt,verror,time' and a lot of other metadata... Also, we already have driver for GPSes, its called gpsd. I'd leave GPSes out of input.
Also, GPS, liek ALS, would probably be polling, no?
Normally, GPS just sends you position info once a second. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html