Idea: room measuring
 

hi, using the infrared port anyone can create an application for measuring a room.
The apps must to sell a IR signal and then start a timer...the signal bounce on the wall and return to the IrDA...the application can stop the timer and using the timer we can calculate the distance between the wall and the phone!

Re: Idea: room measuring
 

i am pretty sure there is only a transmitter of Ir signals, we cannot return them back. So, NO

Re: Idea: room measuring
 

The Ir is only transmit but I believe the camera can detect the frequency it emits, albeit at too low a refresh rate to do standard send and receive so the beam would need to be emitted for long enough for the camera to detect it.
Does that help?

Re: Idea: room measuring
 

There is an application for measuring smaller things, Metre.

I don't know is it any good in measuring something as large as walls, but it's pretty accurate with small things (+-1mm).

Re: Idea: room measuring
 

Combine with N900Fly, just throw your N900 across the room, and when it hits the wall you should have your measurement! ;) :D

Re: Idea: room measuring
 

maybe enough information from camera focus to measure distance??

Re: Idea: room measuring
 

This did not work as it recorded the bounce movement as well, damn you!!!

PS. is there a re-assembly thread?



;)

Re: Idea: room measuring
 

+1. Seems the most sensiible idea. Could go something like this: Open camera lens cover, quit out of the camera, start the measuring app, hold the N900 with the screen flat against one wall and then press the shutter button. Then the measurement is displayed on-screen.

May even be possible to make the app work out the area after a second reading is taken.

Re: Idea: room measuring
 

The new camera-ui now part of the CSSU gives a focus distance readout. However, it is not always clear what is being focussed upon, depending on scene of course.

Re: Idea: room measuring
 

I don't think the focussing information is going to be that accurate, and it would need a wall with a high contrast part to focus on - a plain wall just will not work.

Re: Idea: room measuring
 

IR-light moves with a speed of 299792.458 kilometers each second so you really need to speed up the N900 too ;)
But if it is a silent room then maybe a soundpulse and a measurement of the reflected echoes could guve a much more accurate reading, since sound only travels 340 meter on a second.

Re: Idea: room measuring
 

Re: Idea: room measuring
 

I've thought about using the lense focus length to measure stuff - it's extremely simple math (rudimentary geometry and algebra) to calculate it from there.

But at least using the Camera UI replacement included in CSSU, I have not seen the measurements to be too reliable... I've pointed it at a wall and focused, then mesures the actual distance from camera to wall, and there's definitely almost always some discrepancy. Though the Metre App linked to earlier seems to have implemented what I'm talking about already, and decently well. *Shrug*

Re: Idea: room measuring
 

Proximity sensor?
It really needs to be something that gives off a single point beam rather than an arc to avoid other items in the vecinity, like items of furniture etc.

Re: Idea: room measuring
 

Re: Idea: room measuring
 

One mentioned the speed of the IR light and the speed of the N900.

Beside that the camera "can see" the IR blinking of a remote control in visible light (I do not know why this is the case). Just try to make
a photo of a remote control's IR transmitter in action.

So you could mount a mirror at the wall and measure the time
N900 IR -> mirror -> N900 camera.
The problem will be the focusing on the tiny blinking dot and the
speed to measure. :D

Re: Idea: room measuring
 

bluetooth headset mic + phone speakers let you measure the distance between headset and phone.

It works with a wired mic too, but then it's easyer to measure the length of the wire.

Re: Idea: room measuring
 

You have the time of 4 processors clocks per meter of what you want to measure. Hope you are a good coder, because the linux kernel isn't real time ;)

Re: Idea: room measuring
 

good idea.......

Re: Idea: room measuring
 

Out of curiosity... Even if you were to make the IRnode register distances as great as a room, how would you be able to ensure that your line/beam is level without the internal compass?

Re: Idea: room measuring
 

Quick reply...
Accelerometer, simple!.. East or west, south or north, is quite irrelevant. However, IR transmitter is hardly sending a thin focused beam, just like accelerometer isn't perfectly accurate, so actual implementation is not going to be precise.
Best wishes.
__________________
Per aspera ad astra...

Re: Idea: room measuring
 

The 900 cant measure distances without any hardware added.

However, it could be possible to measure the sound in a room , and try to isolate all the roomnodes with FFT , and thereby get all the measurements.

http://www.sengpielaudio.com/calculator-roommodes.htm