Poor Sensor Fusion in Lumia 900

[dotMorten]

I've been working a lot in the Augmented Reality space, and was very excited for AR when the Lumia 900 shipped with a Gyro - Finally a full-motion sensor windows phone that sells in large numbers.
However, I've found that the sensor fusion algorithm that the Lumia phone applies is horrible at best. It basically doesn't take proper advantage of the gyro.
The sensor fusion is a mix of 3 sensors:
Accelerometer, Compass and Gyro. 1st generation windows phones didn't come with a gyro, and made the AR experience really poor.
The purpose of the Gyro is two things:
1. Reduce the noise coming from the accelerometer
2. Detect fast rotational changes (to compensate for the compass which is slow to update).

#1 works fine on the Lumia 900, and I don't see a lot of noise. However, #2 is almost non-existent, and the gyro get way too little weight on a fast rotation. This gives a really poor user-experience when doing augmented reality apps (including Nokia's own City Lens app) because any movement shows huge lag when rotating, and it makes it almost impossible to play fast-paced games based on AR.

To demonstrate what I mean, I have recorded a video that compares an HTC Titan to a Lumia 900. I've been able to reproduce this on several Lumia's, and I haven't seen a single other phone with a gyro that has so poor responsiveness. http://www.youtube.com/watch?v=_lEIpkBT4r4


The HTC phone is on the left, and Lumia 900 on the right. Notice that when the phone is tilted fast, the labels on the screen instantly moves on the HTC, but on the Lumia they slowly move towards the right position.
You should be able to reproduce this with any augmented reality app, for instance the AR view in my GuidePost app:

I believe the Lumia fusion sensor firmware is due for an update...

[chintandave_er]

did you try diagnostic tools to get more details on sensor reading?

To access the tools in Lumia, simply enter "##634#" on the call screen and it'll load up. There you can see all sensors test including Gyroscope.

[hamishwillee]

did you try diagnostic tools to get more details on sensor reading?

To access the tools in Lumia, simply enter "##634#" on the call screen and it'll load up. There you can see all sensors test including Gyroscope.

Where are these documented? Would it be a good idea to create a wiki topic (categories Windows Phone, Debugging, Testing) that include this information, information about the tests covered, and links to related topics on MSDN?

[chintandave_er]

Hi Hamish,

I did some RnD on that and found that it is not documented in MSDN as dial number is varies with mobile company (Nokia, Samsung, HTC etc.). But I found specific for Nokia on some blog.

Yet it is not well documented and have news kind of format rather then wiki article. Find those below.

http://www.wpcentral.com/nokia-lumia...s-get-detailed

Check out: Video Demo
http://www.youtube.com/watch?feature...&v=XxjiXO4nvnk


Yes. It would be good idea to add wiki article on this topic. I will try to make article on Diagnostic tools this month

[joaocardoso]

I'm wondering if this is a problem with the responsiveness of the sensors, the algorithm or the GPU. Or a combination of all. Thats a huge performance difference.

[hamishwillee]

Yes. It would be good idea to add wiki article on this topic. I will try to make article on Diagnostic tools this month

Thanks Chintan. I've kicked it off here. Its probably sufficient, but if anyone can work out how to get images that would be great - didn't want to copy those on blog because we don't own them.

[chintandave_er]

Thanks Chintan. I've kicked it off here. Its probably sufficient, but if anyone can work out how to get images that would be great - didn't want to copy those on blog because we don't own them.

Thanks Hamish. I will improve it further.

Also I will provide screenshot of all various tests available there in Diagnostic tool.
To take screenshot in Windows Phone, I need to make it developer device by unlock it for development using code provided by App Hub (Windows Phone marketplace) account.

And I have one. So I will first unlock it by this and take screenshot. Also Will lookout on marketplace if there is any app for screenshot like Symbian (but I think NOT)

Chintan.

[hamishwillee]

Thanks Chintan. I don't think unlocking the app will help, or that there is a screenshot app - although I could be wrong. My understanding is that it is only possible on WP to capture the screen of an app from within the app code itself.

[ltomuta]

Chintan is right, it is possible to take screenshots. But this is getting off topic
The diagnostic tool would show anyhow just that the sensor is working, but I don't expect it to be useful for measuring its raw performance or that of the fusion algorithm.

[chintandave_er]

Right Lucian. sorry for going out of topic.
@Hamish: It is possible now. we can do that using "screen capture" app but it is not avaialbe in marketplace. so need to install manually and for that we need to unlock WP device to allow such dev. apps. (can be a wiki article too )

check out below articles which has demo video too.
http://www.redmondpie.com/take-scree...n-capturer-v2/
http://www.peterskitchen.net/?p=6596

FYI, You can do many thing out of the box after unlocking wp like Windows Phone hacker showing on below link. (interesting one). But MS not allowing this officially over marketplace.
http://windowsphonehacker.com/articl...lease-03-28-12

[hamishwillee]

R. (can be a wiki article too

Thanks guys, Chintan, please create this on wiki - it was news to me!

[chintandave_er]

Thanks guys, Chintan, please create this on wiki - it was news to me!

sure.. I will soon.