Sorry to post in English, my Korean is not very good.
The main results of my test are here: http://bit.ly/cBM9od
I read a few posts about the "compass" in the Motoroi not working; first, there is no "compass" in the Motoroi per se, there is
magnetometer which is used by software to generate headings. A magnetometer and a compass are very different;
magnetometers are VERY sensitive to metal and this can greatly effect your "compass" readings.
You can download Metal Detector (http://www.androlib.com/android.application.com-imkurt-metaldetector-qEE.aspx)
from the Android Market to see how sensitive the magnetometer is in the XT720 and here is a link of it working on a HTC G1:
http://www.youtube.com/watch?v=MzSJKpsNUFo ).
Also, there is a difference between: True North and Magnetic North
A compass will try to verify Magnetic North and maps are usually drawn using True North, therefore using a map and compass you will
often find differences for the direction of "North" which you need to compensate for using the Magnetic Declination.
My results show that, at least for me, there is no problem with the magnetometer in XT720.
아담
in my opinion, the problem is not only magenetic sensor but also orientation sensor. so, google skymap doesn't work well.
it maybe program's bug that can't calculate proper.
맞나요?? 짧은 영어로 일단 썻는데.. 문제는 오리엔테이션 센서와 지자기 센서의 수치를 계산하는데 오류가 있다는 겁니다.
x,y,z 축 계산이 폰이 누워 있을 때는 잘 될 지 몰라도 세우면 무조건 서쪽만 보게 되죠.
yes it's true that the motoroi uses a magnetometer to differentiate north/south/east/west, but how can you explain the fact that droid phones DO NOT have any problems when running google skymap? does this mean that droid phones use real compasses to find direction? or maybe it's simply because DROID DOES... jk :P
@파드메아미달라
I tried a few 3d compass apps from the Android Market, they seemed to work fine for me. Layar also worked but it is a bit
buggy and forces closes on me a lot, but I understand they have a new version out so I will try again using that version.
The just released version of SkyMap worked correctly ONCE, right after I updated the application, after that first time
it gave incorrect heading information. I think that SkyMap is buggy on the XT720 (see below for more information)
@흰앙큼호두과자
Currently, I would have to agree with you. But I think more testing is required to actually confirm this.
@조쉬
Once possible reason is that the magnetometer used in the Droid is different than the once used in the XT720. I now believe that
the XT720 is using AK8973 sensor. This is manufactured by AKM Semiconductor and they market it as a 3-axis compass
(datasheet: http://www.datasheetdir.com/AK8973+download ) not as a megnetometer, which I find interesting. I will has to
read the datasheet to see exactly why they are using "compass" instead of "magnetometer".
Additionally, I have fouind some interesting articles on testing the sensors used iin Android phones
(http://mylifewithandroid.blogspot.com/2010/03/sensors.html ). I will test soon and share my results again.
Another possible reason is could be the use of a lot of metal in the XT720 phone, which can give rise to heading errors when
a magnetometer is being used; the Droid, I believe, has an entirely plastic case so it would not be prone to these errors.
Finally, it could also be a software problem with SkyMap or even the AK8973 sensor. One user posted that the SkyMap objects
were off by 15 degrees on his Nexus One (which also uses the AK8973 sensor); Google's response:
"Hi. My name is Kevin and I'm from the Google Sky Map team.
You can read the full thread here: http://www.androidpub.com/?mid=phone_motoroi&page=2&document_srl=287717 so it is entirely possible
that the software is not working as intended on the XT720.
Finally, I am Motorola Development member, I will post to the MotoDev site and see if I can get some answers from their technical product
engineering tream.
즐거운 주말!^^
아담
I'm afraid.... it occurs when you hold your xt720 perpedicular to the ground. :(
2-dimensional app works well enough, but try google sky map or 3d marine compass, layar.... ㅠㅠ
(droid is free from the issue under same condition)