Asahi Kasei will Provide Magnetometer (Digital Compass) for Apple’s New iPhone?
Posted by iPhoneHacks on May 21, 2009 | Comments (8)
Couple of weeks back folks at BGR had discovered debugging menus in iPhone OS 3.0 which indicated that Apple's new iPhone could come with a built-in magnetometer (digital compass).
AppleInsider is now claiming that Japanese manufacturer Asahi Kasei will be providing the magnetometer (digital compass) for Apple's new iPhone.
People familiar with betas of the iPhone 3.0 software developers kit
recently dug up several header files attributed to the Japanese
manufacturer in a directory appropriately labeled "compass." More
specifically, the files identify Asahi Kasei's azimuth sensor No.
AK8973, a 16-pin leadless IC package measuring 4mm square and 0.7mm
thick, as the chip that will help future iPhone users determine their
direction. It bundles a master clock oscillator.
We have seen the magnetometer used in T-Mobile's G1 smartphone for the live street-view feature in Google Maps. You can checkout the video below to get an idea:
There are some other interesting uses of the magnetometer:
Examples of how this could be used include pointing your iPhone's
camera at a building and the phone telling you what building it is by
combining GPS, accelerometer and compass information. The iPhone could
even overlay graphics and text on top of the image to provide
additional information. Another application described is the ability to
show information about stars and constellations simply by pointing your
iPhone towards the sky.
So are you excited about a digital compass in Apple's next generation iPhone?
I think I'm way more excited about finally getting mms than the magnetometer. This feature would hardly serves us purpose if turn-by-turn didn't become available. Well I do speak for myself since stars don't really interest me, although maybe I'll finally catch one of those "once in a million years" events the news always likes to report.
Very interesting, never heard of the company before, yet they've been in business since 1996… From the datasheet they don't look that impressive and makes you wonder why Apple chose them, then again, they have a brance in California…
A few things to note from the datasheet: (Excuse the bad english, but this was quoted direcly from the datasheet)
"(4) Due to the built-in DAC for compensating the offset magnetic field, the position restraint with parts which generate the offset magnetic field such as speakers is reduced, and the degree of freedom about layout is expanded. Note 1)"
"(5) An EEPROM for storing the individual adjustment values of sensor sensitivity is built-in. The
adjustment values are stored in factory at the time of shipment from AKM."
Yet further down in the datasheet they caution users not to tamper with the EEPROM values…that means no user "calibration"
"Caution
Never write in EEPROM.
Device-specific adjusted values are stored before shipment in AKM. Write operation is not needed in user operation. It may loose adjusted values.
If these adjusted values are lost, AK8973 cannot operate normally."
"(6) The built-in temperature sensor as an accessory generates the 8-bit digital A/D-converted value.
The temperature information is not used for azimuth calculation."
So when the phone gets hot, as it usually does, we will get skewed results?
"Note 1) For AK8973, the offset magnetic field compensation range is approximately ±2.0mT (typical
geomagnetism range is approximately 0.05mT). Depending on usage or required accuracy, use with
the full-range is available. However, for the azimuth measurement by the mobile phones, it is
important to regard the following in the design phase: the magnetic field intensity of offset magnetic
field source (e.g. magnet of speaker) is not fully controlled, and the temperature characteristic
dispersion is noted. With AK8973, it is recommended that the design be performed with the parts
layout where the offset magnetic field of each measurement axis is ±0.8mT or less"
It would be interesting to see how it works, and how it affects the battery life. But agree that it is not really needed and MMS is higher on the priority list. Anyways, just my view of things…
I think I'm way more excited about finally getting mms than the magnetometer. This feature would hardly serves us purpose if turn-by-turn didn't become available. Well I do speak for myself since stars don't really interest me, although maybe I'll finally catch one of those "once in a million years" events the news always likes to report.
Very interesting, never heard of the company before, yet they've been in business since 1996… From the datasheet they don't look that impressive and makes you wonder why Apple chose them, then again, they have a brance in California…
A few things to note from the datasheet: (Excuse the bad english, but this was quoted direcly from the datasheet)
"(4) Due to the built-in DAC for compensating the offset magnetic field, the position restraint with parts which generate the offset magnetic field such as speakers is reduced, and the degree of freedom about layout is expanded. Note 1)"
"(5) An EEPROM for storing the individual adjustment values of sensor sensitivity is built-in. The
adjustment values are stored in factory at the time of shipment from AKM."
Yet further down in the datasheet they caution users not to tamper with the EEPROM values…that means no user "calibration"
"Caution
Never write in EEPROM.
Device-specific adjusted values are stored before shipment in AKM. Write operation is not needed in user operation. It may loose adjusted values.
If these adjusted values are lost, AK8973 cannot operate normally."
"(6) The built-in temperature sensor as an accessory generates the 8-bit digital A/D-converted value.
The temperature information is not used for azimuth calculation."
So when the phone gets hot, as it usually does, we will get skewed results?
"Note 1) For AK8973, the offset magnetic field compensation range is approximately ±2.0mT (typical
geomagnetism range is approximately 0.05mT). Depending on usage or required accuracy, use with
the full-range is available. However, for the azimuth measurement by the mobile phones, it is
important to regard the following in the design phase: the magnetic field intensity of offset magnetic
field source (e.g. magnet of speaker) is not fully controlled, and the temperature characteristic
dispersion is noted. With AK8973, it is recommended that the design be performed with the parts
layout where the offset magnetic field of each measurement axis is ±0.8mT or less"
It would be interesting to see how it works, and how it affects the battery life. But agree that it is not really needed and MMS is higher on the priority list. Anyways, just my view of things…
Thanks for the details, it will definitely be interesting to see what kind of iPhone apps make use of the magnetometer.
But yeah agree with you and hxclos, I'm not too excited about it.
It they get this we will be able to have the same metal detector app as the g1.
http://www.youtube.com/watch?v=MzSJKpsNUFo
I was messing around with it on my friend's phone, it's pretty awesome.
It they get this we will be able to have the same metal detector app as the g1.
http://www.youtube.com/watch?v=MzSJKpsNUFo
I was messing around with it on my friend's phone, it's pretty awesome.
It they get this we will be able to have the same metal detector app as the g1.
I was messing around with it on my friend's phone, it's pretty awesome.
It they get this we will be able to have the same metal detector app as the g1.
I was messing around with it on my friend's phone, it's pretty awesome.
yea an iphone metal detector would be badass ppl would be look i can play music with my phone id be like i can fucking detect metal with mine!