George > wrote:

>On 7/10/2011 1:10 PM, Steve Pope wrote:

>> > wrote:
>>
>>> On 7/10/2011 1:04 AM, Steve Pope wrote:

>>> My phone has a magnetometer and there is an app that exposes the data
>>>from it on a compass display.
>>
>> Cool, I did not realize this was an available cell phone feature.
>>
>> Steve
>
>I don't know how common that is. It actually is pretty amazing when you
>think about all of the stuff they can "bake in" to a smart phone and how
>little it costs. It also has a solid state gyro.

I've spend a good part of my career designing the innards of cellphones.
Much less time actually using them.

The reason they can get all those features in is that the products are
such high volume. A particularly high volume cellphone chip might
conceivably sell one billion units over its lifetime. So it justifies
teams of hundreds of engineers adding features to the chip.
When I worked for Texas Instruments we sold 2 million chips per day
that went into cellphones.

There are some higher volume chip products, such as the RFID tags
that go into retail products on the shelves. There might be
5 billion of those sold per year. Possibly more at this point.

>I discovered the magnetometer feature by accident. Nothing in the native
>interface displays it. I installed an app to get more info about how the
>GPS operated for something I was trying to do and noticed it gave me
>information about the strength of the earths magnetic field and had an
>option to display a compass. At first I thought it was a pseudo compass
>like you typically see on a GPS but I disabled the GPS and it still
>worked. I then moved a big nail nearby and the weak field from the nail
>affected the reading.

Cool

>The other amazing thing is the quality of the GPS chipset. It can often
>see 5 satellites inside the house in the same location where my older
>handheld GPS sees nothing.

I'm also really pleased with the audio quailty and camera quality
on my phone, and it's not particularly high end. Even the FM radio
works really well.


Steve