Hello,
I just began to use magnetometer sensor on the platform of MICA2.
Since we have some experiences to do with MICA, I am now able to get
sensing values. But my problem is that the magnetometer sensor seems to
only can detect moving magnetic field! What I mean is that when the
magnet is still, the sensor value we get from ADC is always 0 (or
almost 0) no matter how close and how strong the magnet is. But as
long as it moves, the sensor can provide values reflecting the
change of magnetic field strength. Does anybody have the same problem?
If you once had the same problem and have solved it, please tell me
your solution. If you haven't, welcome to send me email to discuss it.
Another problem is about the sensitivity of the magnetometer
sensor. I use a powerful magnet ring to give a magnetic field. But the
sensor only can detect it within about 1 foot (so weak, isn't it?). I
hear for others that some people claimed they can do measurement with
the distance of 2 meters. If you do, please tell me how and what kind
of magnet you use and other measuring condition.
The possible solution I can find is to set (reset) the
magnetometer sensor chip (HMC1002). I get information from
www.honeywell.com/sensing that we can use S/R+ and S/R- to set the
sensor to a high sensitivity state. I see that there are pads on the
sensor board connected to these two pins but not wired to any other
devices. May be the designer leave them for later use or have some
peripherals using them (I guess :)). If you know that, please let me
know. I will be very glad to have your suggestions and be very
thankful for your help.
Q. Zhou
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