[TangerineSDR] Magnetometer Spec update to V0.3

[Tom McDermott]

Hi Nathaniel,

The Magnetometer RM3100 User Manual has this note attached to paragraph
5.2.1.:
----------------------
Note: The Cycle Count Registers establish the maximum data rate of the
sensors. For instance,
if the cycle count is set to 200 D , then the maximum 3-axis update rate is
~430 Hz. If TMRC is set
to 0x92, indicating an update rate of ~600 Hz, the rate established by the
cycle count will override
the TMRC request, and the actual update rate will be ~430 Hz.
-----------------------

For the PSWS application and using the range extenders, we would limit the
interface to 100 kb/s in
order to accommodate 30m of cable. In continuous mode, a measurement
reading takes 10 register
reads, with overhead that's about 90 bits, lets round up to 100 bits. That
is 1 millisecond to take
a measurement.   Thus the Magnetometer IC itself is the rate limit for a
cycle count of 200, and
the update rate would be 430 / second.


-- Tom, N5EG



On Thu, Jul 25, 2019 at 9:48 AM Nathaniel Frissell <nafrissell at gmail.com>
wrote:

> Hi Tom,
>
> This magnetometer document looks fine to me, and I think it will work well
> for our application. I see the that the resolution of this sensor depends
> on cycle counts, with 200 cycles for 13 nT. It also says the circuit
> operates at 180 kHz... so, am I correct in saying that could potential make
> 900 measurements/second?
>
> 73 de Nathaniel W2NAF
>
> On Wed, Jul 24, 2019 at 3:54 PM Tom McDermott via TangerineSDR <
> tangerinesdr at lists.tapr.org> wrote:
>
>> The magnetometer spec has been updated as a result of the 7/22/2019
>> TeamSpeak session.
>>
>> 1. Power supply is +5V only. I2C logic levels remain 3.3V.
>> 2. Add new use case for direct connection to local host not involving
>> Data Engine.
>>
>> Attached PDF.
>>
>> -- Tom, N5EG
>>
>>
>> --
>> TangerineSDR mailing list
>> TangerineSDR at lists.tapr.org
>> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>>
>
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