Memsic 2125 and BS2p

Archiver

I am trying to use the 2125 with a BS2p instead of the BS2 which all
the example code is for. Can anyone out there give me example code
for measuring tilt using the 0.75 us resolution of the BS2p instead
of the 2 us res of the BS2?

Trent

Archiver

Hi,
Thanks for the clarification on rotation.

You can download the memsic example programs for bs2 here
<http://www.parallax.com/detail.asp?product_id=28017>
and make the necessary adjustments for bs2p.

To get acceleration this algorithm is used:
A(g) = ((T1 / T2) * 0.5) / 12.5%
Where T2=10ms.

On the BS2 it looks like this:

Read_X_Force:
PULSIN Xin, HiPulse, xRaw
xGForce = ((xRaw / 5) - 500) * 8
RETURN
Where xRaw=T1 5=T2*2µs(for bs2) and 500=500µs=.5ms and 8=1/12.5

So the only number that needs to be adjusted is the one that represents T2.
It should be 13.3333 for the bs2p's .75µs periods (13.33333 * .75 = 10). You
can multiply both sides of the fraction by 3 to get rid of the decimal.

For a BS2p Try this:

Read_G_Force:
Pulsin Xin,HiPulse,pulse
xmG = (((pulse * 3) / 40) - 500) * 8
Pulsin Yin,HiPulse,pulse
YmG = (((pulse * 3) / 40) - 500) * 8
Return

I'm not a hundred percent on this, but a similar adjustment is working for
me on the .8µs BS2sx.

Cheers,
Nick



on 09/14/03 4:29 PM, ScoobyTW at scoobytw@y... wrote:

> I am trying to use the 2125 with a BS2p instead of the BS2 which all
> the example code is for. Can anyone out there give me example code
> for measuring tilt using the 0.75 us resolution of the BS2p instead
> of the 2 us res of the BS2?
>
> Trent
>
>
>
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Archiver

That did it! Thanks for the help.

Trent

--- In basicstamps@yahoogroups.com, nick stedman <nickstedman@s...>
wrote:
>
> For a BS2p Try this:
>
> Read_G_Force:
> Pulsin Xin,HiPulse,pulse
> xmG = (((pulse * 3) / 40) - 500) * 8
> Pulsin Yin,HiPulse,pulse
> YmG = (((pulse * 3) / 40) - 500) * 8
> Return
>
> I'm not a hundred percent on this, but a similar adjustment is
working for
> me on the .8µs BS2sx.
>
> Cheers,
> Nick
>