Seeking your opinion on ways to report both Altitude and Pressure sensors for the DPS310 as well as Temperature from dbus-sensors.

[Ed Tanous]

On Tue, Jun 1, 2021 at 8:43 AM Bruce Mitchell
<bruce.mitchell at linux.vnet.ibm.com> wrote:
>
> Hello Ed,
>
> It has been suggest I seeking your opinion on ways to report both
> Altitude and Pressure sensors for the DPS310 as well as Temperature from
> dbus-sensors before going to far down the road.  Thus that is what I am
> attempting to do in the email, others on the mailing list input is
> desirable as well.

Thanks for discussing this before getting too far along.  I haven't
worked on any systems with physical pressure sensors, but I'm excited
to see new things get added.

>
> As I see it, Altitude and Pressure are different in that
>      1) Altitude is computed base off of essentially a policy

I have no idea what this means.....   In what way is altitude a
"policy"?  Can you elaborate a little?

>      2) Pressures is a read measurement which is a mechanism
>      3) Temperature is a read measurement which is also a mechanism

I'm really struggling with the above to understand what you're getting
after, so if I go down the wrong path, please forgive me.

I think what you're saying is that altitude is calculated based on
pressure + some transfer function to determine an altitude?  And that
transfer function might be fungible depending on the platform?

If I got the above right (big if) I would probably expect a new
pressure sensor type to be added that reports a pressure sensor, then
we'd put the transform code in something that looks a lot like CFM
sensor (which oddly enough has a hardcoded 0 for altitude in its
algorithm for systems without pressure sensors).  Considering how
related a pressure sensor is to altitude, I could see putting them in
the same application if you wanted;  It might simplify the code some.


I think overall a better picture of what you're wanting to accomplish
would be a good place to start, then we can iterate from there on what
pieces we need that are new.

>
> Thank you!
>
> --
> Bruce