[PD] Sensors GPIO Raspberry Pi Pd

[Julian Brooks]

  and there's a document there that has something about using multiple
> sensors on one bus:
>
> http://www.mouser.com/catalog/specsheets/D6T-01_ThermalIRSensor-Whitepaper.pdf
>
> That's a much better doc.


Seems to me the easiest way to multiplex them would be to put a CD4051 on
> the clock line and use up to 3 GPIO pins to select which of up to 8 sensors
> receives the clock. The only tricky bit would be making sure the clock is
> at the right level when the switching tales place, you might need ~10k
> pullups to 3.3V on the sensor clock pins.


(did you spot my previous post with this and if so would that work?)

 Yes that's what happens already. I was getting errors at first because the
crc calculation was being done over both the write and read packets. I
found that calculating only the read         packet gives the correct value
almost always. If the PEC is wrong, the code simply asks for another
packet. At the moment I'm getting almost no errors

Maybe there's something I'm missing here then:

The average temp that comes out of [unpack 1] is way higher than the rest
of the readings.  At the moment [unpack 1] says '212' yet a quick averaging
of the other 16 readings is around '180'?

>
>
Yes, it even works as an icecube detector!


:D
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20130423/8dd13d6d/attachment.htm>