[chbot] Interesting presentations at our next meetings

[Volker Kuhlmann]

On Sat 28 May 2011 11:43:44 NZST +1200, Mark Beckett wrote:

> Nick is part of the Arduino forum, his write-up is very impressive.

Yes indeed!
You do get the same info from the datasheets of the various components
which is generally not too bad, but he's collated it very nicely.

> 1 Wire
> http://www.gammon.com.au/forum/?id=10902

That was pretty easy to do (Dallas DS18B20+ temperature sensors) with
the software online for Arduino. The only thing that tripped me up was
that the pull-up is required, after the datasheet proclaiming "no
external components required". It also works nicely over tens of metres
of cable, though the pull-up needs to be smaller (2-3.3k).

SPI + I²C are pretty much useless for that.

> SPI
> http://www.gammon.com.au/forum/?id=10896
I²C

The SPI one is here:
http://www.gammon.com.au/forum/?id=10892


Re I²C and SPI, I obtained some samples of some pre-production AD
temperature sensors using those 2 buses, but could not get either to
work. The issue seems to be that they are extremely sensitive to signal
shape, much more so than other SPI devices I bread-boarded onto an
Arduino test platform. These new sensors were absolutely no go with that
method.

Does anyone have more info whether my conclusion is correct, and/or what
the problem here is eaxctly?

Thanks,

Volker

-- 
Volker Kuhlmann
http://volker.dnsalias.net/	Please do not CC list postings to me.