[Oberon] PO2013 - Real time measurement

[Tomas Kral]

Hi Joerg,

> you could connect the HW probe directly to the Oberon system without
> using the mentioned PIC chip.

True, possibly with use of A/D converter, or with a probe
outputting /D directly.

> Try to see the Oberon system as kind of PIC with the benefit of being
> programmed in Oberon instead of eg C for the PIC.

Point taken, but after reading `A Microcontroller System for
Experimentation' with PIC, I felt equally tempted to do my own
experiments with a breadboard. There is one experiment with thermo probe
here,
https://inf.ethz.ch/personal/wirth/PICL/PIC.pdf

Then I found this page on NTC,
http://www.giangrandi.ch/electronics/ntc/ntc.shtml,
that made me hooked, there is a voltage divider, that needs Vref to feed
A/D input. I hope this is the way to connect to PIC.

As R(T) is non-linear, some calculation is required, I need to find
about yet.

I would like to start with `NTC-0,2 6,8K' just for ambient
temperatures. I would not know yet, how to choose suitable R25 for other
work ranges, as I believe the narrower work range the higher precision,
possibly.

-- 
Tomas Kral <thomas.kral at email.cz>