On Fri, Mar 22, 2024 at 3:57 PM <karl@???> wrote:

> o1bigtenor:
> > On Fri, Mar 22, 2024 at 4:02 AM Lars Noodén <lars.nooden@???> wrote:
> > > On 3/21/24 23:13, o1bigtenor via Dng wrote:
> ...
> > > > (Another project where it would be nice to be able to use a PID
> control
> > > and
> > > > be able to read 'accurately' and repeatedly to +/- 0.1C (process
> > > > requirement!).)
>
> ±1 °C is easy, ±0.1 °C is very hard. Be prepared to set up a
> calibration routine if you really want that and I suggest using higher
> quality PT100 sensors.
>

There was a response that talked about 'wiring' to achieve a +/- 0.1C
control which is why I was asking!

Am quite aware that the needs are different - - - - I will be quite happy
if
I can reasonably create a +/-0.2C control in fact (for that other project).

>
> ...
> > > DS18B20
>
> I have used that one, you can attach a multiple of them to a three wire
> cable ("1-wire" bus). Also you can start the temperature conversion with
> a single command (like a broadcast), though I had problems with them in
> the long term. Some dropped out, didn't investigating it further.
> I have some code and designs if you're interested.
>
> ///
>
> The -40°C qualification isn't hard to attain, just use suitable grade
> of components, high humidity is a bigger problem, water always finds
> it's way everywhere long term, but it helps to keep the electronics
> warmer than the air. You could also coat the boards.
>
> You could use:
> . (long) cables from each sensor to a central warm and dry enclosure
> . "die cast" (what is the right word) the sensor electronics and use
> water sealed connectors like thoose found in cars and use a CAN or
> RS485 bus
>
> ///
>
> I have some designs and code at (stm32f1 centric):
>
> https://aspodata.se/git/openhw/
>
> Currently working on
> https://aspodata.se/git/openhw/boards_arm_aspo/stm32f100_styrkort/
> which contains pt100 inputs, relay outputs, 0-10V outpus and a "1-wire"
> interface; communication via rs-232.
>
> Give me a call if you need more help.
> I use:
> https://graahnul-grom.github.io/ref-manual/lepton/index.html
> http://pcb.geda-project.org/
>
> (you could possible replace pcb with pcb-rnd:
> http://pcb.geda-project.org/)
>
> Very fascinating (your last section!!).

Would you be up to some private questions?
(I am only at the start of this journey and am finding it more difficult
than
I would like finding unbiased information! (If there is such a thing - -
grin!))

Thanking you for your ideas and your time!!!