Attaching multiple temp sensors

[LarrylLix]

This sounds like you are well on you way then!
 
Just try one step at a time so that if problems start then you know what is the cause. Try the 40' long cable and if it gives problems add a terminator resistor at the farthest connection.
 
If you have a few sensors at the far end you may not need a termination resistor as there may be enough "absorption" to not be bothered by reflections in the cable.

 

[rfeyer]

Ran into a little problem, actually.
I had 2 sensors connected directly to the WC8, then, with a third line, attached the other 3 at 3m length.
Now only one or the other show - the first two or the last 3. Guess I should have followed the initial thread and used it in daisy chain.
Will try to change it next weekend and see how it goes.
The sensor witer are pretty fragile, a little tough to work with.
 
Rainer

 

[LarrylLix]

I had several sensors that just wouldn't show until I did a few reboots. It did seem that longer power off cycles seemed to help.
Try it.
 
Leave the power off for about 60 seconds. These sensors are made to run by "stealing" micro power from the data line if desired so they should have a carry over capacitor in them that can keep them alive for a long time.
 
With 3m cables you shouldn't have too much problem. they may be  bit flaky but mostly function or at least show up in the setup screen. 

 

[pittom]

I have a total of 6 temp sensors all on separated wires
1- 35 feet 
3- 6 feet
1- 10 feet
1- right on the board
 
Never had a problem 3 years of non stop running outside with temps ranging from -15f to 120f

 

[rfeyer]

LArrylLix -That is great advice about booting down for 60 sec - will try tomorrow.
Pittom - Ty also for the display of cable lengths - now I do not have to worry as the next board with sensors will go into the house.
 
Rainer

 

[Efried]

Hope this helps: avoid star topology http://www.maximintegrated.com/en/app-notes/index.mvp/id/148

 

[rfeyer]

That certainly helps a ton!
 
I currently do have it connected in a star like fashion, however, just received my 3 position PCB terminals yesterday and should be able to get a board made up this weekend.

TY!

Rainer
 
Electronics isn't easy, eh?