Rat Rig Community [Unofficial]•3y ago

[Solved] All PT1000 sensors showing 13 degrees higher

Happens to every PT1000 sensor, temperature is normal when I use 104NT-4 sensors

inadequate-blush•1/14/23, 11:12 PM

same here , hope someone will help

ptegler•1/15/23, 1:48 AM

did you set your dip switches on your control board for the PT1000? 1000 is not a direct plugin replacement without settings changes

Pptegler did you set your dip switches on your control board for the PT1000? 1000 is no...

NecroDavidOP•1/15/23, 2:52 AM

I use Octopus Pro board, which supports plugging PT1000 into the thermistor slots directly.

ptegler•1/15/23, 2:53 AM

yes but you need to set SW3 OFF (1,2 and 4 stay on ) read your manual

ptegler•1/15/23, 2:53 AM

I too use an octopus pro 446

ptegler•1/15/23, 2:55 AM

section 4.5 of the users guide

Pptegler section 4.5 of the users guide

NecroDavidOP•1/15/23, 3:03 AM

Like so?

ptegler•1/15/23, 3:03 AM

yes

ptegler•1/15/23, 3:05 AM

pt1000 is less accurate at lower temps but more at higher as well as able to read higher temps. These switches change the resistance values on the bridge that reads the sensor

ptegler•1/15/23, 3:05 AM

after a reboot...did your reading change to something much closer to expected?

NecroDavidOP•1/15/23, 3:06 AM

Do I need to reboot the whole pi or just Klipper?

ptegler•1/15/23, 3:07 AM

not sure. You could try just klipper but the board might need to see a cycle to re-read those switches

NecroDavidOP•1/15/23, 3:08 AM

I mean it didn't change after firmware restart. Let me try rebooting the pi

NecroDavidOP•1/15/23, 3:09 AM

Rebooting the Pi also made no difference

ptegler•1/15/23, 3:10 AM

power cycle is all that's left. I'm not sure how else to have the BBT board re-read the switches (not sure how Klipper firmware works o tneh board)

NecroDavidOP•1/15/23, 3:11 AM

I did power cycle it

ptegler•1/15/23, 3:12 AM

sensor on the connector center two pins?

ptegler•1/15/23, 3:13 AM

BTT_Octopus_pro_EN.pdf2.8MB

ptegler•1/15/23, 3:14 AM

pages 19-21

NecroDavidOP•1/15/23, 3:16 AM

I use the connector shown on the RatOS wiring diagram

ptegler•1/15/23, 3:20 AM

did your reading change? or still the same?

ptegler•1/15/23, 3:24 AM

?? https://os.ratrig.com/assets/files/octopus-pro-wiring-full-3d9d989a41707c83aaebfd75f2ed3846.png doesn't even show the hotend ot therm. Go by the board manual for that

NecroDavidOP•1/15/23, 3:27 AM

Many others are wiring the PT1000 this way, and they had no problems

NecroDavidOP•1/15/23, 3:33 AM

I do it here

ptegler•1/15/23, 3:47 AM

dumbass me! Sorry David...I dumped those last message.... I was mixing boards in my head even though I was looking at the docs. I just looked at my own board when I started questioning my own comments. Yes indeed your wiring is i nthe right place. And again.... did the reading change with the switch change?

ptegler•1/15/23, 3:54 AM

And now you have me questioning the oem RatOS configuration... as the hot end thermo is configured on the Octopus board as PF4 which is where you have your sensor. The connector for the PT1000 using the switches uses the max31865 chip and uses those switches. So how is MS (author/maintainer) handling the PT1000?
I'm headed over to my printer now to flip SW3 and see what changes (if anything)

NecroDavidOP•1/15/23, 4:05 AM

No, the switch did nothing, it is still showing wrong readings

ptegler•1/15/23, 4:52 AM

Just did a whole bunch of digging.
Looking through the example config files, it's not obvious, RatOS is even using the MAX chip or that socket at all! The Hotend sensor (E_sensor_pin)is on PF4 which is that socket you are plugged into. The MAX chip uses PF. So the question arises.... how in firmware is Klipper connecting the correct resistance to read the PT1000 correctly (if it does at all). In that latter case, it would explain your errored reading. BUT, then I have to wonder why min reads correctly.

ptegler•1/15/23, 4:54 AM

PT100 uses a 430 ohm and PT1000 would be a 4300 ohm resistor for the MAX chip to read and use the full range scale of the Pt1000 (vs PT100) . This 'scheme' is the same on a Duet3D board (changing values for the bridge reading the sensor) So I guess I need to dig into the firmware if I expect to understand what the connection of PF4 vs the MAX chip pin connections is. need