PT100 Reads 2000C With PanelDue7 Plugged In Via 10 Pin Cable

[michaelg-filamentinnovations]

Hello Everyone,

We are upgrading our BFP-ICARUS units to PT100 sensors on the Dyze Pro hotends, and we noticed, upon installing the PT100 with the appropriate adapter board, the temperature will read 2000C with the PanelDue7 plugged in with the 10 pin ribbon cable. When the cable is unplugged, the PT100 works great and has an accurate reading. We used the four pin cable in the mean time to be able to use the touchscreen with the unit, but is there something we can do to be able to use the PT100 sensor and the PanelDue7 screen with the 10 pin ribbon cable? Somehow using the 10 pin ribbon cable is causing interference with the PT100 sensor and we are not sure how to troubleshoot this further. Some of our customers do not have Wifi and rely on offline printing via the MicroSD card on the touchscreen.

Thanks!
Mike

[Phaedrux]

How is the PT100 wired? 2, 3 or 4 wire?

[michaelg-filamentinnovations]

Thanks for the reply @Phaedrux .

It is a 2 wire PT100 using the Duet Daughter board.

[Phaedrux]

Splicing the 2 wire to a 4 wire connection back to the daughter board should increase the resistance to interference.

But maybe @dc42 Has some insight why that may be happening with the ribbon cable.

[michaelg-filamentinnovations]

@Phaedrux Appreciate the info. We are open to ideas. We need to be able to give our customers a way to print offline - so I’m open to trying any ideas you or @dc42 may have.

Thanks!
Mike

[Phaedrux]

Have you seen this?
https://duet3d.dozuki.com/Wiki/Connecting_PT100_temperature_sensors#Section_To_connect_a_4_wire_PT100_sensor

[michaelg-filamentinnovations]

@Phaedrux - we did follow that page for setup, but I did not see the two to four wire conversion for the daughter board. I’ll try that tomorrow and report back. Thanks for the tip!

Mike

[dc42]

It sounds to me that there is a short between the SPI signals on the PanelDue. Is it an integrated PanelDue, or a separate controller and display?

Check for solder bridges between the pins of the ribbon cable connector on the back of the circuit board of the PanelDue.

[michaelg-filamentinnovations]

@dc42 said in PT100 Reads 2000C With PanelDue7 Plugged In Via 10 Pin Cable:

PanelDue

Thanks for the reply @dc42 and @Phaedrux .

Looks like the problem is solved - must be a short on the PanelDue7i screen. I took another one from inventory and swapped them out - everything is working fine. Thank you both for your suggestions!

@dc42 - Is there anything we can do to fix the one screen we have? Or do we need to write it off?

Thanks!
Mike

[dc42]

@michaelg-filamentinnovations said in PT100 Reads 2000C With PanelDue7 Plugged In Via 10 Pin Cable:

@dc42 - Is there anything we can do to fix the one screen we have? Or do we need to write it off?

Did you check for shorts between pins on the underside of the 7i PCB where the ribbon cable connector is soldered to it? Also check for shorts between the pins of the SD card socket.

[michaelg-filamentinnovations]

@dc42 @Phaedrux

Apologize for the late reply here - but here are some pictures if you see anything I missed.

Thank you!

[dc42]

I can't see anything obvious. How long is your ribbon cable?

[michaelg-filamentinnovations]

I couldn’t see anything either - glad I’m not going crazy! Ha.

It is 350mm using 26awg ribbon cable we buy from 3M. We make the cables in house.

I tried another (third) screen and that one worked too, just not sure why the first one won’t work with the PT100.

[dc42]

Somewhere on that screen there is a short between the SPI signal conductors between the ribbon cable socket and the SD card, or to ground. I suggest you ask your supplier for a replacement.

[michaelg-filamentinnovations]

Will do - thanks @dc42!

Mike