Anyone using skr 1.4 or other lpc1769? Max temp errors with both temp sensors

[Matt Kulikowski]

Current marlin boots to max temp error which is set to 999 with both the 500 or 300 sensor across 3 new boards. 2.0.5.4 does not but reads 864 at room temp. 300 is new and 500 worked great with stock board and 2.0.5.2 actually read -50 at room temp. Had layer shift issues in y gave klipper a try and they went away but had other issues so wanted a 32 bit board with 2209 drivers and wanted to be able to edit stepper current without taking it apart to adjust pots. The pro apparently does not work with those and uart as I gave up and ordered one of those. Not sure if the gt has any issues but don't think I have the room for it anyway and didn't find any other 2209 boards.

Finally posted a bug but they so far just asked if temp sensors read correct with multimeter and temp tables are the same between versions.

[Philippe Carrier]

To read 864 and -50, I would guess that there is a problem with the wiring. I suggest the same as with the bug report, check the resistance at the wire. At room temp, you should have about 4.7MΩ for the high temp, 97kΩ for the 300°C.

[Matt Kulikowski]

Thanks,  I finally verified it is not a hardware issue for sure, built Marlin 2.01 with same settings with the 500 and instead of reading max temp fault or over 860C at room temp it reported 20 and just did a successful auto PID to 200 using the same wiring and hardware just lower build.  No luck with 2.05.2 either.  Had to edit pins file of 1.4 non turbo to make it a lpc1769 not 1768 and didn't edit any movement settings but it's working fine temp wise and I've tried many times from 2.05.2 to 2.07.2 so something changed Marlin wise.  Link to bug below.

https://github.com/MarlinFirmware/Marlin/issues/20470