Temperature Reading Issue with NTC 10k B3950 Thermistor on Octopus V1.1

[H3DA]

Hi everyone,

I’m having trouble with temperature readings on a newly assembled Voron 2.4 350mm equipped with an BTT Octopus V1.1 board. I’m using a 10k B3950 NTC thermistor to measure the chamber temperature, but Klipper is showing incorrect readings (for example, 80°C instead of 20°C at room temperature).

I've already tried two new thermistors, and I’m still getting the same incorrect readings, so it doesn't seem to be a sensor issue. My current configuration in printer.cfg is as follows:

[temperature_sensor chamber_temp]
sensor_type: Generic 3950
sensor_pin: PF5
min_temp: 0
max_temp: 100
gcode_id: chamber_th

For reference, I also have a Voron 2.4 300mm and a Trident 250mm, both working without issues. Has anyone experienced a similar issue or knows how to fix these readings on an Octopus V1.1?

Any advice would be greatly appreciated!

 

[CurlyJ]

You might have made the mistake of buying the same 10k 3950 sensors I got.

A generic 3950 is expected to be a 100k resistance.

Here's the config I used to use the 10k:

[thermistor generic_10k_3950]
  temperature1: 25
  resistance1: 10000
  beta: 3950

[temperature_sensor chamber_temp]
  sensor_type: generic_10k_3950
  sensor_pin: PF5
  {The rest as you see fit}

 

[H3DA]

You might have made the mistake of buying the same 10k 3950 sensors I got.

A generic 3950 is expected to be a 100k resistance.

Here's the config I used to use the 10k:

[thermistor generic_10k_3950]
  temperature1: 25
  resistance1: 10000
  beta: 3950

[temperature_sensor chamber_temp]
  sensor_type: generic_10k_3950
  sensor_pin: PF5
  {The rest as you see fit}

Thanks, that fixed it! Accurate readings now. Appreciate it!