Geeetech

I am having trouble with my E3D PT100 temperature sensor when it is connected to my GT2560 board. If I disconnect the amplifier from the GT2560 I get exactly what I should, 1.211 volts. When I connect the temperature sensor to the GT2560 it changes to 1.289 volts. This throws my temperature off by 17 degrees c. I am using Marlin 1.1.9 table 20 for the PT100. Is there a different table I should use? Is there a reason the voltage changes? Any help would be appreciated. Thanks.

Hello.


Is it possible that you have an element with the wrong resistance? Other type?
Otherwise you would have to use offset in the code.

I could see the sensor being wrong if I didn't get the right voltage value with the amplifier disconnected. It's the change in voltage when it is connected that is the problem. E3D is sending me a new sensor and amplifier to see if that is the issue and I will update this post when I try this out.

Received the new PT100 sensor and amplifier board from e3d and have pretty much the same results. 1.119 volts with the signal pin not plugged in and 1.278 volts with it plugged into temp0 input pin. The power for the amplifier is being taken from the modified Y max input (changed connector to get the +5v and ground) The voltage to the amplifier board is 5.00 volts. Something is shifting the output up and I can't figure out what. I could just offset table 20 in marlin for the different voltage but I don't know if this would be linear. Any ideas?

1.119 volts with the signal pin not plugged in. I couldn't figure out what has shifted the output.
airgunmaniac