[Solved] - New Thermistor not reading temperature correctly in RepSnapper - Help!

Hi,

I'm having problems with my thermistor and RepSnapper. I recently broke the thermistor so I put a new one on my heating block. I connected it all up and started RepSnapper.
I knew I needed to edit the thermistor table information to match the new thermistor, so I did that and compiled and reloaded the firmware.

However, the" current temp" box on the RepSnapper Print tab doesn't show the temperature correctly. It shows numbers round 639B, 723B, 780B, 663B, etc, etc. When I hold the block it doesn't seem to register any increase in temperature (from my body heat).

I even made another completely new heating block with a different thermistor (with different thermistor table information) but the same thing happens.

The thermistor table information I change is in the "temperature.h" file

Does anyone recognise this problem?
Am I doing something basically stupid?

Thanks

Pete

Edited 1 time(s). Last edit at 10/03/2011 06:35AM by Flackster.

You could check that the thermistor is functioning by measuring ohms resistance across the wires. If I recall it goes from high resistance, say 50 ohms to about .5 ohms at functioning temperature. exact numbers arn't important but yes temperature.h converts ohms to deg C. Take a hair dryer and see that the number changes when it gets hot, which says that the thermistor is functioning.
What you are seeing is the firmware transmitting the bed temperature then somewhere to the right it shows the extruder temperature.
Repsnapper only shows the left several charactors. So I don't know of a way to fix this in Repsnapper, maybe someone else does, however a change to a different firmware or a modification to your firmware would be the fix. I'm using tonokip and it transits the extruder temperature only to repsnapper.

Hi,

As was not completely unexpected, the fault lay with me

I'd connected the wires into my Molex connector incorrectly. Where I shoud have have the leads from the thermistor I had the ones from the heating resistor and vice versa. A quick swap and everything works again



Pete