Temperature readout constant

I have a GEN3 mendel setup. The firmware that does currently work for both the reprap motherboard and the slave extruder board were taken from [www.mendel-parts.com]

communication from the motherboard to the slave extruder works (motor, and heater). The only thing that doesn't seem right is the temperature readout. Without the heater switched on (room temperature) I get this (through repsnapper):

--> N187 M105*41
<-- T:95

<-- ok

Switching on the heater (yes, it gets really hot), doesn't change the readout. Any suggestions?



The temp table I have both set in the Extruder and FiveD is as follows for a 100K ohms VISHAY thermistor:
// VISHAY NTCLG100E2104JT NTC 100kOhms 5%
// Thermistor lookup table for RepRap Temperature Sensor Boards (http://make.rrrf.org/ts)
// Made with createTemperatureLookup.py (http://svn.reprap.org/trunk/reprap/firmware/Arduino/utilities/createTemperatureLookup.py)
// ./createTemperatureLookup.py --r0=100000 --t0=25 --r1=0 --r2=4700 --beta=3977 --max-adc=1023
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 3977
// max adc: 1023
short temptable[NUMTEMPS][2] = {
{1, 913},
{54, 264},
{107, 215},
{160, 189},
{213, 171},
{266, 157},
{319, 145},
{372, 135},
{425, 127},
{478, 118},
{531, 110},
{584, 103},
{637, 95},
{690, 88},
{743, 80},
{796, 71},
{849, 62},
{902, 50},
{955, 34},
{1008, 2}
};

Some extra checking releveals:

* wiring the thermistor directly to a multimeter shows there is not short circuit on the 100k thermistor assembly
* measuring the resitance over the two screws where the thermistor should is 0 Ohms... is that right?
* [wiki.makerbot.com] (little program to read out the temp sensor) shows the exact read out (649 94 : 419 56
) with or without the thermistor connected.

The problem is very likely on the board. Helpfull hints how to check this are

You may want to find a way to measure temperature independent to the harware and software. Determine if it is stable or not. If stable and you just aren't getting the readings to show up in Repsnapper, its probably a firmware issue not transmitting temperature back to the board in the format Repsnapper wants to see. I tried but gave up on Gen3 because it either didn't have the power to keep up or good firmware wasn't avaliable.

How did you check if the MB and EC communicate? If you unplug the RS485 wires between them, do you still get a temperature reading? Did you configure the firmware for Gen 3 with off board temperature controller? Note that the extruder stepper motors will still run even if there's no communication between the board as long as the firmware is running on gn EC and the Step and Dir lines are connected.

FYI. Attached is screen grab of the format used to send temperature readings to repsnapper and that is displayed prefectly in the Current Temp window. Controller sends out a M105 and the board responds with a T:86.00 with parameter 86.00. I hope this helps.