Thermistor and Thermocouple won't work together

[balvenie 0]

Hello,

I have a Problem with my DIY UMO.

I installed a Thermocouple for the Hotend, like Ultimaker does as well.

It Works just fine if i define everything like it is told in this wiki article:

http://reprap.org/wiki/ExtThermoCouple_1.0

But i now installed a heated bed with a Thermistor. When i declare it in my marlin fimware its not working. Both are measuring the temp. correct. (tested it with a lighter). But Cura does not allow to heat up the Hotend.

#define TEMP_SENSOR_0 -1

#define TEMP_SENSOR_1 0

#define TEMP_SENSOR_2 0

#define TEMP_SENSOR_3 0

#define TEMP_SENSOR_BED 1

I always get this message:

Error:Heated bed switched off. MAXTEMP triggered !!

Error:Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)

If install 2 thermistors, one for extruder and one for the heated bed everythings just working fine.

#define TEMP_SENSOR_0 1

#define TEMP_SENSOR_1 0

#define TEMP_SENSOR_2 0

#define TEMP_SENSOR_3 0

#define TEMP_SENSOR_BED 1

What am i doing wrong?

Hardware: DIY UMO

Electronics: Ramps 1.4

[gr5 2,172]

What are these values set to?

 

#define BED_MINTEMP 5
#define BED_MAXTEMP 150

Also how *long* does it take for the error to occur? Immediately? Or after 10 (or more) seconds?

I recommend you go here

http://marlinbuilder.robotfuzz.com

and experiment with your current setup and only download Configuartion.h and use a program like winmerge to compare the Configuration.h files that you edited versus robotfuzz created.

 

Both are measuring the temp. correct. (tested it with a lighter). But Cura dows not allow to heat up the Hotend.

 

Yes but are both in the range above?

 

[balvenie 0]

#define BED_MINTEMP 5

#define BED_MAXTEMP 150

These are the values in my config.

The failure occurs immediately.

Tomorrow I will check it by comparing the files with winmerge.

EDIT:

Yes the measured and displayed temps are in the range above.

 

[balvenie 0]

The weird thing is, that the thermocouple works if i do not define a second temp. sensor (the one for the heatbed) in the marlin firmware.

If i only use the thermocouple everything works fine.

Even if i use for hotend and heatbed a thermistor and do not use the thermocouple, it works.

But i really want to use my thermocouple ;-)

 

[gr5 2,172]

Yes, I noticed that. Very strange. I'll get Daid to take a look at this thread. He knows Marlin much better than me.

 

[balvenie 0]

I compared the file I generated with the file from the marlin builder. There are no differences that could have an effect.

Does nobody else have an idea?

 

[anon4321 16]

How do you have the pins defined? Is it possible you have the same pin assigned for both?

If not, does the thermocouple read correctly? In other words does it read room temperature?

How about when the thermisistor use used for both? Do they both read room temperature?

Do you have the pullup in correctly when using the thermisistor?

 

[balvenie 0]

The Pin for the thermocouple board is defined as pin 3.

Thats the only change I have done at the pins definition.

In every config the thermistors and the thermocouple or both thermistors read room temp.