499 Deg. Temp. Reading

Hello Everyone,

I'm playing around with the Marlin firmware on a new Arduino/RAMPS 1.4 combo and I'm getting a 499 degree reading from the hot end in Pronterface.

Even when there is no thermistor connected.

I've been trying to set things up for dual extruders.

Any ideas what is going on? Just another defective RAMPS?

I should add I moved around some tested thermistors and still get 499. Only when I put a jumper on the two T0 pins does temp drop to 0.

Edited 1 time(s). Last edit at 02/17/2015 02:50PM by Yvan.

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Yvan

Singularity Machine

I experinced the same (reading of 499 degress) before actually connecting a thermistor to the RAMPS board and enabled the temp sensor setting in the Marlin configuration so I do not think you have to worry about this since it is a dummy value set in absence of a real sensor value.

To get a "real" value, make sure to connect the extruder thermistor to the RAMPS board, enable the temp sensor in the firmware configuration and upload the new firmware to the arduino board.

This is how the extruder temp sensor is configured in Marlin:

#define TEMP_SENSOR_0 1

The value 1 may have to be changed in order to reflect the thermistor type you are using. Check the thermistor table in the file!

/Henrik

Yes, I see what you mean now. I was able to return to the original firmware settings and with a thermistor got normal readings.

I have to set this aside, but I want to tackle all of this again because I have a dual extruder system I want to install on one of the machines.

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Yvan

Singularity Machine