IOExceptions while profiling / extruder excercising?

today i noticed that after running either the extuder excerciser or the heat profiler for a while (eg 30mins) the console starts reporting IOException due to timeout, and the temperature stops changing. the boards still work otherwise though, and the heater seems to be accepting commands because the blink rate changes occasionally.

is anyone else having this problem? it's a little concerning because in the absence of new temperature data, the heater happily burns away until someone notices.

(sorry i don't have the exact text of the error message available at the moment).

we are running the firmware binary zip from the sourceforge page (v1.0), and an svn checkout of the java software (circa 6 oct 2007).

pix.

it also seems that this happens repeatably when the reported temperature reaches 96

I've had some similar problems with the extruder firmware. It seems like there are just certain resistor values that the firmware doesn't like. I guess yours happens at 96 degrees. Mine would usually refuse to give me readings instead of IOExceptions, but I did see a few of those too. Sometimes it would start working again after the IOException. I was using firmware built from svn.

I've also had a few exciting times when the firmware locked up with the heater on 100%. It smells pretty bad the first few times it happens. If you can find room to mount a thermal fuse, it's not such a bad idea.

It'd be nice to have a page on the wiki for sharing the thermistor beta and rz values and what capacitor works well with them.