Control Knob Fails to Change Numeric Values After FW Update [Solved]

[ironcoot]

Was able to change numeric values (such as "bed temperature" and "Z position") reliably on unadulterated Rostock Max V2. Firmware was 0915 (downloaded 07 Aug 2015).

Ran EEPROM_clear and loaded 0.92.2 (20170328) firmware on the Mega 2560 (after edits to Configuration.h).

Immediately noticed that control knob required two clicks to advance one line in menu, and later discovered that numeric changes would not occur.

Further issue - attempt to change Z position using knob rotation resulted in card reset (!!).

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Ran EEPROM_clear and loaded 0915 firmware again. (Same directory used in 2015, "arduino" standard IDE 1.6.4.)

Control rotation knob functions now requires only one click per menu item and will alternate between the status displays (as it did in the past) -- however numeric entry still does nothing. The asterisk appears next to the field name when the knob is pressed, but twisting the knob does not change the value ("bed temperature"). Pressing the knob again returns to menu selection.

An additional problem is that when trying to change "Z position" by rotating the knob -- the extruder servo (!!) to turn on.

G-code commands to change Z position issued from Pronterface function correctly in the second-0915 load. Also single-click actions like "home" work properly on knob press.

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Questions:

is there any possibility that the IO pins on the M2560 could have been programmed by accident to persistently disrupt (just) numeric entry using the control knob? (Again, menu selection using knob rotation works fine.)

Is there anything in the arduino IDE releases that would change how the M2560 firmware handles knob rotation?

Thank you in advance for any clues.

[ironcoot]

The fatal control knob behaviour was cleared up by running a newer version of the Arduino IDE (1.8.4).

Now I can get on to other mysteries.