Active low step pins

[executivul]

I'm trying to use g2core on an Arduino Due with level converters and externals TB6560 drivers which require active low step signals. How can that be accomplished? Thank you!

[aldenhart]

This is on the immediate roadmap. I expect sometime in the next few weeks to edge. Alternately, an external inverter can be used.

[executivul]

Thanks. I've tried changing false->true in motate step pin defs for due and recompiling everything but didn't work. I shall wait for the changes frome someone more skilled than me and run on grbl until then. I'm already using txb0108 level converters I've tried some mosfets (irlz44n) which I had on hand but the signal was bad on the scope and I gave up, adding more circuitry is prone to missing steps and problems I'm affraid.

[giseburt]

As a quick fix, to reverse the step pin (only) for ALL motors, you can do the following:

In g2core/device/step_dir_driver/step_dir_driver.h line 55: ( https://github.com/synthetos/g2/blob/edge/g2core/device/step_dir_driver/step_dir_driver.h#L55 )

Change: OutputPin _step;

To: OutputPin _step{kStartHigh};

That will make the step pins high at boot up.

Now to make the pins invert, at lines 128-130 of the same file ( https://github.com/synthetos/g2/blob/edge/g2core/device/step_dir_driver/step_dir_driver.h#L128-L130 ) invert set() which sets the pin high and clear() which sets it low:

So, this: void stepStart() override { _step.set(); };

void stepEnd() override { _step.clear(); };

Becomes: void stepStart() override { _step.clear(); };

void stepEnd() override { _step.set(); };

With those changes, all step pins will start HIGH, and then will be pulsed LOW and returned to HIGH in order to step the motor.

Hopefully that helps.

-Rob On Fri, Jan 13, 2017 at 7:26 PM executivul notifications@github.com wrote:

Thanks. I've tried changing false->true in motate step pin defs for due and recompiling everything but didn't work. I shall wait for the changes frome someone more skilled than me and run on grbl until then. I'm already using txb0108 level converters I've tried some mosfets (irlz44n) which I had on hand but the signal was bad on the scope and I gave up, adding more circuitry is prone to missing steps and problems I'm affraid.

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[executivul]

Thank you! That did the trick!

[Hecatron]

Just to add to this would it be possible to add in a feature to invert the enable pin for the motor at some point? the RAPS128 Pololu driver has an inverted enable pin for activation I can already work around this by hacking the source code but it'd be nice if it was something that could be set within the settings

Also I should be doing a pull request in a short while for the RADDS board from ooznest