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Topic: How to add/repurpose hardware inputs to Solidoodle?

I'd like to experiment with adding functionality to the Solidoodle by either adding one or more additional switched inputs or dual-purposing one of the existing ones (e.g. bed temp, extruder temp, endstop switches).  Some ideas that come to mind include an automatic probe/procedure to check bed leveling, a touch probe to 3D-scan objects placed on the bed, or an automatic shutoff switch that kicks in when a print breaks free and touches a perimeter wire erected around the print bed.

Does the Sanguinololu have additional input channels available?  How difficult are they to access, and what firmware mods are necessary?  Which, if any, of the existing inputs might be dual purposed and accessed by gcode from PC software (such as a hacked version of Pronterface) when the corresponding feature (say bed heater) is not immediately in use?

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Re: How to add/repurpose hardware inputs to Solidoodle?

It does, they're in that 2x6 header. One thing I wanted to add is a switch that pauses the print in the filament runs out/breaks.

You've gotta mod the firmware to do whatever you like! RH supports a sanguinololu-requested pause command.

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Re: How to add/repurpose hardware inputs to Solidoodle?

Here is one thing you can use, at least for outputs-

M42 in Marlin/Sprinter
Example: M42 P7 S255
M42 switches a general purpose I/O pin.

Also for Z probe-

G29-G32: Bed probing
G29 Detailed Z-Probe
probes the bed at 3 points.
G30 Single Z Probe
probes bed at current XY location.
G31 Report Current Probe status
reports whether Z probe is triggered.
G32 Probe Z and calibrate with FPU
probes the bed at 3 points and updates transformation matrix for bed leveling compensation.

Someone at the Makergear google group has worked with this, as well as Matter Hackers.  With a RAMPS you can use an unused endstop, with Sanguinololu you could use an endstop wired in with the Z stop.

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Re: How to add/repurpose hardware inputs to Solidoodle?

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Re: How to add/repurpose hardware inputs to Solidoodle?

Hmmm... think I could print an apple???

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Re: How to add/repurpose hardware inputs to Solidoodle?

?? what we need to do a probe to work with a g32 command? ?

if the code is already in marlin firmware, its a way to explore...

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Re: How to add/repurpose hardware inputs to Solidoodle?

IanJohnson wrote:

...with Sanguinololu you could use an endstop wired in with the Z stop.

I suppose I can just try this when I get home, but what happens if either endstop switch is suddenly engaged during a print? 

Once when my filament got tangled, I came back to a bunch of "y-endstop" error messages in the log, and it seemed to have aborted the print, or perhaps just the layer, but I wasn't there so I can't be sure which.  If so, I could just wire an abort switch in parallel with with the y-endstop switch and not have to change any software at all for the auto-abort idea.  If it only aborts the layer, I'd need to latch it somehow.  But what is the expected behavior for all of the endstop switches?  Can the current state of any of them be read with a gcode command (ala G31)?

And regarding the Z-probe commands, are all of these implemented in the SD firmware?  I could not find usage examples for them.  I'm curious if "bed-leveling compensation" already exists, and if so, what 3 points the firmware is set to use.

Matterhackers shows some nice automatic bed leveling that we could do as well, but it looks like they had to minorly tweak their firmware:

https://www.matterhackers.com/news/auto … ion-update