1 Topic by 2n2r5

  • 2n2r5
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  • From: Frederick, MD
  • Registered: 2013-05-09
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Topic: Upgraded Electronics Advice - RAMPS 1.4, DRV8825 Step Drivers

I am just upgraded to a mega 2560 with ramps 1.4. I had one A4988 go bad on me and I am now on a spare. I have 3 more but they are on my sanguinololu.

I was looking to switching to http://www.pololu.com/catalog/product/2132 DRV8825 stepper drivers. They can do 1/32 micro stepping and depending which version can handle steppers that draw up to 2.2A.

Has anyone used these? It looks like they are a drop in replacement for the A4988 on a ramps board. Is that right? Is having 2x the X-Y resolution helpful or just unnecessary? I would think that ~88 steps per MM is more accurate than the stretch of the belt.

My VRef Settings should be(?):
X axis: .555v
Y axis: .65v
Z axis: .625v
Extruder: 0.24v


Also, has anyone upgraded to the most current revision of Marlin that is using the RAMPS 1.4. I finally have mine setup correctly I believe but it would be nice to compare pin.h and configuration.h with someone else.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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2 Reply by lawsy

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Re: Upgraded Electronics Advice - RAMPS 1.4, DRV8825 Step Drivers

I am using the newest version of the Marlin from my github with Ramps 1.4.

Attached is my configuration.h

I don't believe I changed pins.h from what is on github.

Please note that I have some custom tweaks like different PID settings, min and max temps, z steps per mm, etc.

Post's attachments

Configuration.h 18.79 kb, 29 downloads since 2013-06-14 

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3 Reply by adrian

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Re: Upgraded Electronics Advice - RAMPS 1.4, DRV8825 Step Drivers

My repository of the new Beta firmware is over at https://github.com/ozadr1an/Solidoodle-Marlin_v1 , with the main stuff already pulled into Lawsy's as well.

BTW.. there is no actual reference to RAMPS 1.4, as it is functionally identical to RAMPS 1.3 , so thats what you need to look out for in the firmware.

The newer firmware also has all the support for the Full Graphics LCD... you will need the u8glib seperately though (refer to the source code)

4 Reply by 2n2r5 (edited by 2n2r5 2013-06-14 13:52:36)

  • 2n2r5
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Re: Upgraded Electronics Advice - RAMPS 1.4, DRV8825 Step Drivers

adrian wrote:

My repository of the new Beta firmware is over at https://github.com/ozadr1an/Solidoodle-Marlin_v1 , with the main stuff already pulled into Lawsy's as well.

BTW.. there is no actual reference to RAMPS 1.4, as it is functionally identical to RAMPS 1.3 , so thats what you need to look out for in the firmware.

The newer firmware also has all the support for the Full Graphics LCD... you will need the u8glib seperately though (refer to the source code)

I just got the smart reprap discount LCD or whatever they call it. I think the same one as you but I was looking into the full graphic one. I think I might need to throttle back my spending on this printer. I am pretty sure I more than doubled the original cost of the printer on stuff just to play around with. lol

Thanks for posting your software repository. I got everything working with my fw tonight. I think I am going to add some code for a few other switches. I was thinking on for a door switch that would act like a washing machine. When the door opens , the print pauses. It would be a little bit of a safety feature at least. It could probably use the same code that you put in fie the filament alarm.

Lawsy,

Thanks you the config. I saw what I did wrong almost immediately. Some times it takes a small reminder to put me back on track.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

2n2r5's Website