Arduino Due with RAMPS data needed

As I work through the software changes on a Delta printer that I am rebuilding, I am beginning to see the tail-lights of a memory & processing limit ahead. The problem that I have is that when I originally built my three printer I allowed space only for an Atmega and a RAMPS board and the ancillary wiring and connectors - with no (zero, zilch, nada) wiggleroom. Even the connectors have to be inserted in a particular sequence.
The obvious solution is to use an Arduino Due with a modified RAMPS to work at 3.3V but all I can find is some very early posts about trying to do this. Can anybody point me at a blog or buildlog with what needs doing and/or avoiding. Alternatively, is there a commercial board that fits in eeeeeexactly the same space as an Atmega/RAMPS combo.

Mike

I believe you're going to need to make more room to go 32bit.

Of the two 32bit I have:
RADDS which uses a Arduino Due is about 20mm wider to one side.
Duet 0.8.5 is just under 100mm x 123mm.

Neither Duet nor RADDS are an option and RAMPS-FD is even worse. Photo below shows one of the three printers - the other two are different but equally constricted.

As far as I can make out it should only be necessary to change the MOSFETs for ones that with work with 3.3V and find alternative pins for the SPI used on the SD card but what I was hoping for is some feedback from someone who had done this - or if they failed then why.

Mike

The Azteeg X5 is 100x56 (http://files.panucatt.com/datasheets/x5mini_wiring_v2.pdf - the V3 board may be slightly larger, due to the Ethernet connector). I can't find the dimensions for RAMPS, but the Arduino Mega 2560 board looks like 102x53. So you might get away with it.

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See my blog at [moosteria.blogspot.com].

see thread [forums.reprap.org]

Most if it is summarized here in Russian (google translate does a good job on it) [3dtoday.ru]

There is also the "SMART RAMPS" [reprap.org]
I have no experience of this, but is meant to work on due out of the box.

Thanks Dust and animoose. Having spent a couple of hours reading up on the potential problems it seems that none are insurmountable - however they are problematic enough that I think I will let idleness, cowardice, procrastination, hope and any other excuses rule and keep to the Mega2560 for the moment. Maybe on the next printer.

Mike

Quote
Dust
There is also the "SMART RAMPS" [reprap.org]
I have no experience of this, but is meant to work on due out of the box.

No way will it work well on 3.3V - according to the schematic, it uses the same poorly-chosen (by modern standards) mosfet as old RAMPS.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

@dc42

The board they sell doesn't match the documentation of the pcb lay out or the circuit diagram...
No idea what they actually provide.

I agree documentation implies its using same ramps MOSFETs, which would be a bad thing to do, but its also not a problem to replace them.

Let me get the dimensions on my Replicape when I get home, with the connectors bent up or new ones put on it might just squeeze in there. I cannot find any dimensions online for the board but its basically a cape stuck on top of a beagle bone black, unfortunately it is a little bit wider then the BBB below it.

It looks as though I have changed my mind once again: I believe that i do need to go the 32 bit route - I have just completely rebuild my Rostock printer and have used 0.9 degree steppers. The increased workload on the Arduino Mega2560 causes a distinct stutter when the effector is moving fast - with 1.8 degree steppers this was just a melodious arpeggio.

zerodameaon, did you get the dimensions of the Replicape? What software does it use to drive the steppers and is i compatible with the common 4X20 displays?

Thanks for any info,

Mike.

Replicape B3 is about 4.2 by 2.7 inch, a little larger than RAMPS 1.4, plus the connectors appear to be right-angle rather than vertical, but they could be replaced. Replicape runs Linux firmware "Redeem", and you would need to pre-order Replicape.

I think your easiest route would be to get Smart Ramps and replace the MOSFETS, and maybe fuses while you are about it. Smart Ramps has different Aux connectors, so you need a different display board or rewire for your existing display.

Just for fun, I am designing a board which is a blend of RAMPS 1.4.2 and Smart Ramps, I might call it "RAMPS-FD Lite" or something.

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It would have been really good if somebody had bought out a 5V 32 bit version of the Arduino boards. It looks like the 32 bit 5V ARM mcus are only just starting to appear and most of those are ARM M0s. NXP does make the KinesisKE1xF series which is an ARM M4 but I believe that it only came out this year.

I guess Smart Ramps it must be

Mike

So many peripheral chips are 3.3V only these days - for example, the chips that the Duet WiFi uses to read thermocouples and PT100 temp sensors - that I don't see the point of a 5V ARM processor. About the only advantage I can see for a 5V processor is that it can drive high power mosfets directly.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks Bobc, it's been a busy weekend. As for the connectors you can likely bend them up or better just replace them. Though yeah it is now on backorder but it looks like he gets some in every few weeks(I think). It runs Kamikaze(debian linux) on a beaglebone black and the replicape is a cape that goes on top and it runs redeem which you can configure via octoprint or SSH into the board and edit the text files.

Quote
dc42
So many peripheral chips are 3.3V only these days - for example, the chips that the Duet WiFi uses to read thermocouples and PT100 temp sensors - that I don't see the point of a 5V ARM processor. About the only advantage I can see for a 5V processor is that it can drive high power mosfets directly.

I think the biggy is noise margin particularly with industrial control. Going from the advertising bumpf from Cyrus, Fujitsu, NXP and even AVR all of whom have 5V ARM MCUs there are other areas of the 5V technology which lead to greater reliability and robustness as well.

Mike