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Gordie
Here is the site with schematics and more: [users.skynet.be]
Here is the schematic of Traditional, which I will buy: [users.skynet.be]
So, dear masters, which components do you suggest to change/remove to give it compatibilty to the RAMPS-FD? :)
I choose this Toshiba component because I was looking for a good Ampere driver, I think that this step driver is good for parallel wiring the step motors as it give up to 4A. Mine RepStrap has dual step motors system on the Z and X axes, so I can save one or two step driver outputs on the controller board. My plan was using the RUMBA or RAMPS and I didn't think about 3.3v when I saw the RAMPS-FD. That's the reason I asked my first question. Thanks for your good work on RAMPS-FD!
Ok, that is useful info. I will order one of the boards for testing.
One issue that I nearly mentioned but didn't was the question of opto-couplers. It seems on the skynet boards, they run off 5V which is provided externally. The optos would sink about 12mA each at 5V, or about 7.5ma at 3.3V which is a bit on the high side for the Due.
The optos also add a small extra delay of 1-2us, which may need to be accounted for.
So I think there is a definite need for a header module with level converter and pulse stretcher. I would like to use the standard pMinMo 10 pin connector, but it takes up a lot of space, so might be tricky. A possibility is to use the 4 pin motor connector for enable/step/dir/gnd, and hope that no one will try to plug an external driver into a Pololu motor output.
Here is a pic showing the concept anyway.
[attachment 25586 stepper-header2.png]
The two pin header is need to get 5V to the header board if the external driver does not provide 5V (seems to be an optional feature).