stepper controller features

[smarbaga]

i have designed this controller.
would some one have a peek at it and
tell me if there are any necessary features
i missed, before i build it
thank you all
**** attached xyz_dsn.pdf ****
hummm... don't see how to attach .....
i'll be back

[lerman]

I would probably try to get rid of the pots. If the circuit design really required them, I might use digital pots.

Do you really need both hard limit switches and optical limit switches? (For my Bridgeport clone, I'm going with mechanical limit switches and TBD home switches). It appears that your reasoning is to have the hard limit switches turn off the power and the optical limit switches interface with the micro. But if the code is correct, you should never hit the hard limits -- or any limits for that matter.

Ken

[smarbaga]

Mr. Lerman
thank you for sharing your experience with me. ( your advice )
my acceleration/ de excelleration voltage ramp is controlled with a digital pot
the rate of accel/de-excell would be adjusted with pcb trim pots ( if i ever change tools from light to heavy it may take a longer time to get over the extra weight inertia
i guess u r right on the limits, mechanical ones would prob. be just fine.
i think i will still have a optical home switch ( i guess i should have said position)
the hard limit switches ground a mosfet gate in the 5v regulator, which shuts down the micro and other regulators leaving zero volts to the phases.
again thanks a lot for your valued advice
sincerly smarbaga