Stepper motor driver board

Can anyone tell me if the stepper motor driver board v1.1 be used without the Arduino Diecimila board.

That is really simple:

_driver_ boards are for the Arduino
_controller_ boards are for the PIC

So the answer is yes.

--Blerik

Cool Thanks.
Now can the stepper motor driver boards be used as stand alones and use a 25 pin
connector to communicate to them?

yes, theoretically. you'll want to get a parallel port breakout board that has opto isolation chips on it, but the stepper *driver* boards use the industry standard step/direction interface.

this board looks promising: [www.embeddedtronics.com]

if you do so, please let us know. i'd love to get that route documented somehow as its pretty rad.

Opto isolation is only a safety measure if all is working OK it's not required it gives another level of protection between the Stepper voltages and the computer.

---

Ian
[www.bitsfrombytes.com]

its not required, but i certainly dont want someone to fry their computer on my recommendation.

get one with opto isolation if you value your computer.

Opto isolators are not just for safety. The main reason is to separate the logic ground from the power ground to prevent ground bounce adding noise to the logic signal.

See [hydraraptor.blogspot.com] for an example of how to prevent motor currents flowing in your logic ground.

RepRap seems to ignore this issue but I suspect people will have problems unless they keep all the ground wires short and thick.

---

[www.hydraraptor.blogspot.com]

Audio guys know lots about ground bounce and related issues.

I find the easiest way is star earthing - each ground from each device is wired separately to one point, even if this means you have 5 or more ground wires running side by side.

At this point, you have a big power filter, usually a big electrolytic capacitor with a few ceramics in parallel for high frequency response, and a choke from the supply, as well as a choke on each power lead that is expected to carry noise.

Make sure that each piece of equipment is only grounded once - loops act like a big antenna and inject all sorts of nasties into your ground. If the board has several inputs each with its own ground, a 5-20 ohm resistor in series with the signal ground can diminish loop-related issues.

If you're really paranoid about grounding issues, run differential signals and have loop breakers at every input.

Also remember that noise can be capacitively coupled between nearby pieces of equipment, as well as radiated from wires. A small (10nF) ceramic capacitor across the coils of your motors, and one from each lead to the motor case as close as physically possible to the motor itself helps with radiated noise, and a 10-100nF ceramic and a 10-100uF electrolytic at the power input of each board will help too (if the board doesn't already have these). *Grounded* pieces of metal between noisy boards act as shields. However, if you don't ground them, they become passive radiators instead of shields and can actually spread the noise further than it would otherwise go.