Sanity Check(list).. Stepper Motors etc

Greetings All,

I spent some time playing with the EIBotBoard, the Eggbot project, and then some creative Stepper Motoring things, and I want to try to build something bigger… So, my next project also calls for 2 stepper motors and later on 2 (or 3) switches, but I want to have a bit more control over the system from a programming perspective.

After some searching on the site, I think the Due is going to be the board I want to use as the microprocessor. Assuming that, I have some base questions, since I’m new to the whole concept. A few pages in, I saw that there is a stepper motor driver here on Sparkfun that controls a stepper motor (Easy Driver: https://www.sparkfun.com/products/10267? )that plugs into the Arduino Due. Which brings up the first question, with the Due, how many things can I connect to it? Really, I am choosing it because of the USB interface. That is a must for me. Would I be able to control / read input on 3 switches, and a 2 stepper motors?

I had read where Skye/filfreak was going to do something on his blog about a write up, but I haven’t seen it yet… so, I’m throwing myself on combined internal knowledge of this board to see if I can get some initial guidance. I think this is within my capabilities to hack together, but really, it’s another lesson for me, and it helps to have a conversation/starting place to begin reading from. In Recap…

Am I doing the right thing by using the Due Board?

Will it handle the 2 Easy Driver Boards (Motors are 1a 1.8 2.5v? 6 wire Stepper motors - totally within operating params)

If I decide to go a little further with it, would I be able to integrate 3 more switches on the same board?

Thanks for your insights in advance.

~D

DRegalia:
Greetings All,

I spent some time playing with the EIBotBoard, the Eggbot project, and then some creative Stepper Motoring things, and I want to try to build something bigger… So, my next project also calls for 2 stepper motors and later on 2 (or 3) switches, but I want to have a bit more control over the system from a programming perspective.

After some searching on the site, I think the Due is going to be the board I want to use as the microprocessor. Assuming that, I have some base questions, since I’m new to the whole concept. A few pages in, I saw that there is a stepper motor driver here on Sparkfun that controls a stepper motor (Easy Driver: https://www.sparkfun.com/products/10267? )that plugs into the Arduino Due. Which brings up the first question, with the Due, how many things can I connect to it? Really, I am choosing it because of the USB interface. That is a must for me. Would I be able to control / read input on 3 switches, and a 2 stepper motors?

Well, there’s a few things you need to look at. That driver board has a max of 750mA per phase. Your motor, as you stated, is rated for 1A, which means it might work, but you won’t see the full capabilities of the motor. Yes you can have 3 switches hooked up at the same time.

Am I doing the right thing by using the Due Board?

Yes. But there is another issue, the Due is still very new and there isn’t any libraries out yet pertaining to motors. But if your confident in coding with C++, then this won’t be an issue.

Will it handle the 2 Easy Driver Boards (Motors are 1a 1.8 2.5v? 6 wire Stepper motors - totally within operating params)

It can handle more than 2 boards if you program them right. Another thing to look at is the Due only outputs 3.3v. Now the Driver board can be configured to work off 3.3v, but a soldering iron would be needed.

The answer to your question is yes. The EasyDriver will run your motor, but not quite at full speed or torque (which may likely be just fine). Another alternative is the BED (Big Easy Driver - also designed by me and sold by SparkFun) which can do over an amp per phase. (UP to about 1.4A/phase)

Both the BED and ED will work fine, under normal circumstances, with 3.3V input levels, even without switching them over to 3.3V logic power (using the soldering blob mentioned by codlink).

The Due has plenty of power (CPU power) to run two steppers -actually, it can do way more than that. However, it is very, very new.

Another alternative that is cheaper than a normal Arduino but far more powerful is the chipKIT UNO32 or my ‘clone’ called Fubarino SD. They’re PIC32 boards that run at 80MHz and you can run the fantastic AccelStepper library on them and get much greater performance on many more steppers than with a normal Arduino. Just a thought.

There will also be an Arduino compatible version of the EiBotBoard coming out this year that will be much cheaper than the existing EiBotBoard.

*Brian

Well, it’s a good thing I stopped here to get advice first.

So, First: Codlink - Thanks for the heads up on the board. I would rather I had more power than not, just incase I need a bigger motor, or something, I’d hate to build to the minimum spec. I’ll look at some of the other controller boards then.

Brian - I’m not able to find the Fubar-ino SD anywhere on the site (could you pass me a link?). Whats the difference between the bi-polar step motor controllers and say a 2 phase, or 4 phase. Can they all be controlled from the same board?

With regards to the Arduino UNO REV3 compatible boards, can I use the same development language with them? I want to do all my coding from VB.NET and control it all thru windows.

Thanks again,

~D

D,

It’s strange that you couldn’t find the Fubarino - the website is http://fubarino.org/ and if you do a search for Fubarino in google you’ll also see the link to where SeeedStudio is selling them.

The differences between bi-polar steppers and uni-polar steppers (2-phase or 4-phase) are also listed on a number of other websites - for example http://en.wikipedia.org/wiki/Stepper_motor.

There are some boards (like the AdaFruit Motor Driver shield) that can be set up to drive either bipolar or unipolar motors, but most boards (like EasyDriver, Big EasyDriver, and EiBotBoard) can only do one or the other (bi-polar for the three just mentioned).

*Brian