Ideas for DIY Stepper Driver

[epineh]

I'm just after some idea's on generic requirements for a stepper controller board. I have to say that I went to start a new thread and noticed Phil's thread on pretty much exactly what I had in mind - AVR Microcontroller based design, with most of the work done in software/firmware. Didn't want to hi-jack Phil's thread so started this one, besides my project will most likely take a LONG time to get going.

While I don't want to re-invent the wheel, I have some time on my hands after the kids go to sleep to tinker but the noise has to be kept to a min. Have played around a bit with AVR's previously but nothing serious.

What I intend to do (try) is take a modular approach, have easily changeable configurations to allow for most (hobby level) motor applications. Different output stages for different size/current/# of wires. Use commercially available H-bridges, try to keep external component count down as much as possible, build solid driver bases and update features in software.

My thoughts so far are :

4 Axis as standard with expansion capabilities (thinking modular here)
Constant current power supply
Separate gate driver boards (to allow simple upgrade/repairs)
Separate Logic board with dip switches to configure operation
Provision for simple flash upgrading of firmware in circuit
Test points on PCB (s)
Utilize commonly available parts

Physical setup will be similiar to a PC, one mainbord with various boards plugging in either directly or via cabling, upgrading/repairing consists of removing unwanted/non-working card and slotting in new card (s)

I guess what I am after is suggestions on what is needed to cover MOST hobby applications. I don't intend to make these to sell or compete with what is already out there, just something to do and maybe help a few in the community (CNC community that is)

Any input is appreciated (no pun intended )

Cheers in advance.

Russell.

[pminmo]

Hi Russell,
Sounds interesting, if I can be of any help let me know. If I understand your approach, your thinking of putting the micro(s) on the mainboard and the plug in's are just the output stage?

[Kipper]

I'm not sure I fully understand what you're intending to do! however the modular approach sounds interesting...Will it be a eurocard type where everything goes onto the backplane or am I way off? oh and Phil the boards arrived really fast and in excellent condition (meant to say thank you but it slipped my mind till I saw your name mentioned :beer: sorry for the threadjack epineh)

[epineh]

Hi Phil, I just thought that if the parts that will need to be different for different users could be seperate cards - output stage, power supplies mainly then it could be easily configured for different motors as needed, smaller stages for the 100oz in size, getting larger for the bigger motors and possibly associated higher voltages, hopefully all combinations utilizing the same micro and program, the dip switches were simply to let the micro know what is going on - unipolar, bipolar, microstepping, 4,6,8 wire yadda yadda...

Actually Phil if you could point me to info on the basic stuff, step pulse width, standard acceptable frequencies an so on, books or links, whatever you recommend, I am starting with the overview and getting to the nitty gritty as needed.

I think I should point out I am by no means an expert on any of this, just looks like a fun project.

I guess the idea is that someone can start off with a cheap driver setup (as you mentioned around $50.00 bucks worth of parts) and once that is going can upgrade to a set of 5000 oz/in motors, and only need to unplug their old output stage and plug in the new one (and possibly beef up the power supply a bit )

Kipper I'm not sure what you mean by eurocard, but the idea is to use whatever is easily obtained, edge "simmstick" type cards would look cool, but in the end of the day ribbon cables might be simpler.

I guess all I need at the moment is to know what a driver "Needs" and what would be "nice" to have on board - pun intended.

Ordering an STK 500 soon so that should keep me busy for a while.

Russell.

[bunalmis]

Interesting coincidence.

I begin this type design.

[epineh]

Nice job, looks similiar to what I had in mind, got any specs ?

I am a LONG way away from producing anything, nice to see I'm not alone in thinking of a modular build.

Looked at your website, but couldn't understand the lingo, I can only understand English (Australian English at that!) pictures look good though.

Russell.

[bunalmis]

This is general purpose driver.

It is bipolar microstepper and also unipolar microstepper and also closed loop step motor driver and also DC servo driver.

Wide range current and voltage applications, simple replecement of power MOS, simple upgrating firmware are some properties.

But not finished yet. I work to adding for new features.

I want to add small CPLD and so it will drive the BLDC servo.

[epineh]

Looks like you have it covered, have you had the drivers turning any motors yet?

Again, nice work.

Russell.

[cbcb128]

pcb?sch?

[Cooper]

Originally Posted by cbcb128 pcb?sch?

It is a commercial project. bunalmis sells them

Cooper

[tivoidethuong]

Originally Posted by bunalmis Interesting coincidence. I begin this type design.

look nice driver, what is mcu u use?

[max_imum2000]

bunlamis
what are the specs on these drivers
and how much please ?
thanks