Linistepper - cheap unipolar microstepping driver

[pminmo]

James I don't have the PCB files on the Linistepper, I kinda thought they were on the website I listed, but after estreme's remark I went and looked, and all there is is a component layout.

I'm not of the mindset to "copy" a legitimate design. By that, something that isn't straight cookbook or application note. Throwing a couple of flip flops and exclusive or gates like in the discrete design is so textbook that's nbd. But throw in some embedded code that isn't a straight lift from an app note, even though it maybe published I don't do. Do you know the who the original designer was? I'd be willing to contact and see if we could work something out. My goal would be compatability with the other open source designs.

Phil

[James Newton]

My Bad. I ment to say that posix has files. He must, because he didn't order a PCB from me and he made a linistepper! I don't know why I said pimo... Senior moment I guess. Sorry.

Roman Black designed the Linistepper and makes the PCBs and Kits that I sell.

[posix]

Hello there fellow cnc peoples.

I didn't buy a linistepper but instead have designed my own linistepper layout. It's single-sided as opposed to double-sided which the original one is. The board size is roughly 3.3 inches by 2.4 inches and is probably a bit bigger compared to the original linistepper because I am using wago clamps instead of pin connectors. This board is for people who really really want to build it themselves (for whatever reason). Here is the pcb for it.

Please note that I will be reviewing the board as what I have made was slightly different to this. I wanted to re-shuffle the components around a bit to save some space but was rudely interrupted by a week-end away on the coast. You can build this and it should work fine just watch out for an odd trace being too close to a pad etc. I'll try and make something slightly better in the coming days.

[extreme]

Great

[DukerX]

I really loved the "Half step Full torque" paper, and think I'll try to use it whit some of my own stuff.
I'm using AVR µC to control some Sanyo STK6713 hybrid stepper drivers.
The reason I'm using these, is because I have a pile of them, scavenged from Panasonic and Minolta paper copying machines.
The STK6713 (and STK6712) are unipolar drivers whit 4 TTL inputs, and two separate pairs of chopped MOSFET output stages so that the current in each of the 2 coils can be controlled individually, through two separate comparator inputs.
This, I think would alow me to take the PWM out of the µC and by using 2 aditional I/O lines for each motor, I could do "Full torque half step".
To do more intricate things, like microstepping, I could use some more I/O lines and make a simple resistor DAC to set the chopper comparator input signal.

When I get home from work (!!) I'l get straight to it, and maybe I'll be able to present my findings later on today.

If you happen to have a STK6712 or STK6713 sitting on some old scavenged PCB's, or are just a general scavenger, and want to know more about what you've "caught", you might want to check out www.datasheetarchive.com

[posix]

James Newton are you still around? I have a question for you.

The linistepper is built, well 3 of 'em actually

But one is giving me trouble. You say in some of your documents not to leave inputs (mode and power inputs) floating. I noticed my power and mode jumpers fell out a few times while I was trying it one of these suckers. And since then it's been giving me problems.

Can you elaborate a bit on the "Don't leave inputs floating, either tie them to 5v or gnd". Why not? What happens when you leave them floating?

[James Newton]

posix, a "floating input" is bad for just about any controller. What it does is allow the input to change randomly and under some conditions, cycle back and forth rapidly. That can, under some, probably rare, conditions, cause damage to whatever the controller is controlling. In this case, that would be the power transistors.

In any case, when the board is acting up, the answer is good troubleshooting. Check the thread above and take the same readings you did before.

[tivoidethuong]

did you make Hex file for pic16f628A?

[ebe]

Hi guys!

I just found the linistepper site a few days ago. It's a great project. You have all my compliments. The site itself is a bit chaotic though. I've read thru it, but couldn't find which controler board you are using. I would much aprreciate some info on that. (schematics and PCB layouts of the controler board) Thanks in advance!

Eddie

[James Newton]

from the main linistepper page, click on "Open Source" to go directly to the open source files such as Posix's board layout and so on. That page is also linked from "the gallery" of users machines and from posix's coments on the main page.

(puts on sales hat)

I know that some people like to make thing all on thier own, but do keep in mind that you can't possibly make three PCB's for price we sell them or buy the parts for less money than we charge for the kit.

In any case, let us know how it goes!

[ebe]

Thanks James! I am considering buying the boards from you. I sure don't like fiddling about with hot irons and acid. Making them is my last choice. Do you ship to Serbia? Are there any other costs besides the 15$ for shipping?

[James Newton]

Nice review of the Linstepper at:
Product Review - Linistepper - Electronic Circuit BLOG

Great site BTW, if you haven't checked it out.