Comments on: usbmot

By: Andreas Goelzer

Andreas Goelzer — Sun, 20 Nov 2011 23:04:48 +0000

jesus: I wasn’t using an ide, just text editors. Yes, it would be the command prompt in windows, but that requires some setup(as make is still quite unix-centric).
Compiling my code in codevisionavr should be easy, but unfortunately it uses an old version of obdev’s vusb that might be more difficult to compile. You might have more success replacing it with a newer vusb version and adjusting my code.

By: jesus

jesus — Thu, 10 Nov 2011 03:53:14 +0000

Hi Andreas your project its great, sorry about my english I am from Mexico, I have some doubts the compiling process you comment that we have to adjust the uC type and programmer and then type “make hex” or “make flash”, but here is my problem that command where do i have to type it, in the windows command prompt? or where… I have an AVR programmer based on the USBASP so it’s really simple and I don’t know where exactly to type those commands because when i have to program my uC I do it via command prompt on windows , also I’m using Codevision for compiling, what program did you use AVR studio?, I hope you can clarify my doubts.

By: Enda Asenjo

Enda Asenjo — Tue, 03 May 2011 16:03:48 +0000

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By: Andreas Goelzer

Andreas Goelzer — Sat, 02 Apr 2011 05:32:50 +0000

Sorry for answering so late. I’ll anwer anyway, for future readers…

laosoi:

That is quite hopeless, this is for a small motor (500 mA max.). You’ll need some big mosfets for 25 A, and careful planning.

Alec:

One (small) bipolar stepper motor might work with this if you do some firmware rewrite. If you want 3 stepper motors you’d need 3 usbmot-boards, or design something else, I have something like that flying around here.
If you want to build a cnc mill or some other 3-axes device, i’d advice against it. The l293d is too weak for serious stepper motors, and you can get more power out of stepper motors with constant current instead of constant voltage.

Tobi:

sorry for not answering to your first post. Haven’t used this for a while, this firmware-usb with its inherent lack of a working communicating device class (cdc) just was too much hassle.

The “usbmot” folder inside the archive is the firmware, the “qusbmot” folder is the host software.

Yes, typing means on the console, but the article was written with linux in mind. in windows, after compiling just click on the qusbmot.exe.

However i do not know how difficult it is to compile the host application in windows, the qt part is more or less trivial with the qt sdk (open the .pro file, hit run), but the libusb part needs some work. There is a mingw-version, so it might be doable or even simple for an experienced windows coder, but I’ve never used it in windows.

If you plan on using java as host software, you might want to consider rewriting the firmware with the almost-working firmware-cdc (*) or using something like the ft232rl as i did with my usbservo project.

(*) firmware usb allows only low-speed devices, and the usb standard does not allow cdc for low-speed devices. obdev’s v-usb implements it anyway, it works with some operating systems, your mileage may vary. The big advantage of cdc is that the software on the pc only needs to open a serial port, possible in almost all programming languages without libraries.

By: tobi

tobi — Fri, 01 Apr 2011 16:21:11 +0000

hi this is exactly what i was looking for..but how could i bring the firmware and host software to pc and to the atmega8?

im am new at ansi c.

at the moment i compile my c code with avr studio 4 and bring it on the atmega via yaap

but i dont know which file from the software.jar i have to open to get the gui on pc and i dont know which file i should compile to bring it on the atmega8.

in ur descritpion u say “Type” do u mean type in the DOS-console of the pc?

By: Alec

Alec — Tue, 23 Nov 2010 11:00:00 +0000

Is it possible make controler for 3 step motors based on atmega8 + L293D+USB ?

By: laosoi

laosoi — Fri, 23 Apr 2010 15:42:28 +0000

Hello Andreas Goelzer,
Thanks for your project!
Please tell me how to control 25A, 12V, 3800rpm brushless motor using this project?
Help me, i want to control high rpm motor using usb!
Many thanks

By: Alex

Alex — Sat, 27 Mar 2010 09:09:02 +0000

Nice job…

By: Andreas Goelzer

Andreas Goelzer — Sun, 28 Jun 2009 18:38:02 +0000

Thanks a lot, nice to hear it helps you

I don’t know how pyusb works, and this control-endpoint stuff is not exactly comfortable. But with vusb, options are limited. I’m planning to redo this with an at90usb162, that could then have a nice serial interface and work in more environments.

If you just want to control this device from python, you can have python call the commandline-program with os.system(“./usbmot-cmd write 1 2000″) or such stuff, but that’s more a hack than a real solution.

I hope you somehow get it working, good luck

By: paryl

paryl — Sun, 28 Jun 2009 18:00:08 +0000

Andreas, this is awesome stuff. Exactly what I’ve been looking for! I’ve got it working using your example programs, but what I really need is a python version.

Have you managed to control it using python? I’ve been trying for a few weeks now using pyusb, but nothing I do lets me communicate. I suspect it’s an issue with not knowing the proper endpoints, or something to do with the data I’m sending. I consistently get “error submitting URB: No such file or directory”.

I’d love some hints if you have any to give…