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Electronics => Electronics => Topic started by: ahtam on April 19, 2009, 01:27:42 AM

Title: computer controlling using ethernet? usb? vga?
Post by: ahtam on April 19, 2009, 01:27:42 AM
Hi,
I'm planning to make a computer based robot where a laptop is used in place of a microcontroller....
but....
can i control a dc motor circuit using ethernet cable? a usb port? a vga port?
how?
any help would be MUCH appreciated.
thank you
Title: Re: computer controlling using ethernet? usb? vga?
Post by: SmAsH on April 19, 2009, 01:33:44 AM
you can do it but i think you would need a servo controller and motor driver. im not too sure on how you would do it, look up airman00's butler robot as he uses a laptop to control his motors and they're dc. http://www.narobo.com/robots/ButlerRobot/butler_robot.html (http://www.narobo.com/robots/ButlerRobot/butler_robot.html) and he has a tutorial for it!
Title: Re: computer controlling using ethernet? usb? vga?
Post by: ahtam on April 19, 2009, 02:02:26 AM
the thing is, i live very far from US and i'm afraid i won't find those robot parts so is it possible to control usb without usb interface or using vga or ethernet cable?
thanks a lot for your quick reply
Title: Re: computer controlling using ethernet? usb? vga?
Post by: SmAsH on April 19, 2009, 02:20:18 AM
even if you do live far from the us many places have world wide shipping. you may be able to make your own that gets controlled by serial or parallel ports but im not too sure about vga or Ethernet, although there are Ethernet shields for arduino...
check out some of these http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=ethernet&x=0&y=0&search_section=products (http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=ethernet&x=0&y=0&search_section=products)
Title: Re: computer controlling using ethernet? usb? vga?
Post by: lanamor on April 19, 2009, 09:47:54 AM
You need some hardware between your computer and motors/servos. The three ways best ways  to communicate from a computer are USB, serial, and Ethernet. There are a ton of project boards out there. Youshould take some time to search the web.

Take a look at www.sparkfun.com (http://).

Also understand that your question does not have a simple answer because there are many ways to accomplish you task. However,you seem to be missing some prerequisite knowledge so many direct answers might be over your head. Also, VGA is an interface for a visual display so you can't use it to control anything. 
Title: Re: computer controlling using ethernet? usb? vga?
Post by: GearMotion on April 19, 2009, 10:00:36 AM
Controlling a robot via a laptop - consider RobotBASIC + USB U401. http://circuitgizmos.com/wordpress/?p=225 (http://circuitgizmos.com/wordpress/?p=225)
Title: Re: computer controlling using ethernet? usb? vga?
Post by: Soeren on April 19, 2009, 05:06:04 PM
Hi,

can i control a dc motor circuit using ethernet cable? a usb port? a vga port?
Has the laptop got any other ports?
You'd find it easier to use a parallel port (printer port) or a serial port.

The VGA port is out of the question unless you want to totally rewrite the firmware of the laptop, the Ethernet has got almost the same limitations and USB have only got 2 lines that is controlable (and controlling them for logic needs low level code (i.e. Ring 0 code), so is not for those having to ask.

Even with a parallel port you will need buffers, but a single transistor and a couple of resistors will do for each line.
Title: Re: computer controlling using ethernet? usb? vga?
Post by: AppleGuy on April 29, 2009, 07:30:34 PM
Try this:

It works over Ethernet and has Add-On cards for encoders and stuff.

http://www.robotics-redefined.com/index.php?main_page=product_info&cPath=28_30&products_id=62 (http://www.robotics-redefined.com/index.php?main_page=product_info&cPath=28_30&products_id=62)
Title: Re: computer controlling using ethernet? usb? vga?
Post by: hazzer123 on April 30, 2009, 03:20:03 AM
In order to get information about a screen (eg refresh rates and resolution) the VGA port has a basic I2C interface. You could try to use this!

Here is a great page about it - http://www.paintyourdragon.com/uc/i2c/index.html (http://www.paintyourdragon.com/uc/i2c/index.html)

EDIT: oh you don't want a microcontroller... so i guess an I2C motor driver is out of the question?