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Do you think this circuit will work? Answered

Ok, for a robot I'm designing, I need to control some USB motors via software. I want to do this without using a microcontroller, as the computer should already have all the fundamentals. I have designed a simple circuit and attached an image below, do you think this will work? What I want to do is send a signal to the motor, that, as long as it is on, will keep the motor on.


You don't know how to control the USB data channels. Ask about that first.

You will have to use some kind of microcontroller and write software for it. Maybe you've got an old serial-port? But you still need the machine's microprocessors and you still need to program something.


Also, I'm ok with making a simple circuit, in fact I expect it. But it is no longer classified as simple when it contains an ic, or has too many components, at least according to me.

USB -- as the "S" states -- is a serial connection. And, in fact, it's a full communications prototcol rather than just being a simple serial port; that's how you're able to connect multiple devices to a single USB port. To interface to USB, you *MUST* either use someone's off-the-shelf solution (which will contain a simple microcontroller) or provide and program your own.

Suggestion: Buy a USB-attached parallel port. That should be cheap, and they will act more the way you want this to (letting you turn a set of bits on and off.) It will still be up to you to write the appropriate PC software to send the relevant bytes to turn the parallel lines on and off.

Or you could get a USB-attached serial port and (ab)use some of the status/control lines, which can also be toggled on and off by appropriate software.

Or you could use the PC's built-in serial and/or parallel ports, if it has one or both of those.

. +1. Texas Instrument is selling USB-driven microcontroller kits for as little as 4.30 USD for a MSP430 LaunchPad. Other uC manufacturers have similar deals.

ST too, for arm Cortex boards.
So much stuff, so cheap, its silly.


The idea behind it is that a computer should already be able to control motors as-is, even if custom software would have to be written for it. You are right, however, that I know relatively little about USB data channels, where would you reccommended I look?

Well people do sometimes use micro controllers via USB- look-up Arduinio.


Not the tiniest hope in hell.

Why do people say such things? Wouldn't hope be generated I heaven, therefore heaven being where you would have the most hope?

Start out by understanding what USB IS. Then realise what a silly question it is. In fact, if you'd already had a cursory look at USB, you'd not look silly at all. ....

Nope, not a chance.
Why? Because USB doesn't work that way.

Could you be more specific on why USB doesn't work that way?