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Topic: How to send commands to motor controller down a 100ft wire (Read 596 times) previous topic - next topic

David82


If I was using one of these motor controllers which can accept all sorts of protocols for sending commands, what would be the best way send commands down a cat5 cable to it from a long distance like 100ft? It's not a wiring question but a question of which command protocol will still be interpretable by the controller 100ft down a wire. Or, which protocol could most easily be made to work that far.
http://www.pololu.com/catalog/category/96

Grumpy_Mike

For that distance I would use asynchronous serial RS-232.

David82

should I just use an arduino serial out to do that? Anything special needed for this scenario?

PeterH


should I just use an arduino serial out to do that? Anything special needed for this scenario?


You'd need an RS232 driver at each end.
I only provide help via the forum - please do not contact me for private consultancy.

David82


Grumpy_Mike


why can't the arduino do it by itself?

Because RS232 has voltages that are +12V and -12V, the arduino can only output 0V and +5V. It is the TTL option.

zoomkat

In the picture I see TTL on the board. For only 100' a servo control signal might work.
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

Grumpy_Mike


In the picture I see TTL on the board. For only 100' a servo control signal might work.

Yes especially if the TTL was driving an open collector transistor with a pull up to 12V or so. But he did ask what I would use and that is RS232.

zoomkat



In the picture I see TTL on the board. For only 100' a servo control signal might work.

Yes especially if the TTL was driving an open collector transistor with a pull up to 12V or so. But he did ask what I would use and that is RS232.


Sometimes it saves time and effort to provide options that the person may not be aware of.
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

Grumpy_Mike


Sometimes it saves time and effort to provide options that the person may not be aware of.

If I am asked what I would do then why should I reply with something I would not do. You have to admit that sending TTL down a 100' line is not a sure fire hit is it?

LarryD

You could use a current loop.
OR
Does anyone know if I2C would work?
The way you have it in your schematic isn't the same as how you have it wired up!

Grumpy_Mike

Quote
Does anyone know if I2C would work?

Yes ..... No

zoomkat



Sometimes it saves time and effort to provide options that the person may not be aware of.

If I am asked what I would do then why should I reply with something I would not do. You have to admit that sending TTL down a 100' line is not a sure fire hit is it?


Not a sure fire miss ether. You do what you, better or worse.  :)
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

cjdelphi

what if you buy a shielded network cable, you might get away with 5v logic


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