ARM port signal travelling

Development Boards MicroMod
1

Hi to all!

I wish to use ARM to pulse & direct the servo motor through a servo driver which is at long distance from the ARm controller.

I have doubt that the signal may get weak .

Any technique or interpreter circuit i should use to confirm the signal strength?

Thanks & regards.

2

How long ? you could use a RS422/485 driver/receiver as example.

3

It may be more than 4-5 meter.

is there any other easy way to transmit PULSE & direction signal to the Servo driver?

Regards!

4

A cheap RS485 driver can send logical signals over several hundred meters (depending on speed) using normal twisted pairs, one pair per signal.

It is also very reliable because it uses a differential signal.

5

Pls let me have more specific idea on how to use 485 standard to send pulse and direction to the target Servo driver.

If i need to send Direction and Pulse, then does i have to use two MAX485 to transmit signals?

Regards!

6

How many logical signals you need to send over distance ? there are ICs with multiple drivers/receivers so you will, most likely, just need one (multiple driver) IC on the micro controller side and one (multiple receiver) IC on the servo side.

As example the MAX3044 is a quad driver, MAX3095 is a quad receiver.

The selection of the right device depends on your needs, you must define:

  • Drivers/receivers number.

  • Speed

  • Voltage (5V or 3.3V ?)

  • Package (PTH or SMD ?)

You may select the right one here:

http://para.maxim-ic.com/cache/en/results/5023.html

Using a driver/receiver is very simple.

[ARM side]Logic level signal → RS422 Driver → (T)Twisted pair(T) → RS422 Receiver → Logic level signal[Servo side]

Sorry I can’t draw it better than that :slight_smile:

Note that the line should have termination resistors on both ends (T), you just need to read the datasheets, it is really simple.

7

Hi !

Thanks 4 the informative response!

As far as i got from this discussion:

if i send HIGH level on x’mit side(ARm side) , i will recieve HIGH pulse on reciever side(servo side).

I need to send two signals pulse and direction, so i need two pair of diver(one for each signal to be transmitted).

Is it right perception? If not pls correct me.

Thanks once again!

And also let me know if there is other simple way for long distance x’mission.

Regards!

8

Correct, you have exactly the same logic levels on the receiver except for some the delay (negligible in your application).

9

Thank you very much for your kind effort.

I will try it soon and let you know how it work for me.

Upto that pls let me have other simpler ideas if any.

Bye…

Regards!