ethernet/rj45 to wireless (rf?)

Wireless & IoT
1

Hello everyone,

I have a Pan/Tilt camera head that has two RJ45/ethernet inputs (for each axis).

Its joystick controller has a single ethernet output and is powered by a 12v battery (I think it’s 12v).

[Battery] + [Joystick] —> RJ45 Cable <— [PT Head]

I wonder if there is a way to make the whole system wireless?

Is it possible to:

[Battery] + [Joystick] —> [RJ45 → Radio Transmitter] —> wireless <— [Radio Receiver ← RJ45] <— [PT Head] + [Battery]

Has anyone have any idea how to build the:

[RJ45 → Radio Transmitter]

and [Radio Receiver ← RJ45]?

Thanks and Best Regards,

Cedric

2

Are you sure the signals carried by the cables actually transmit like the ethernet standard? They may just be chosen to be convenient plugs in practise because of the locking mechanism. And a compact way to combine 8 wires into a single plug.

1 RJ45 plug for each motor doesn’t sound like it actually carries IP packets. Also, motors need significant current to run. How is that carried wirelessly? I think you should investigate more closely what sort of currents and signals these wires carry.

3

Hello,

There are two motors for each axis (4 motors in total), and each axis is given one rj45 line.

I don’t know what sort of signals they are sending, is there a way to find out?

Two two RJ45 cables go into a simple adapter that makes it 1 Rj45. (adapter = 2 female → 1 female)

this single RJ45 feeds power to the motor from the joystick/battery.

Here is the product:

http://www.kesslercrane.com/product-p/100117.htm

Thanks!

4

perhaps those RJ45 connectors are power and control and have nothing to do with Ethernet - but just use those connectors because they’re commonplace.

5

cygb:
Hello,

There are two motors for each axis (4 motors in total), and each axis is given one rj45 line.

I don’t know what sort of signals they are sending, is there a way to find out?

Two two RJ45 cables go into a simple adapter that makes it 1 Rj45. (adapter = 2 female → 1 female)

this single RJ45 feeds power to the motor from the joystick/battery.

Here is the product:

http://www.kesslercrane.com/product-p/100117.htm

Thanks!

Listed is in the specs of the product is the following line:

Cabling is CAT5 / CAT6 cable with RJ45 connectors (standard network cable). NO EXPENSIVE PROPRIETARY CABLES!!

The RJ45 style connection is used to cut cost. I do not see a ‘simple’ way to make this a wireless system.

6

Thanks for the input guys. It’s rather unfortunate then.

7

cygb:
Thanks for the input guys. It’s rather unfortunate then.

Maybe not, it all depends on what your level of experience and commitment are. You wanted ...

[Battery + Joystick/Oracle controller] → [RJ45] -->[ Encoder/Radio Transmitter] —> wireless —> [Radio Receiver/Decoder/Local Controller + Battery] -->[RJ45] —> [PT Head]

{I amended your original diagram}

The above might be easy enough if “we” knew what signals went across what pins. For all I know most are power and ground with a pair for some RS-232 like communication (I doubt it though).

Since you have the item in question you could make a breakout box for the cable (it’s the one to/from the controller you want to mimic) and measure what’s on them, starting with a DMM to find power(s) and ground(s). An O-scope would be handy to find out what being passed for signals on the other pins. If it’s really Ethernet (I very much doubt it), it seems to me that a wireless router could be used at the pan/tilt rig end and the joystick+controller at the other end fed into a PC to communicate to that router. You wouldn’t even have to do much in the way of your own PCBs and circuitry, just make cables and a BOB for each end.

If it’s some other link (much much more likely) … well that’s still do-able if you can “sniff” the lines to ferret out the data. That may take some equipment (O-scope) and time. My guess is that some servo type signals are sent from the controller to the “motors” (more likely continuous rotation servos). What you want to do is not that much different in concept than what’s done with RC planes.

Or it may be that the controller does nothing more than switch power to the motors on and off (doubt it but …). A DMM might be all you need for TE. Replicating the timing and sequence of the on&off with a local (dumb) controller and connecting that wirelessly to the output of your joystick+smart controller plus a transmitter need not be difficult.

If there’s feedback from the motors to the joystick+controller then it’s more difficult (timing lag could be an issue).

It’s really all a question of how comfortable you are trying to suss the wiring and signals out.