Transmit an RF signal over cable

[mag]

Hi all,

I have no programming or networking experience, however I am trying to solve a problem, which if feasible, I will have someone else work on. I need to locate a camera some distance away from its remote, which wont be amenable to wifi (tree cover, distance, obstructions).

Anyway, what I would like to know is; is there a way to receive a wifi (or bluetooth) signal from a camera remote (giving on/off/shutter functions etc), and convert that into a signal that can then be carried along a cable, and rebroadcast at the other end to be used by the device (eg camera). Note, it HAS to travel via cable; repeaters/boosters etc won't be able to be used.

Any help on this would be much appreciated.

Regards,

Marcus

[PiGraham]

Use Cat5 ethernet? Fibre optic?

How far away its the camera?
The cctv industry has been this sort of thing for years for video and control.

[mag]

Use Cat5 ethernet? Fibre optic?

How far away its the camera?
The cctv industry has been this sort of thing for years for video and control.

Using Cat 5 would be ideal. But how would I convert the RF signal from the remote, into a signal that can be transmitted along this cable, and then rebroadcast as an RF signal to actuate the camera? I realise there may not be an off the shelf solution, but do you think it can be done?

The camera is approximately 100 metres away, but will be down a cave, with trees, rocks and other obstructions blocking an RF signal. Repeaters/boosters etc wont be able to be used, and I cant hard wire the camera, the signal must be RF

Thanks

[PiGraham]

How about a Rasberry Pi at each end of a Cat5 cable?
One talks wireless to the cameras and the other talks to the remote.
Is the remote-camera connection WiFi, Bluetooth, Zigbee, 433MHz or some proprietary system?
If it's straight WiFi you may only need a bridge at each end of a cable. TP/Link do some nice small cheap modules that would do.

RF over Coax is possible, of course, but you have to sort out impedance matching / signal coupling and maybe line drivers.
You clould read up on transmission line theory. Impedance matching and VSWR and so on.
A reel of RG59 coax can be had for not much money.
I assume the remote and camera are not designed to attach to coax, either an external antenna or cable.
It seems unlikely that a presumed hand-held short range radio remote will be able to drive a signal down 100m coax and drive an antenna sufficiently to be received by the camera.

Perhaps you could put the remote near the camera and control it's button inputs with a networked Pi controlled over 100m Ethernet from another Pi or other networked device.

[keitho]

I use baluns from cpc.co.uk to transmit composite video from camcorders over 300 metres of cat5. - part no av 18767 There are also 2 audio channels which could be used for a modem link or voice.

[mag]

thanks for your reply PiGraham...

Is the remote-camera connection WiFi, Bluetooth, Zigbee, 433MHz or some proprietary system?
If it's straight WiFi you may only need a bridge at each end of a cable. TP/Link do some nice small cheap modules that would do.

I am trying to do this with a GoPro camera, which I believe uses 2.4 ghz, or a Contour, which uses Bluetooth.

I assume the remote and camera are not designed to attach to coax, either an external antenna or cable.

That is correct; no design for antennna connection

Perhaps you could put the remote near the camera and control it's button inputs with a networked Pi controlled over 100m Ethernet from another Pi or other networked device.

Do you mean mechanically activate the button, like with some servos?

Thinking outside the square on this one, is it possible for a Pi to "learn" whatever is encoded in that RF signal, so that a remote is not needed at all i.e the Pi will send all commands down the cable to be broadcast at the other end?

Thanks again

[PiGraham]

I use baluns from cpc.co.uk to transmit composite video from camcorders over 300 metres of cat5. - part no av 18767 There are also 2 audio channels which could be used for a modem link or voice.

Yes, that works well for video, but video is <5MHz, not 2.4GHz.

[PiGraham]

thanks for your reply PiGraham...

Is the remote-camera connection WiFi, Bluetooth, Zigbee, 433MHz or some proprietary system?
If it's straight WiFi you may only need a bridge at each end of a cable. TP/Link do some nice small cheap modules that would do.

I am trying to do this with a GoPro camera, which I believe uses 2.4 ghz, or a Contour, which uses Bluetooth.

I assume the remote and camera are not designed to attach to coax, either an external antenna or cable.

That is correct; no design for antennna connection

Perhaps you could put the remote near the camera and control it's button inputs with a networked Pi controlled over 100m Ethernet from another Pi or other networked device.

Do you mean mechanically activate the button, like with some servos?

I was thinking of opening up the remote (get a spare one) and wiring GPIO into the switch circuits. It is possibly the easiest option for someone with no programming experience since there are ready to go solutions for remote control of GPIO over networks. You should be able to "push the buttons" via a web page viewed on your smartphone.

Phone ---[WiFi]--- WiFi bridge ---[200m Ethernet]---- RasPi ---[gpio]--- GoPro remote ---[WiFi]--- GoPro

The WiFi bridge could be something like a TP-Link TL-WR702N

However, I see the GoPro remotes are not Pi-cheap.

Thinking outside the square on this one, is it possible for a Pi to "learn" whatever is encoded in that RF signal, so that a remote is not needed at all i.e the Pi will send all commands down the cable to be broadcast at the other end?

Thanks again

That may well be possible. Fist page on Google got me here, which may tell you something. There are ways to "sniff" WiFi communications and if you know the network SSID and password to connect, and the control protocol to communicate, you should be able to get a Pi to pretend to be GoPro remote. If you search you may find that someone has worked this out.

[Mortimer]

The GoPro Remote is a Wifi device, so I would be surprised if it isn't possible to replicate the signals from a computer.

Wireshark the wifi network traffic between the remote and the GoPro, and reverse engineer the command sequences?