RS485 over wireless (cctv ptz controller without wires)

i know there are a few radio hams on here, and other knowledgeable people when it comes to electronics and the like,

i've got a cctv system in my aviary, the dvr is located about 30 feet from the house, video is sent to the bedroom and living room tv via a length of RG6,

basically i want to use a PTZ controller in either location (bedroom or living room) without having to faff about with wires,

standard way is to run some twisted pair wire from the back of the ptz controller to the cams, but i cant do that really as i want to be able to move the ptz controller about with ease, and not faff about changing wires over, fitting and removing terminating resistors and all that.

So i want to send the ptz control signals wirelessly, the ptz signals are sent using RS485, at 9600 baud,

ideally i'd like to be able to buy a couple of small radio modules, connect the data out from the ptz controller to the data in pins on one module, apply power, and at the other end, data out to the data in on the cameras and power, and have it work... with a little setting up i guess to set the baud rate etc.

searching the net i can find lots of hits for radio telemetry solutions, but they are the 5 grand systems used on those wireless cctv cameras put up outside trouble makers homes by the council, and send the video back as well as relaying the ptz signal and work over many kilometers, or possibly modules that might work, but from china with limited documentation on them,

i need basic ptz signals sent one way over about 50 feet max, and as cheap as possible, and if possible using modules bought in the uk,

the ptz controller runs on 12 volts, and i will put in batteries to get that voltage, i imagine a radio modem type thing will want 5 volts, so no probs putting in a regulator for that,

Any help gratefully appreciated.

Reply to
Gazz
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RS (and therefore others) have RF data modules, you'd have to convert from RS485 to CMOS/TTL signals though and that's a design job.

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than sending RS485 over RF, would it be possible to put the PTZ controller near the camera, and use radio control switches to mimic pressing the PTZ controller buttons. That way you only need to carry switch impulses over RF rather than data. Remote control sockets in a pack of 1 controller and 3 sockets are quite cheap.

Owain

Reply to
Owain

the ptz controller has quite a few buttons to press, but more impotriantly it has an analog joystick, which varies the pan and tilt speed depending on how far you shove it in the direction you want,

i do have an infra red ptz controller and the dvr has ptz controll built in, and using a couple of those remote extenders i can use the infrared remotes, but it's the variable speed and multi direction of the joystick i want the most,

not to mention, the dvr's built in ptz controll is very clunky... despite having arrow keys on the remote, you cant use them to direct the camera... instead you use them to select the arrow on screen, then press the centre button to move the cam in that position, to zoom in, it's down arrow 4 times, then accross, then enter button and so on, bloody annoying and i havent even mentioned the ptz overlay on the screen that covers the right hand third of the picture,

The ptz remote unit is a little better, the arrow keys move the cam, and it has dedicated keys for zoom, iris and focus controls and presets etc, but again, it's the lack of the analog joystick i miss, can't even move the cam diagonaly using the infrared remote ptz unit,

i am wondering about using rs485 to rs232 converters, as there seem to be plenty of rs232 radio links, but it just adds to the complexity and things to go wrong,

Reply to
Gazz

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course its in china, and i cant seem to see any data sheet links on the sellers page, a few things bothering me tho, says 1 mile range... way too much for me, and hence will waste battery power, but then it says 300m distance, and mentions signal levels, and only lists rs232 : 4.5 - 5.5v, i read somewhere rs485 is 1.5v to around 5v,

Wonder if it'd work for what i want tho... would really have liked a bit cheaper, but i guess it's the rs485 bit, rs232 radio links being much more prevelent and thus cheaper.

Reply to
Gazz

I was under the impression the RS485 was simply an EIA standard for a differential drive bus - so I would not be surprised if in these situations that require relatively low speed serial data connections, the actual comms circuitry is basically a conventional serial data link like that used with RS232. Any chance of popping the lid of something and playing hunt the UART?

Reply to
John Rumm

It is. Nothing to do with data formats. It's basically RS 422 with bidirectional drivers so you can do half-duplex on the same wires. That's a higher layer and does require some protoicol to be implemented.

RS485 transceivers are dirt cheap.

MBQ

Reply to
Man at B&Q

Man at B&Q" wrote

please point me to a site where i can buy a couple then please, as i'm getting lost with all the tat from china out there that may or may not do the job.

unfortunately, i know just enough about electronics to get me into trouble, and all these data protocols and stuff is pretty confusing,

i'd love to find a plug and play option, or something that needs only a little tinkering to get working, dont want to end up with yet another box of bits and pieces that almost worked but didnt hidden at the back of the shed.

Reply to
Gazz

Search eBay for RS232 bluetooth?

e.g

Arduino Serial Bluetooth RF Transceiver Module RS232 SL

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"Coupled Mode" halfway down the page, or ye can talk via Bluetooth connected to a PC.

It's China, cheap but slow boat....

Or a UK based company

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No experience on using any of the above...)

Reply to
Adrian C

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