Converting a security camera to be wireless

[c3ns0r3d]

Hi everyone,

I'm new here and to electronics in general, although I understand most of the core concepts.
As an intro project, I've decided to attempt to mod an old security camera to send signals wirelessly instead of through the 10m cable provided. I have had a look at the internals, and it outputs a video and audio signal to a 4-wire DSL-looking cable. The power also comes through this cable. This currently connects to a scart adapter. What I would like to do is to have these signals be sent to a receiver which can plug into USB, the software to receive these signals isn't really of concern as of now, so any clues on how to go about this or what to look into would be much appreciated. I have thought about using a project board to send it over IP, but that would be less secure, and would limit the areas in which I could use it.

I would also like to understand the circuit, as I feel this would help with both my knowledge in general and understanding why whatever will work for this project works.

Thanks in advance,
c3ns0r3d

 

[(*steve*)]

Sounds like a pretty advanced project. The interface boards I've seen in network video cameras are way more complex than the camera boards.

 

[c3ns0r3d]

I don't mind complicated really, I find it's often the best way to learn things. In my head right now there are main challenges:
- Building the transmitter, I suppose bluetooth might work? My teacher also told me to look at xb radio
- Building the reciever
- Adding in a power supply
- Finding what signal is being outputted and converting it to digital

Please correct me though, I'm here to learn.

 

[BobK]

I don't mind complicated really, I find it's often the best way to learn things. In my head right now there are main challenges:
- Building the transmitter, I suppose bluetooth might work? My teacher also told me to look at xb radio
- Building the reciever
- Adding in a power supply
- Finding what signal is being outputted and converting it to digital

Please correct me though, I'm here to learn.

Are you willing to spend about a year on this? That is what I expect it would take if you are a good learner.

Bob

 

[c3ns0r3d]

Very willing, I have a lot of free time generally

 

[CocaCola]

From what appears to be 'toasting' on the J1 take off I believe a good place to start would be getting a lot of soldering under your belt... Then enroll in a few electronics classes and learn embedded micros...

Or you could spend everyday Googling and learning yourself... If you can't find a protocol/datasheet for that camera you will need to figure out the protocol on your own, lots of trial and error work...

 

[(*steve*)]

I would start by trying to to an a-d on the signal coming from the sensor. Then capture and buffer that. Then send out a frame via bluetooth. rinse and repeat.

 

[c3ns0r3d]

Is it possible to tell which wires do what in J1? I've been assuming that the one in hole 2 (taking it from the left on the side with the sensor) was the power and the other three were the video and audio in some combination.

For the conversion/capture, would a set-up like this work?

 

[(*steve*)]

You will need to find the specs on the board. It seems to have a part number on it, have you googled for it?

 

[c3ns0r3d]

I have googled both CT100B(/w) and Protronic 0L2, neither of which came up with anything useful. If I were to compare the rating with the voltage measured during operation on the different junctions, would that tell me at least the power cable?

 

[donkey]

ok how easy or complicated do you want this to be?
I just spent $20 and converted some old cameras to wireless (semi wireless, need power still)
depending on the plug you have I might have a quick solution for you
sound might be different though

 

[c3ns0r3d]

I don't want it to be so easy that I don't learn anything, and I don't really want it to be impossibly hard, but I am still at that stage where most anything will teach me something or other.
I've just checked the external plug setup, and essentially, the cable goes into an adapter which sends the audio L and R and a composite video wire to a scart cable and a copper cable to a plug which outputs 9V 100mA DC.
The sound's not really a problem for me, it's kinda non-essential.

 

[donkey]

ok the easiest way I got for you is buy a wireless reversing camera kit like
http://www.ebay.com.au/itm/121020716825?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
thats a bnc connector so some modifications will be needed
its doable to network it, but that is going to take a while, the module I linked you too needs a reciever which is easy to get.ooking it up to a network from there should be no problem

 

[CDRIVE]

Your cam appears to be using a 4 conductor UTP where two conductors carry the video while the other two supply power. So a bigger question would be .. how are you going power it?

Chris

 

[c3ns0r3d]

Thanks donkey, I've found the equivalent on the UK site, it says 2.4GHz, so is it broadcasting bluetooth? I think it's around that frequency for it.

From what I've seen inside the SCART connector, three of the cables get sent into it from the adapter, and only one gets piped through to the power. The plug has an output of 9V, so I thought I might use a Lithium PP3, although I'm not sure on the suitability of long term installation with that. According to the plug, it has a drain of 100mA and the capacity of the lithium batteries are around 1200mAh, so would that be around 12 hours?

 

[davenn]

it wont be bluetooth unless it specifically states that...
do you see a BT symbol ?

normally cameras on 2.4GHz are just using that freq to transmit composite video
to a receiver

Dave

 

[donkey]

hey as dave said its not likely bluetooth. I work around these setups and you need a specific reciever for it.
for direct tv or tv card in a computer use
http://www.ebay.com.au/itm/121020717496?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

for USB on a computer
http://www.ebay.com.au/itm/270992236139?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I am not recommending these items just showing what is available. A general rule of thumb is the "4CH" or 4 channel which means it is neither bluetooth nor ip but uses a straight rf to send the video. the four channels are usually pretty close to
CH1 = 2,414MHz; CH2 = 2,432MHz; CH3 = 2,450MHz; CH4 = 2,468MHz
so check the transmitter and reciever match up.
the big issue is what will interfere with it. 2.4ghz is so widely used that in your house your cordless phone, wifi, and other items may all be on that frequency which could be a direct interference making the range of the item alot shorter.

to get this to work on a network I can think of a few ways but most of my ideas revolve around a spare computer. andmost of these need programming knowledge as the camera will nedd a driver made or a tv card with av (you can find usb versions for next to nothing)

anyway to get the camera working I recommend you jumping online finding a cheap in car monitor... even 2.5inch will show you if your camera is working and they go for around $20 au so its cheap enough that you won't feel bad if you hack it a little

 

[c3ns0r3d]

I'd probably go the USB option, my ideal set-up was to have it broadcast to the computer directly.

Wherever I would use it, I think the biggest threat would be from a wi-fi network (there are two different ones I can think of, one being run from a single router, the other from a fairly large network of around 400 users). What do you think the max range would be, or would that be a bit impossible to predict?

I also thought of making a small relay, just a reciever into another transmitter, would that be feasible?

I probably wouldn't need to network it, as I would be the only one accessing it, although programming isn't really an issue, I came into electronics from there.

 

[donkey]

range is totally uncalculatable (its a word i tells ya)
the peak efficency is 100metres, this goes down with several factors, first being obstacles, is there anything in its way? that has to be calculated with density etc etc etc etc. to much there
then there is competing frequencies, what else is on the same bandwidth? at how many watts is it being broadcast? how "heavy" is the traffic?
and last but not leastis power to the unit.is it stable? are you providng enough current andvolts to get this working right?

the EASIEST way to calculatedistance is to hook it up and go for a walk to see how far it reaches.
as for your relay it too is possible just make sure the connectors are the same AND the frequencies are DIFFERENT. ifyou hook up a reciever to a transmitteron the same frequency it will just cause interference rather than extending the range, the ideal wayto do this is buy a 4 channel version use channel 1 on the camera and first reciever and channel 2 on the transmitter and 2nd reciever.