cable tv addressable box

[tishri]

hey guys,,
i need your advice how could i possibly make an addressable box using pic..
its expected number of devices is 100thousand

my first plan is to transmit rf signal
like:
transmit ----> 1 ON
100000 ON
999 OFF

those devices that recives that code will be turned off or on based on the command sent.

just give me idea if its possible using pic.. and how could i merge the signal from PIC to cable tv signal .. thanks

[sayzer]

Hi, Gimo

That's not sample you request, but a complete application ...

How much do you offer ???

Alain

http://www.picbasic.co.uk/forum/showthread.php?p=44062#post44062



As Alain asked in another post, let me ask the same question here.

How much do you offer?


-------------------

[tishri]

im just asking if this can be done using PIC... im not asking how to do it. im not also asking the schematics diagram or the source code .. :)

really, i just want to know if this is possible using Programmable IC's .. im just wondering.. if this is possible then maybe we could talk about the price. :(

[tishri]

i never thought that this forum is always talking about money... i wouldn't ask this question if i'm a pro. most of the questions raised here are school projects. so why talk so much about money.. pro's don't go to forums like this. :)

You know what guys im also a member of sql team forum and some visual basic forums. there we dont ask for money.. we help each other....

[sayzer]

Sure it is possible.

For example:

Assuming you have a very clear RF channel.
Say you have 100 units. Make them slave.
These slave units (devices) will be on listening mode on the channel.

Each unit will have a PIC , say 16F628A. Each PIC will have an ID number. Say ID = 1 to 100.
You will also have a master PIC and your master PIC will be the controller and sending the signal to the RF channel with two bytes.

First byte is the ID number.
Second byte is the mode ; either ON mode or OFF mode. Say Mode = 1 is ON, and Mode = 0 is the OFF mode.

When your controller sends the signal as
[ID,Mode]
then all of your PICs will check if the ID is their assigned ID.
When one of the slave PICs matches the ID then this slave PIC will take a look at the MODE.

IF the Mode is 1 then PIC will turn ON something.
IF the Mode is 0 then PIC will turn OFF something.


Is it clear enough so far?
All is free.

[tishri]

yes, its very clear, thanks
i just don't get the idea why you guys keep on asking for money..

well..,, i've got few more question ..

how about the possibility of combining it with video, audio, and signal that controls the turning off and on of the devices. Is this possible? does this affects the video or audio signal? and one more thing.. For you, how hard is it to build a project like this? [very easy,easy, hard, very hard]

thanks again .. hope its free coz this are just questions not complete applications..!!!

[ronsimpson]

There are pros on this forum. Many pros that give away what they get paid for at work. No pros few answers.

Why do some think the world is free. “make me some code” “can you make that for me” “I can’t put $30 into that”

[sougata]

Hi,

It has been a long time logging into this forum but couldn't resist myself to answer this thread. First about the $$money$$ part.

People in this forum do actually help each other out and the n number of posts prove that. This is the most popular and helpful place on the www as far as PBP is concerned.Pros and gurus here do help for free which have cost them n number of hours learning and working out.So my earnest request is that please try to avoid

i just don't get the idea why you guys keep on asking for money..
What sayzer meant was perhaps that it would be better to help somebody on a actual project that enriches this forum. Rather than the forum being treated as a answer machine. It feels good when you are part of somebody's hardwork but equally depressing when you find that only you were serious the other member was not. And sayzer was kidding....perhaps. Look into the posts of sayzer and you will find the answers about his contribution. I myself have been helped greatly by this forum. All for free...! Without the active guys on this forum I might have not acomplished success in many of my projects. Okay enough blah.. blah... now the technical stuff.

For an addressable system to work successfully you need to ensure that the signalling from your cable tv head-end does reach the last distribution amplifier. If you try to use the unused RF bandwidth you would end up modulating/demodulating your signals in the RF region and probably the cost factor would not be justified. So my recommendations are use the power line (mostly low voltage ac in the range of 40 to 80 volts) as your carrier and transmit your signals over it. (Sniff X10 on the net. PBP supports it) This would reduce the cost implementation of the signal mod/demod. Now if you could read the signal in your tiny little boxes to individual subscriber then you can take actions like block/unblock. RF relays are costly PIN diodes are not. To keep the scheme simple broadcast a packet from your headend that contains the inividual block/unblock commands. To make it even more reliable use a return to zero scheme that supports clock recovery at the PIC end. 5 consecutive block commands for example initiates a blocks and the same goes true for the unblock. This would ensure that erroneous decoding does not block customers who should not be.

Whew! That was pretty long. I hope the information is useful

[Archangel]

Sayzer taught me how to set up and implement timers . . . Free, and then opportunity came along and I taught someone else what Sayzer taught me, So on their, and my behalf, Thank You Sayzer !

[Normnet]

and how could i merge the signal from PIC to cable TV signal


A coax relay.
Expensive though, about $100 each.

Could anyone enlighten on the use of a DiSEqC switch for analog or digital TV coax switching?

"Ricks Satellite" (http://www.gofastmotorsports.com/rickssatellite2and4wayDiSEqCswitches.htm)

Norm

[Normnet]

What are the components of a DiSEqC switch?

Norm

[BigWumpus]

A coax relay.

No,
a coax relais may switch between to cables, he needs a modulator to put his information on the cable.

[nomad]

this is just about exactly the way cable companies did it with their old analog boxes. they had a digital control signal between channels that addressed a box and told it what channels to descramble. a friend of mine *cough* used to have a test box that blocked the control frequency [this case was 107mhz i think, selectable via dip switches for that box brand or cable carrier] and sent its own signal to the box. it would go through each address and activate all channels. eventually it would get to the address of the box connected, sometimes it took a few minutes. if i remember correctly it was a pic sending the codes.

[sayzer]

Sayzer taught me how to set up and implement timers . . . Free, and then opportunity came along and I taught someone else what Sayzer taught me, So on their, and my behalf, Thank You Sayzer !

Words are not enough to express what I feel now.

Keep sharing the knowledge we have.

Thanks very much Joe.

[tishri]

currently guys, here in the Philippines, most of the cable company uses analog signals.. is there a best way to use this technology(analog) from unauthorized use.

I am thinking of addressable taps or addressable box. hahahah

thanks a lot for sharing.. im still gathering information so I can have the idea where to start.