Change the TV channel over IP

tv-channel-change-over-ip

[Mustafa Dur] wrote in to tell us about his hack to control the television with a smartphone. Now the one-IR-remote-to-rule-them hacks have been gaining popularity lately so we assumed that’s how he was doing it. We were wrong. He’s using his satellite receiver to provide the Internet connection. It pushes commands to his LG 47LH50 TV which has an RS-232 port.

The image above is the back of another LG television (it came from a forum post about controlling the TV with a PC). [Mustafa] is using a Dreambox DM800 satellite receiver which also has a serial port an he can telnet into it. He searched around the Internet and discovered that it should be possible to connect the two using a null modem cable. His initial tests resulted in no response, but a tweak to the com port settings of the box got his first command to shut off the television. After a bit of tweaking he was able to lock in reliable communications which he made persistent by writing his own startup script. From there he got to work on a Python script which works as the backend for a web-based control interface.

If you want to find out what else you can do with this type of serial connection read about this hack which used a script to try every possible command combination.

11 thoughts on “Change the TV channel over IP

  1. I did something very similar to this with my home theater setup, where I connected the RS-232 port on my tv to my HTPC. That way, I can control all of the telivision’s functions through XMBC.

    1. That’s what I was wondering. In the past I looked it up with the interest of developing a small dongle to plug in between an HDMI cable and one of the devices. the HDMI CEC specs were very easy to find and very detailed. Enough so that I still have the project on hold until I get a financial break to buy some hardware to test it with.

    2. Not all functions can be controlled over CEC but the most functions can be controlled over RS232. It’s my experience with my LG TV.

    3. RS-232 control allows for very simple control, even through bitbanging. In addition to that, only some TV manufacturers bother to implement CEC.

  2. Curious…. what is the connector style for the two ports labelled “AV-1″ and “AV-2″? I have never seen that type of connector. I notice it’s a PAL TV(the Antenna port)…. maybe it’s a European thing?

    1. I was. With a little hacking (access to service menu by using specific ir commands), you can use it to hook up an external hdd or a flash drive and play media (images/music/movies – even with subtitles) from it. It’s quite nice if you bought a TV that didn’t have these functions enabled by default (just like my 26LG3100). Search for “lg usb hack” or maybe even more precisely: “your_tv_model usb hack”. Please mind that (at least for me) getting into service menu requires using a remote with custom-rogrammable RC5 commands or a uC bit-banging a red led ;) You can find pieces of code for the uC on the net.

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