I've got a new Samsung LCD TV here, and it has a serial-port on the back that can be used to control some functions.

The port is labeled "service only" or some such drivel, previously known as the "ex link" port. It consists of a 1/8" stereo mini-plug jack.

Here (attached) is a small C-program that I wrote, for sending commands to it over a USB serial adapter (hardcoded pathname for now). Wiring info is included at the top.

Now.. the TV has "120Hz" refresh, and a few heavily buried menu items for controlling the frame interpolation functionality. What I want, is a way to easily enable/disable that functionality, without having to navigate so bloody deeply through the menu system each time.

Thus far, I've figured out mappings between menu items and serial commands for most stuff. But not for the 120Hz controls..

Anyone else here got a 120Hz Samsung and want to play along?

How did you go about figuring this stuff out? I've got a Samsung TV (not 120Hz), and it's also got a "service port", although it looks like a standard 9-pin socket.

I found a fair bit from googling about, including an outdated mostly-correct 2008 command listing from Samsung themselves. Their site also has a newer 2009-2010 command spreadsheet, but it is totally inaccurate for the 2010 set I have here.

The DB-9 on your set may have the same kind of interface, and some older sets even had info in the user-manual for this stuff (no more, though).

Along the same lines.. if I power the set off, and then enter this sequence on the remote control, it gets me into "service mode": MUTE 1 8 2 POWER
Other samsungs had a difference sequence there.

Once in the Service menus, the UART can be changed into "debug" mode (as opposed to "uart" mode), whereby it becomes the Linux boot console for the TV (115200bps). My set appears to not accept input from the port, only using it for output. For earlier years, it was possible to login and gain control of the internal ARM system this way.

Cheers

The samygo project has lots of cool info for sets from the 2006-2009 era. No good for my 2010 set, though.

Here is the Samsung link for the 2008 RS232 Codes.

EDIT: Say.. I wonder if the DNIe function is the magic "on/off" thing I'm looking for? From googling, it does appear to be related.. gotta play with that now, I suppose.

Interesting.... I have two Sharp Aquos LCD TV's at work, and the serial protocol is listed in the end user instructions!

Hey Mark, let us know if you brick your TV. Just be careful not to issue any commands you may not be able to revert from. That goes for using remote-based service modes or cable link.

Have you searched remotecentral.com for any info/links?

It's all pretty safe, I think. Especially while still within the 30-day return policy.

The interface seems to only allow commands that could otherwise be issued more cumbersomely using the remote control. So there's not likely to be anything that could brick it there, at least not on the "uart" setting.

I have accidentally issued the "reset everything" command a few times now.. Bloody nuisance that, but at least I've also now got a script to restore most of the settings afterwards.

Still hunting for the codes to manage the 120Hz settings, though.

A useful pair of codes are the "power on" and "power off" commands, which my MythTV box is now happy to issue on our behalf. If we could also find the 120Hz ones, then the TV remote control will become completely unnecessary, and could be removed from the coffee table.

I've put the RS232 explorations on hold temporarily, and now moved on to DLNA functionality.

MythTV, to my surprise, has a built-in uPNP media server, which the new Samsung TV finds on the home LAN (ethernet). Cool.

Except when using the TV to play video files directly (over DLNA from MythTV), the FF/REW buttons on the TV remote don't work. Not Available says the TV when they're pressed.

Apparently lots of other people have noticed and complained to Samsung about the same issue. Some people even claim to have gotten them working with older TVs (2008=2009) by patching and reconfiguring various uPNP server software packages, but reports are rather spotty about that.

Bit of a shame, because when the TV reads/plays the media directly, the results are better than from MythTV + NVidia VDPAU. So for now, if I want FF/REW to work, I have to copy the files to a USB drive, and then let the TV read/play from the USB drive. No problem using FF/REW that way. Odd.

Some of the SamyGo project folks even take this a step further, hacking the TV firmware to mount the server's media via NFS or Samba, over top of the usual USB-stick mount point within the TV. So the TV then thinks it is playing from a USB stick, and enables FF/REW. Cute.

But it only works on the 2008-2009 sets, not on my 2010 set with its crypto-signed firmware.

Mmmmm.

Note to self... Self, doing a good job by avoiding Samsung products.

Because all the other brands do this flawlessly right? I think Mark's actually pretty lucky to have it working as much as he has.

In UPnP-land, and especially in DLNA-land, FF/REW needs specific support on both client and server. (The client issues HTTP content-range requests with timecode ranges, not byte ranges.) A priori, it's just as likely that your server has missing support as that your client has. (Especially given the comment about other folks getting it working against better servers.)

Peter

Mmmm.. thus far, none of the server software I've tried/hacked has provided FF/REW.
But now I've stumbled across a strong recommendation for Serviio.

Not open-source, but close enough. I'll give it a try here this morning.

I guess you missed the other messages where I've commented on Samsung (not TV specific)... On top of that, I've seen enough Samsung TVs in person, plus had enough automation-related run-ins to know that Samsung likes to change everything up from model to model and doesn't really care too much about discrete codes. They're not one of my favorite companies.

Mark, you may end up having to do a macro to get the 120Hz controls working remotely.

No joy there, either. Thus far, nothing has done it any better than MythTV's built-in server, so I'm sticking with that.

I haven't actually see anyone post that FF/REW works for them on a "C" series ("C" == 2010) Samsung TV, with _any_ server. So perhaps Samsung have simply not enabled FF/REW for DLNA access.

Weird though, because the uPNP browsers I've tried out show that the TV does report some kind of FF/REW support.

Cheers

So noted.

Holy shit, has it really been 5 years?