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lg oled rs232

Posted: Sun Sep 09, 2018 9:14 pm
by Nnuudd
has anyone had any experience of controlling lg with rs232. I have connected the 3.5 jack to a centro 8m and tried codes I found on the internet with no luck, plus connecting using Hercules to see if I get any feedback but getting nothing at all. wondering if the port has to be enabled in a service menu? ... 1388519161

Re: lg oled rs232

Posted: Wed Nov 07, 2018 6:42 am
by ask4mikie

I was wondering if you still needed help with rs-232 on your lg tv?

The first thing I can tell you is you must have the correct cable or rs-232 will never work. There are 2 types of cable, named "straight through" and "null modem."

Straight Through Cable Pinout

Tx 2_______________________2 Tx

Rx 3_______________________3 Rx

G 5_______________________5 Gnd

As you can see, in this cable pin 2 on one end connects "straight through" to pin 2 on the other end. Tx is Transmit, and Rx is Receive. In other uses of rs-232, some of the other pins are used, but in the AV world this simple setup with 3 wires is normal. I should also note that I am referring to the pins on a 9-pin rs-232 connector. The cable for the lg is a special case.

Null Modem Cable Pinout

Tx 2_______________________3 Rx

Rx 3_______________________2 Tx

Gnd 5_______________________5 Gnd

In the null modem cable, notice that the Tx and Rx Pins are cross-connected, that Tx on one end is connected to Rx on the other, and vice-versa.

You will also need to set the rs-232 parameters correctly for communications to occurr.

Let me know if you need more assistance, and also the model number of your lg tv.


Re: lg oled rs232

Posted: Fri Nov 09, 2018 7:53 am
by Nnuudd
Thanks mike

I did try both pin outs but didnt have any luck and i think the parameters were corect but as i struggled to find much information on it then it may not have been.

My tv is LG OLED65E6V
I will get it all out and give it another go
Thanks for your help!

Re: lg oled rs232

Posted: Tue Nov 20, 2018 12:55 am
by ask4mikie
Here are some more troubleshooting ideas:
  • You could use a multi-meter and ohm out (test for continuity) your cable. On the page you attached, there are 2 cable layouts. On the first one,PC pin 2 is connected to TV pin 2, and PC pin 3 is connected to TV pin 1. On the 2nd layout,PC pin 3 is connected to TV pin 2, and PC pin 2 is connected to TV pin 1. So there are 2 drawings, one is crossed, and one is uncrossed! Very helpful! Apparently this confuses even LG.
  • You might try a little gadget called a "null-modem adapter." This is a connector with wires 2 and 3 cross-connected. A null-modem connector changes a straight through cable to null-modem, and a null-modem cable to straight through (like a minus times a minus is a plus). Even if you are sure you have the correct wiring, a null-modem adapter may solve the problem. It has happened to me. They are pretty cheap on the web.
  • Please verify that your rs-232 parameters on your Centro 8m are correct. There is a web page on the Centro where you can set them. I found a document on the web, and according to it the correct parameters are baud rate = 9600, data bits = 8, parity = No, stop bits = 1. These particular settings are very common. Flow Control, RTS, and DTR should be UNCHECKED.
  • Often there is a setting or settings somewhere in tv menu to allow rs-232 control. Look for something like "External Control" or "Network Control". There may also be a setting to keep the rs-232 control port active when the tv is in standby. Without this set, you may not be able to turn the tv on.
  • You may want to download a program called Hercules, from the HW-Group. With it you can send rs-232 commands from your pc. This makes it easier to test commands and verify they are correct. You can also see the response from the tv. Once you see something back, even if it's garbage, you know you are getting close. Once you know the commands work, then you can work on getting Demopad to send them correctly. This breaks the problem up into smaller bites.
  • You may need to set the Set ID in the commands. The LG document I found can connect to 99 different tv's, 1 - 99. An ID of zero is received by all connected tv's.
  • Check the COM port setting in your Demopad project. Com port 1 is port 7501, com port 2 is 7502, com port 3 is 7503, com port 4 is 7504.
This is the document I found: ... 0Guide.pdf

Hoe something here helps you! Let me know how it goes!


Re: lg oled rs232

Posted: Tue Nov 27, 2018 8:23 pm
by asimp11
Sorry I did not see the post, have been too busy! I have done a lot of the LG business TVs using the same 3.5mm jack. From memory you have to enable shop mode which you access through a discreet sub menu using your remote. Can't remember it but you can google that, which is what I do. Also I think there might have been a pre code before each code or on/off code, not sure but I will ask my colleague then get back to you.