Background

We wanted to look at controling our Zoom Room TVs, Samsung commercial displays, using the Zoom Rooms “Native Room Controls” method, since Zoom says that the older HDMI CEC method for turning on and off the display is no longer supported.

The original Zoom “Device Operation Time” feature mostly worked for us1 on our simple Zoom Rooms, but the new Room Controls features would allow us to do more interesting things with other components down the line.

Our approach

Please see our gist for a configuration sample JSON that works with our Samsung QM-H series displays, using Samsung’s MDC service.

  • The excellent Samsung-MDC project helped us in all phases, from initial understanding of the MDC service’s capabilities, testing, and then later on configuration details in the Room Controls JSON. Comparing the samsung-mdc verbose output and source code for individual commands with Wireshark captures allowed us to see that we weren’t properly escaping our hex codes. This is an excellent tool that we will use for additional non-Zoom display control going forward.

  • Just Add Power’s comprehensive Samsung RS232 support pages for RS232C and Ex-Link formats confirmed we were on the right track and will be most helpful if we ever need to manipulate other Samsungs via Ex-Link.

  • Control Concepts has a Room Controls profile maker and an excellent guide that helped us understand how to format our command output as hex (though it appears you need to escape it with another \ when pasting it into the Zoom Room’s settings), and how to chain commands with parameters with the % symbol.

Footnotes

  1. I suspect HDMI CEC would have worked fully for us if we had read and followed the Duke DDMC’s fantastic guide when we got started, instead of finding it after the fact. ↩