How can contact closure from NVR change input on TV?

[Greg Castiglione]

The video output from my 16 channel LOREX NVR outputs a 4k HDMI signal that I feed into a 1 in 2 out 4K splitter. One output out of the splitter feeds a dedicated 50" monitor in my main living room. This 50" TV constantly is used 100% off to view the output of the NVR. The other HDMI 4K output out of the splitter goes into my main tv which is a 75" . However it goes into HDMI#2 INPUT of my main tv. 99% of the time my main tv is using HDMI#1.

Now I want to use a dedicated contact closure output from the NVR to change the big tv's HDMI input from HDMI1 to HDMI2 whenever the NVR outputs a contact closure. Any ideas on how I can impliment??

When a specific camera sees motion, it triggers the contact closure from NO to NC for a programmed amount of time. Just perfect!! I have a 75" SONY. I need to have the Sony change its HDMI input using contact closure. Ideas? ?? -Greg-

 

[TonyR]

Perhaps a 2-port HDMI switch (2-in, 1-out).

Leave the TV on HDMI1, connect this switch's output to it, switch what goes into it, either the default input (satellite, cable, etc.) or the NVR.
It's only 2 ports so consecutive button presses toggle between input 1 and input 2. You'd have to hack the pushbutton with either an external relay (NVR alarm output?) or like amazon reviewer "J.D." did with a NPN transistor to enable a Raspberry Pi to perform the button press. The device is only $7 so no big deal if your hack goes haywire (see below):