Lutron switch - turn off lights when nobody is in the room?

Question

I have a room where the lights are controlled by a Lutron Caseta switch connected to a Lutron SmartBridge and Amazon Alexa. UPDATE: I don't require the use of Alexa in the solution, I'm just saying I have it, in case it helps.

What is the simplest way (with the least amount of additional hardware) to automatically turn off the lights when the room is vacant?

Additional info

• The room is relatively small (typical kid's bedroom in a U.S. home).
• The switch's line-of-sight to the room is obstructed, so a traditional motion-sensor switch is not an option. The motion sensor has to be placed on a different wall from where the switch is located.

Some quick research on the Internet indicates Lutron motion sensors don't work with Lutron Caseta or SmartBridge and the most popular way to implement this requirement is with a Samsung SmartThings hub and Samsung motion sensor, using a cloud-to-cloud connection from SmartThings to the Lutron SmartBridge. Is there a simpler solution?

Answer 1

I finally implemented this using the Samsung SmartThings hub and Samsung motion sensor, using a cloud-to-cloud connection from SmartThings to the Lutron SmartBridge. Did not find a simpler solution.

Answer 2

Grid Eye sensor can sense the human presence in the room, you can interface that sensor to any cheap microcontroller and control the light through relay.

For reference, you can explore Panasonic Grid-EYE® 8x8 (64) pixel infrared array sensor.