How can I trigger an action on one Android device with another Android device?

I recently got a new device and my old device will now be used as a music player with my bluetooth speaker. However, I wanna save battery by not having the old device's bluetooth on the whole time. What's the best way I can trigger an action to turn off bluetooth in my old device using my new device (ie. as I'm heading out)? I'm guessing there's a way to use Tasker to detect my new phone's location and then toggle bluetooth on the old device accordingly but is there another way that would be less resource intensive? I'm thinking maybe NFC? Like as I walk out of my room I tap my new device to my old device and it turns off the bluetooth and when I get back home the same action reactivates the bluetooth. Thanks