Smart button

 Yes. To dim and brighten your lights using the smart button, press and hold the button. The lights will first dim, then brighten. You can customize this action (long-press) in the Philips Hue app. The smart button is not designed to dim and brighten by turning the button on the wall plate. Though it may look like one, the smart button is not a rotary dimmer switch.

If your smart button came with a Philips Hue starter kit, set up your lights and Bridge before the smart button.

When you're ready to set it up, you can add it in the Philips Hue app: 

1. Press and hold the smart button for three seconds to activate the device. 
2. In the app, go to the Settings tab. 
3. Tap Accessories. 
4. Tap the blue + icon on the right top of the screen.
5. Tap Smart button and follow the on-screen instructions. 

Turn the button over and find the gray mark that indicates where you can open the battery compartment. Use a small, flat screwdriver to lift the back cover. Remove the old battery and replace it with another CR2032 (button cell) battery.  

The smart button uses a CR2032 (button cell) battery.