This is my first post-retirement hobby project: a remote controlled speaker selector switch box. I have small speakers in various rooms of the house, with all wires coming down to the stereo amplifier in the living room. Previously, I had a manual switch box that required one to actually flip physical switches. Now the same can be done from anywhere in the house, from any device that has a browser, such as a smartphone or tablet.
The box also has manual pushbuttons on the front and LEDs to indicate which speakers are on.
Yes, you can buy these things but this was a fun project and a great learning experience.
Internally, the unit uses an ESP8266 WiFi module as the brains. It scans the buttons and controls the relays and LEDs, and implements a simple HTTP server. The project uses Arduino libraries ported to the 8266.
The enclosure was handcrafted from sandlblasted aluminum (thanks Grant!) and solid oiled walnut.