Phone apps can be frustrating, especially when relying on them to interface with other products — Chromecast audio, for example. Not only can it be difficult to reliably control outside audio players reliably, but you will also still need to locate your phone if you ever want to know what song is playing or quickly control the playback options. Particularly working from home, you may well want a more convenient way to have music in the background during the day. The latest series of projects from Glen Akins has been focused on solving that problem. First, moving the music-playing ecosystem to Linux and installing a wired Dante digital audio network, then building a scrolling LED display to always show what song is playing. Now, the system includes a Wi-Fi-connected Mopidy music server remote control.
The earlier projects in the series already have a lot going. Mopidy and Pianobar and used to play Spotify and Pandora in a Linux environment, and Audionate Dante input and output adaptors distribute the audio over Ethernet. The display that tells you what is currently playing at a glance is comprised of two LED display boards and a controller board, and a Particle Photon on the controller board connects wirelessly to two different WebSockets servers to retrieve the music data it is showing. The remote adds a touch more convenience to the setup.
The wireless controller board for the remote consists of a Particle Photon and six NKK UB2 series amber illuminated pushbuttons to skip or replay tracks, pause and play, mute, and control volume. Each pushbutton is connected to the Photon with a 1k ohm pull-up resistor. When not pressed, this keeps a logic of 1 on the input, and when pressed, the input pin is grounded and presents a logic 0. The LEDs on each button are powered from +5V through a 330-ohm current-limiting resistor and are connected to an NPN transistor switch. When the Photon output is 0, the transistor switch is off, and the LED is not illuminated. Simple solutions are the best.
The remote’s software runs on the Particle Photon and is built using the Particle online IDE. The environment supports over-the-air updating, allowing software updates without connecting the remote to a computer or taking it apart. All of the coding used for the controls is available on the blog, along with schematics for the board and design files for the casing. Completed, the remote makes the finishing touch to a more convenient household music system.