I run a Hifi streamer (well two of them, in fact) using an older Raspberry Pi 3+ and a DAC HAT. Brilliant HiFi sound and works really well with local music, music from my NAS, Spotify, Tidal, Qobuz etc. If anyone wants to explore this take a look at MoodeAudio, Volumio, or PiCorePlayer. Also, search on Youtube for Darko and Raspberry Pi - he has some very good overview videos and is a rare serious Hifi buff who can explain things clearly to us lesser mortals. What's all this got to do with Neo Trinkey? Well, the DIY streamer may well have Hifi audio to rival £500 or more, higher-end Hifi units but it lacks a display. More precisely it lacks any indicator to show what sample rate and bit depth the current track is playing at. Not necessary info, but it is nice to know if you are listening to CD quality 44.1/16 bit audio or whether it is hi-res 96/24 or even very hi-res 192/24. Problem is the DAC HATs cover the GPIO pins and so a GPIO display isn't easy without some work. Enter the Neo Trinkey - a USB RGB light. I wrote a fairly simple piece of Python code that every 3 seconds checks whether music is playing and if so sends the sample rate/bit depth to the Neo Trinkey. This then changes colour depending on the sample-rate - yellow for CD 44.1kHz, magenta for 96kHz and cyan for 128kHz (and different shades for the in-between rates like SACD's 88.2kHz). But the Neo Trinkey has 4 LEDs, so 3 are used for sample-rate and the other is R, G, or B depending on the bit depth of the audio stream (16, 24, or 32) The Trinkey has touchpads - perfect to set up as a brightness control so the indicator can be turned right down (or even off) if the mood dictates. A great product for a project like this - simple to code using the Arduino IDE. Setup was easy and the Adafruit help pages, examples and libraries make it very easy to hack the basic sample code to provide a very useful little USB indicator light. Now trying to think of other projects to use some more of these for - at that price it would be rude not to! Pictures below illustrate a normal 44.1kHz/16bit CD track and a really high-end 192kHz/24 bit track - I wish my ears could really tell the difference :-)