DIY USB customisable LED cluster with files

A project that uses a small PCB and optional 3D printed case (not needed) to create a very simple spray of up to 20 LEDs that are powered from any USB power supply capable of at least 300mA.  The LEDs can be fixed colour, colour changing, flickering, flashing, clear or diffused.  Basically any standard LED.

If the two pin sockets are used, the LEDs can be changed as desired.  The open circuit voltage is low, so putting an LED in the wrong way round will not damage it.

The end result is a very low power (just over 1W) spray of decorative points of light than can be left on continuously, as the running costs are virtually nothing.

If desired, the resistor values can be increased to reduce power further for battery powered decorations.