Introduction: MIDI 5V LED Strip Light Controller for the Spielatron or Other MIDI Synth

About: We are fascinated by and enjoy making STEAM projects.

This controller flashes tri-colour LED strip lights for 50mS per note.
Blue for G5 to D#6, red for E6 to B6 and green for C7 to G7. The controller is an ALSA MIDI device so MIDI software can output to the LEDs at the same time as a MIDI synth device like the Spielatron. The tri-colour 5V LED strips and Arduino Nano were purchased from Banggood.

Step 1: Have a Look at the Final Outcome

Here the controller is operating with the Spielatron. Both are registered as MIDI devices using ttymidi as per our Instructable on sending music to the Spielatron. Both the Spielatron and the MIDI lights are sent the same music track from LMMS.

Step 2: Making the Printed Circuit Board

We routed the PCB using the dxf file provided.

Step 3: Populate the PCB

Populate the PCB with three 10K resistors and three BD681 NPN Darlington transistors and single in-line header strips as per the schematic diagram provided.

Step 4: Mount the PCB Onto Plastic Stand-off Mount

Note that not all the pins of the Nano are used so it is not necessary to put header pins for the whole length, also there are some spare holes and pads that are for another project that use this same board as per the picture above.

Mount the PCB on the 3D printed plastic stand-off mount. The plastic mount is printed from the stl file provided.

Step 5: Terminate Leads on the 5V Tri-colour LED Strip

Terminate the leads on the 5V tri-colour LED strip noting the order of the pins being

5V +ve




Step 6: Connect LED Strip, Program the Nano and Add to Board

Connect the other end of the leads from the LED strip to the header on the PCB with the first pin (5V +ve) on the right as per the picture above.

Program the Nano with the provided ino file. This is very similar to the code for the Spielatron only the note on function just checks the MIDI value of the note and selects a colour for the LEDs depending on its value.

Blue for notes G5 to D#6, red for notes E6 to B6 and green for notes C7 to G7.

Again there is no code in the note off function as the LEDs are only flashed for 50ms and then turned off by the note on function.

Step 7: Send Music to the MIDI Light Controller

You are now completed and all you have to do is send a piece of music to the MIDI light controller and the LEDs will flash according to their note value. At the end of the video above there is a test piece showing the LEDs changing colour as the Spielatron progresses up and down a chromatic scale.