What is it?

Named after Fajardo, Puerto Rico, where the annual Island of Light Festival takes place, this tiny (0.6"x0.75") board provides a 5kV isolated data connection from controller to LED when each are powered separately.

Any LED system that uses multiple power supplies or batteries can use a Fajardo board to eliminate the need for a common ground, simplifying power system design significantly when the controller must be physically far from the LED location, or when modularizing is needed for larger installations. This board will also allow a multi-output controller to drive LED strings of different voltages up to 30V.

Works with any 1-wire interface addressable digital LED with speeds up to 5MHz, including WS28xx, NeoPixels, etc. LED voltage can be 5-30V.

Input and output connections can be made through soldering either via 0.1" headers or pigtails that match the existing LED strips in the system. Optional set of 4 JST pigtails can be purchased with the Fajardo board.

Why did you make it?

I designed this board to solve the common ground problem I ran into designing the electrical system for the Giant Rainbow Bridge. With 25,000 LEDs evenly distributed over both sides of a 75' wide arch, there was no reasonable way to create a common ground, an isolator board is necessary. As other artists creating light art must run into the same problem, especially when the scale becomes larger, I wanted to design this board to help simplify and reduce cost for the power system design.

What makes it special?

Once you start to level up your light art projects, power system design becomes critical as unsolved ground problems can cause flickering, overheating of unexpected components, and other intermittent issues. Fajardo LED data isolator board is a super handy part of scaling up and modularizing your designs.

Other isolator boards exist but they either require differential input or only operates at a fixed voltage output (typically 5V), because they are made for a different application. Fajardo LED data isolator works with the much more common single ended input from the controller and can be used with 5V, 12V, or 24V addressable LEDs. There's also a status LED which lights up to show that active data is coming in from the controller.

A note about the controller side power domain voltage: outputs from LED controller boards such as PixLite, Pixel Pusher, etc, can be connected as shown regardless of their input voltage because they will always output TTL (5V high) IOs for the data out signal.

If you’re using an Arduino, Raspberry Pi, or other embedded board output pin to drive LEDs, as long as the IO voltage range is 4 - 5.5V, Fajardo will work as designed. If the IO voltage is 3.3V, replace the status LED (D100) on the board with a 120ohm resistor.

Designed by EE with 15+ years experience in consumer electronics industry. Lots of details of board design optimized for debugging and ease of use.