Tentacle Buddy & Breakout Guide

Overview

Tentacle Buddies help you wire up projects with strands of LEDs that
dangle from a central ring (like tentacles) or hang from horizontal
strips (like curtains). The Tentacle System consists of 2 boards: the
Tentacle Buddy and the Tentacle Breakout. It's optimized for a
Pixelblaze Pico though they can be used with any LED controller, and for
Pebble-style strands with a Data Return line. They help keep your LED
data wiring tidy and compact, make connectorizing strands and
controllers easy, and also feature a convenient USB-C connector for
powering both the LEDs and controller.

Click the dropdowns below for more information on how to hook them up!

Controller Option 1 - Direct Soldering to a Pixelblaze Pico

This board can solder directly to the back of a Pixelblaze Pico to make a very compact form factor.  

First, cover the back of the Pico with tape (we like kapton best for this) to insulate the exposed pads on the back of the Pico.
Next, solder the Pico and the Buddy together using the castellated edges.

Controller Option 2 - Connectorizing for a Pico or any LED Controller

Alternately, you can use the enclosed right angle 0.1" headers to connect the Pico to the Buddy.  Since the Buddy provides power, we prefer using the sockets on this side, and the pins on the Pico/controller side.  But you can do whatever works best for your project.  You could even use a straight header (not provided) and plug the Buddy directly into a breadboard.   For LED controllers with a different pinout than the Pico, you can solder wires to the Buddy, or wire the included headers in whatever pinout you need.

Adding the LEDs

Tentacle Buddies are designed to use Pebble strands that have a "Data Return" line, which makes it easy to create a project that has several dangling strands of LEDs (like curtains, or having several strands that go down a skirt from the waistband, or .... tentacles!).  The Data Return line is simply an extra wire, not connected to anything on the strand.  When you cut your strand to the length needed for your project, leave a small bit of wire after the last LED.  You'll strip and solder the wires from the Data Out of the last LED to the Data Return line.  This brings your LED data back up to the very top of the strip, and back to the Buddy board.  We've then routed this to the side LED output pads, so you can keep the chain going.  You can connect a standard 3-pin strand here to carry the chain around, or you can connect a Data Return strand and ignore the Data Return line, or you can just use wires.  To make it even easier to keep daisy-chaining LEDs and tentacles, we've also made the Tentacle Breakout boards (see below).

LEDs Option 1 - Direct Soldering a Pebble Strand

Find the Data In side of your Pebble strand with Data Return, and strip the wires back.  Solder them directly to the pads coming out of the bottom of the Buddy, with the Pebble lens facing up.  You can tell which side is "up" because it will have a more pronounced bump than the "back" side.

Next, cut your Pebble strand to the length you want, leaving enough wire coming out of the last LED for you to strip and splice it.  Strip the Data Out and Data Return wires, and solder them together.  You may want to cover the splice with clear heat shrink so it doesn't accidentally short to anything else.

LEDs Option 2 - Connectorizing

This option allows you to easily remove the controller or strips from your project.  

First, solder the included JST connector to the Buddy.
Next, solder the included JST pigtail cable to your LEDs.  You can cut the cable and strip the wires if you need a shorter length.  The cable will solder to Pebble strands 1:1, meaning no wires will be crossed if your Pebble strand is lens-side-up and the connector is oriented so it plugs straight into the Buddy.  Also note that the 5V wire is marked on all Pebble strands we sell.

Repeat for the side connector to attach more LEDs.
Don't forget to terminate each tentacle so that your Data Return wire brings the data back up to the Buddy (see Option 1).

Option 1 - Direct Soldering to Pebble strands with Bare PCBs

This is an option for the unpopulated flex or rigid PCBs.  The data enters the Tentacle Breakout on the left side, is routed down to the Tentacle pads on the bottom, and then goes out the pads on the right side.  

Attach your incoming LED data.  If it's coming from another Pebble strand, strip and solder the wires on the Data Out side of the strand to the pads on the left side of the Tentacle Breakout board.  If using the flex PCB version, be efficient and quick when soldering as these are not quite as heat-resistant as rigid boards.  Use flux!  The soldering should be 1:1 Pebble to pads as long as the Pebble lenses are facing up.  The marked wire on the Pebble strand is 5V.  The markings on the PCBs correspond to:

+ = 5V

D = Data

- = GND

DR = Data Return


Attach your Tentacle.  Find the Data In side of your Pebble strand with Data Return, and strip the wires back. Solder them directly to the pads coming out of the bottom of the Buddy, with the Pebble lens facing up. You can tell which side is "up" because it will have a more pronounced bump than the "back" side.


Terminate your Tentacle.  Cut your Tentacle to the length you want, leaving enough wire coming out of the last LED for you to strip and splice it. Strip the Data Out and Data Return wires, and solder them together. You may want to cover the splice with clear heat shrink so it doesn't accidentally short to anything else.


Attach your outgoing LEDs (or wires).  The LED data from the last LED on the Tentacle is routed to the pads on the right side of the PCB.  You can attach wires, a standard 3-pin LED strand, or another Data Return style strand leaving the Data Return line unconnected.  Make sure you strip and solder the Data In side of that strand.


Alternate: Skip the Tentacle.  There's also a small solder jumper in the center of the board.  Bridging these pads with solder will skip the downward tentacle, and route the data coming in on the left to the data going out on the right.  It can be a little easier than trying to splice Pebble wires together, especially for strands with small 15 or 20 mm pitches.  With the flex circuits, you can also just cut off the downward Tentacle pads completely.

Option 2 - Connectorizing to Pebble strands with Populated Rigid PCB

This is an option for the rigid PCBs that already have the connectors populated.  It's handy if you want to be able to easily remove or replace strands.
All you'll need to do is splice the provided pigtails to your Pebble strands.  There is 1:1 signal mapping if your strands have the lenses facing up, and the connector is in the orientation to plug directly into the board.  Note that we have put a 3-pin connector on the left input side and a 4-pin connector on the right output side.  Why?  This is so if you remove a strand that connects two Tentacle breakout boards, it's not possible for you to accidentally rotate it 180, and then plug it in backwards.  (This would be possible if both connectors on each side were the same.)


Don't forget to follow the instructions above to terminate your Tentacle strands so that the Data Return line carries the LED data back up to the PCB.

Plug in a USB power source

If you've followed all of the instructions above, have connected an LED controller and all of your LEDs, just plug in a USB-C power source and you're ready to go!  This will power both the controller and the LED strands.  If you need to inject power at any point, the Tentacle Breakouts make that pretty easy.  Just leave the 5V line from the incoming LED strip unconnected, and insert 5V there.  Solder the GND for the new power supply to any GND point on the board.

Downloads

How to download our BOM from GitHub:
1. Click the BOM button above
2. Right click over the raw data
3. Select save as and save the CSV file
Have any questions?  Contact us!