WS281x LEDs are very simple to wire with their 3 LEDs. There are three options of how to wire, each detailed below.

Raspberry Pi Wiring

The hardest part about wiring with a Raspberry Pi is connecting up the 3.3v logic from the Pi to the strip that wants 5v. There are several ways you can do this, which are described in more detail below.

No Level Shifting

It is possible to connect the LEDs up without any kind of level shifting, however mileage varies from strip to strip. I have one setup like this, and one with the full logic shifter. This can work because the spec of the LED strips means they need 0.7 * VDD(5v) which is ~3.5v. Close to the Pi's 3.3, so depending on how tight of a tolerance your strip has, this is possible.

Wiring is as follows:

• Pi GND to LED GND

• Pi to LED Data in

• Power supply GND to LED GND

Level Shifting Chip

You can use a level shifting chip to convert the signals from 3.3v to 5v. Recommended one to use is a 74AHCT125, I have this and it works well.

Wiring of this is as follows:

• Common ground between:

  • Pi GND

  • LED GND

Wiring with a Diode

The diode method is a quick way to reduce the power supply voltage slightly, so that the LED strip can read the 3.3v.

Wiring is as follows:

• Pi to LED Data in

• Power supply 5V to 1N4001 diode anode (side without the stripe)

• 1N4001 diode cathode (side with the stripe) to LED 5V

On to the next stage: SPI setup

The plugin uses the Raspberry Pi's SPI interface to push data to the LED strip, rather than PWM since it doesn't need to be run as root to use SPI.

As a result of this, there are a couple of OS level configuration items that need to be handled. Luckily for you, the plugin makes this very easy for you to do by providing a UI to run the commands.

Initial Setup Wizard

The setup wizard requires root access, and therefore the password for the Pi user if you have not configured passwordless sudo, as is default on OctoPi. This password is not stored, and is only used for the steps below.

• Add the pi user to the gpio group.

  Already configured on newer images. Means the pi users can access the GPIO pins.

Final stage: Initial Configuration

This documentation should tell you all you need to know about how to use the plugin. There's a lot of information here, please be sure to read some of it before opening issues in case the solution is here.

I've tried to make this setup process as simple as possible, while it was already easy it is even easier with this guide.

Installation

Install the plugin via OctoPrint's bundled plugin manager or manually using this URL:

Once you have installed and enabled the plugin, OctoPrint will prompt you to restart the server.

Check you have the right hardware:

Next up: Wiring your LEDs

The plugin needs to be able to access 3 files to run. These are:

• /boot/config.txt

• /boot/commandline.txt

• /proc/device-tree/model

It also needs access to the underlying hardware to drive the LEDs. To do this it will need to run privileged with docker.

Add the following mappings to docker-compose.yml under the volumes: section of the OctoPrint service

To enable access to the hardware to drive the LEDs, the container must be run privileged:

The final file should look something like this Gist:

LED Strips

The 3 types of LED strips that the plugin supports are:

• WS2811 (including B variants)

• WS2812 (including B variants)

• SK6812 RGB

• SK6812 RGBW

Please note as well that 'NeoPixels' are an Adafruit brand name, I find that they are much cheaper direct from China with just as good results, they are the same thing.

Power Supplies

There are no officially-supported models for power supplies, since they are all the same. However, please make sure you are using an external power supply and not using the RPi GPIO pins to power the LEDs. They cannot provide the power drawn by a strip of WS281x LEDs.

Don't use tiny wires to connect the LEDs - these can heat up and melt if they are too thin.

Level Shifting

I have had good results with a 74ACHT125 level shifter, which is recommended by Adafruit for their Neopixels. Please note that while WS281x LEDs work without level shifting, you may need to keep the wires as short as possible - especially when using 12V LEDs.

On to wiring it all up!

Each progress effect has some standard options, to customise them. Individual effects have additional options, listed alongside them.

Standard Options

• Enabled

• Progress Colour The colour to indicate the progress of whatever event is happening.

• Base Colour

  The base/background colour of the progress indication.

In addition, there are two global options:

• Reverse the direction of the progress bar

• Base temperature Heating/cooling progress bar will make '0' the temperature specified. Suggested value is just below room temperature, so that the progress bar starts closer to the end of the strip.

Events

Printing Progress

Matches the progress bar in OctoPrint's UI, on your LED strip.

Heating Progress

Triggered when a blocking heating command (M109 or M190) sent to the printer.

Additional options:

• Index of tool to track Leave this at 0 for single extruder printers, for multiple extruder printers you can choose a single tool to track.

• Enable tracking tool heating

• Enable tracking bed heating

Cooling Progress

Triggered on print success, this will display the progress of the printer while it is still cooling.

Additional options:

• Track cooling on bed or tool Select one, since they usually cool down at the same time.

• Cooling temperature threshold The temperature when cooling tracking should stop

Open the plugin's entry in OctoPrint's settings interface, and you should be presented with this view:

Click on the 'LED Strip Settings' button in the top right. The key settings you should edit are listed below:

• Strip Type Select the type of strip you have connected to your Pi. Note: This may not be exactly what you were sold, sometimes they send variations. If you have issues, please try similar strip types here.

• Number of LEDs This should be easy, count the number of LEDs you have connected and enter the right number!

• Max Brightness This setting controls the maximum brightness that your LEDs should reach.

For more details on the rest of these settings, please see the

From OctoPrint's documentation:

@ commands (also known as host commands elsewhere) are special commands you may include in GCODE files streamed through OctoPrint to your printer or send as part of GCODE scripts, through the Terminal Tab, the API or plugins. Contrary to other commands they will never be sent to the printer but instead trigger functions inside OctoPrint.

The plugin reacts to some different @ commands, listed below:

These commands can be used in g-code scripts, or in custom controls in apps - see here for , or the guide on how to create a which also uses @ commands.

Using WS281x LEDs to create a flash for a timelapse

By using the power of it is very easy to make your LEDs react to other plugins that use GCODE scripts. For example, to make the LEDs flash for the timelapse, to light it up, you can use the following settings:

• Enable 'Torch mode is a toggle' in the WS281x LED Status settings, and set the torch effect to solid colour & bright white (and colour will do, but white is the most common!)

The plugin reacts to several events to display printing effects. For each of these effects, they have similar settings:

• Enable Whether the effect will run or not

• Effect One of the available effects

• Colour The primary colour to run the effect. Note this is ignored in some effects.

• Delay The length of time to wait between each frame of the effect.

Some events also have some specific settings, these are detailed alongside them.

Events

• Startup

• Printer Connected/Idle

• Printer Disconnected

Effects

All the standard effects available, with fancy visualisations!

Solid Colour

Sets all LEDs to one colour, forever.

Colour Wipe

Wipes colour across the strip pixel by pixel, then clears it pixel by pixel.

Colour Wipe V2

Wipes colour pixel by pixel, as above, but to clear it turns around and heads backwards.

Pulse

Fades brightness up and down. Looks better in real life than the visualisation below!

Bounce

Sends a pulse of light bouncing from one side of your strip to the other.

Solo Bounce

Sends just a single pixel from one side to the other, bouncing about.

Rainbow

Cycles all the LEDs through the rainbow together.

Rainbow Cycle

Rainbow that cycles across the strip, so a full rainbow is across the whole strip at once.

Crossover

Two pixels bouncing in opposite directions, crossing over in the middle.

Random

Sets all LEDs to a random colour, then changes a random pixel, to a new random colour

Bouncy Balls

A physics based effect, simulating 2 balls bouncing up and down. Looks great on longer strips (and shorter ones too...!).

Unfortunately creating the simulation for this effect didn't work, so is unavailable for now. Sorry!

Please select the area that most describes what you need help with:

LED Strip Test

Press the 4 buttons to check that each segment of your LEDs are working. Useful if the colours are showing wrong, some LEDs don't work or anything hardware related. Each button sets that colour to maximum intensity, to isolate the individual colours.

OS Configuration Test

The popup box will run a configuration test on your OS. It tests for the same things that the , to allow you to verify everything is OK down the line.

At any time, you can run a test of the above settings, using the configuration test dialog. When you run the test, it will tell you if all of the steps are filled in correctly, and if they are not, prompt you to fix it with a click of a button.

This data is also logged to octoprint.log on startup, to help me with diagnosing issues reported to rule out this configuration being the problem.

Power Calculation

Calculates the approximate power consumption of the LED strip. Useful to work out if your power supply is up-to-the task.

The nominal value included by default is 40mA, since this is what I have found to be most common. Brighter LEDs take more power, so adjust to what you think is right for your strips.

This documentation aims to explain all of the settings in the LED Strip Configuration dialog, so you can make the most use of them.

The plugin implements a , which enables external access to the plugin's functionality.

It has a single endpoint, supporting a get request and posting a command.

SimpleAPI Get

GET

Commands should be formatted as such:

M150 [P{intensity}] [R{intensity}] [G{intensity}] [B{intensity}] [W{intensity}]

This is going to be an ever-evolving page, as I learn of common issues people identify when setting up the plugin.

LEDs flicker and change colour loads

Check you have a common ground between an external power supply, and the Pi. See more (including an example video) in the

The colours of my LEDs are wrong

Make sure you have the correct order of RGB strip selected in the strip settings. You can use the LED Strip test to help debug this issue quickly.

Can't find the plugin after installed

Make sure you restart the OctoPrint server, and reload the web interface. You should see the wizard pop up, or the light/torch icon in the navbar.

I restored an OctoPrint backup to a new install, but the LEDs no longer work?

It is likely that the OS level config is incorrect. To fix this, please head to the OS Configuration Test section (under 'Utilities') to run a test and fix the configuration.

Unable to initialize SPI

If you get the error:

From the plugin_ws281x_led_status_debug.log then it likely means that you have some extra peripherals attached to your Pi, that are taking up the SPI channels, therefore conflicting with the plugin's use of SPI.

A user reported that SPI failed to initialise with the above screen, however commenting out the lines the guide asked you to enter meant that both the screen and LEDs could work at the same time.

No LED output on a Raspberry Pi 4B (rev 1.4), and the log says 'Unsupported board'

The dependency that this plugin relies on was not updated to add support for these boards as of the last release of the plugin. Please see for instructions of how to fix it.

Little/no LED output when not using a level shifter

Some strips do not like 3.3V signals, and if you do use 3.3v (without a level shifter) then please keep the wires to the LEDs fairly short to avoid voltage drop.

Random flickering of LEDs, unstable signal

Adding a 470Ω resistor in the signal line can help. Some guides recommend this, in my experience it is not always required. Worth a try if you have unstable signal to the LEDs. .

More unstable signal fixes

Mixed reports that using a sacrificial LED on a short wire (to avoid voltage drop) can be beneficial for the LED strip. See for more details. This solution is untested, only linked because it might be useful.

Here's all the details of the additional features of the plugin, so you can effectively configure them.

Torch

The torch button can be turned on or off to clear up navbar space if you don't want it. It has the same settings as standard effects but with some added extras for a manual trigger.

Using @ commands to trigger the torch can enable cool integrations with other software, such as OctoLapse.

Toggle Mode

The torch button or turns the torch on permanently, until it is turned off. This blocks any other effects.

Timed Mode

The torch button starts a timer to turn off after configurable length of time.

Active Times

The LED strip will turn on at the start time, off at the end time. Potentially useful if you don't want them on overnight.

M150 Intercept

Enable intercepting and using M150 commands. If not checked, these commands will be sent to the printer.

For documentation of the command, please see the

Debug Logging

Debug logging logs a lot more information about the effect runner process. This will help massively when reporting issues on Github, so please enable it when reporting issues!