Guitar Controller

A guitar controller with wired USB cable, such as the RedOctane Gibson X-plorer for Xbox 360 shown in this guide.

Other compatible controllers include:

• Rock Band Fender Stratocaster RB1
• Rock Band Precision Bass

Santroller Configurator

You'll use the latest release of the excellent Santroller Configurator firmware for your operating system to set up the USB Host Feather RP2040.

We'll cover the details in this guide.

SantrollerConfigurator Download

Head to the Santroller GitHub releases page and download the latest release for your operating system. I chose the SantrollerConfigurator-win-Setup.exe for Windows.

Once downloaded, install SantrollerConfigurator.

Feather Prep

Plug the USB Host Feather RP2040 into your computer using the USB C port on the Feather, and a known good USB data & power cable.

Put the Feather into bootloader mode:

• while pressing and holding the Boot button down
• press and release the Reset button
• finally, release the Boot button

After a moment you should see the RPI-RP2 drive appear on your computer.

Initial Configuration

With the Feather now in bootloader mode, the available choices in the SantrollerConfigurator will change. Select the following:

• Device to program: Raspberry Pi Pico (/Volumes/RPI-RP2) or whatever path your computer shows for it
• Connection Method: Adafruit Feather RP2040 USB Adapter
• Device to Emulate: Guitar Hero Guitar
• Enable Fortnite Festival Settings: check this on if you intend to play Fortnite Festival, otherwise leave unchecked for other games such as Clone Hero

Configuration Screen Layout

When the configuration screen opens, you'll see a sidebar with buttons on the left for adding individual settings, saving your settings to the Feather, loading the defaults, and more.

On the right are the current settings and options, which we'll look at in more detail below.

If you change any settings, the Status at the bottom will read "You have unsaved changes, click 'Save Settings' to save them". Click Save Settings on the left sidebar menu and the new updated firmware will be written to the Feather.

Detailed Configuration

Click the Expand All/Collapse All button a couple of times to minimize the info on screen. Then, click the down arrow to the right of a section to reveal detailed settings.

Controller Settings

Here you can pick different instrument controller to emulate, such as a Guitar Hero Guitar vs. Rock Band Guitar, the XInput vs HID Controller for Windows Controller Mode, and more.

For example, you can select XInput if you'll be playing on Windows or HID Controller for most other operating systems.

Presets

You can save your settings as a preset here, especially helpful if you're configuring multiple controllers. You can also download settings files created by community members to load here.

USB Host Inputs

Plug your guitar controller into the Feather's USB A Host port. You'll see "1 Device connected" show up in the Santroller interface. Expand this section with the down arrow.

Input Testing

Check the button mapping now by pressing each button on the guitar controller. You'll see the corresponding entry in the Inputs section light up, such as START, BACK, D-Pad directions, and of course the all important fret buttons and strum bar.

Since we're using USB Host mode (and not wiring buttons to GPIO internally) mappings should "just work" and there aren't any settings to worry about here.

Sensor Calibration

You can also test and calibrate the tilt sensor that's built into the guitar and the whammy bar.

Press Calibrate on either to go through a guided calibration process, or manually adjust the values to change their min/max values and the whammy bar dead zone.

Heat Shrink

You can slide a ~4cm length of heat shrink tubing over the JST PH socket cable's wires to keep them neat. 

Solder Socket

You'll solder on a JST PH socket cable to the Feather RP2040 USB Host so that it's easy to plug and unplug the NeoPixel strip.

These are the connections:

• black wire to GND
• red wire to 3V
• white wire to SCK

Encase It

Feed the socket cable through the opening in the bottom of the snap-on enclosure for Feather RP2040 USB Host, then seat the Feather into place.

Snap on the lid and you're ready to plug in the NeoPixels.

NeoPixel Plug

Connect the NeoPixel strip JST PH plug to the Feather's JST PH socket.

USB Connection

Plug in the USB data/power cable to your computer and the Feather's USB C port so we can upadate the firmwares settings. Plug the guitar USB A cable into the Feather's host port.

Launch Santroller Configurator

Launch Santroller Configurator and select the Feather from the Device to program drop-down menu. It should have the name "Santroller -Raspberry PI Pico - Guitar Hero Guitar".

Then, click the Configure button.

LED Settings

Expand the LED Settings section.

Use these settings:

• LED Type is WS2812 - GRB (you can pick different pixel driver types and color orders if using different LEDS)
• LED Count is 30
• WS2812 Data Pin is GP14 (this pin is labelled SCK on the Feather board)
• Turn off LEDs after inactivity leave this at 0 to disable

LED Mapping

Here's the really fun part -- mapping LED activity to inputs on the guitar controller.

Expand the USB Host Inputs section. Here you'll see all of the controller buttons (this is where we tested inputs before). You'll notice a new section that says "Selected LEDs on WS2812" and that there are now 30 buttons to represent the NeoPixels.

Fret Colors

Scroll down to the Green Fret settings of USB Host Inputs.

Let's light up four NeoPixels as green when this button is pressed.

Click to toggle on 2, 3, 4, 5.

Pick the color swatch for Pressed LED color and set it to a dark green color (this keeps the brightness at a reasonable, non-blinding level!).

To test it out the first time, click Save Settings to write the firmware to the Feather. Then, press the green fret and watch them light up!

The Rest of the Frets (a free band name)

Set the rest of the frets to their numbers and colors as shown here.

You can see we're skipping every fifth NeoPixel so we can assign those to the whammy bar later.

A Guy Walks Into a Strum Bar...

Set up the two strum bar directions the same way -- these are listed as D-pad Up and D-pad Down.

Set the up strum to NeoPixels 26 & 27 and down strum to 28 & 29. All can be any color you like, I picked a cool teal.

Whammy Bar

Head to the Whammy Bar section and select these LEDs 1, 6, 11, 16, 21, 28 as these are the remaining NeoPixel positions that fill in the blanks.

This one is an analog input and the NeoPixels will fade from the released color (black to begin with) to the pressed color (I picked white).

Light the Strap

We'll go punk rock here and use safety pins to connect the NeoPixel strip to the strap. The silicone sheath works great for this, just keep away from any contacts on the underside of the strip.

Feather Connection

You can strap the Feather case to the strap with some velcro or elastic waistband material seen here.

Fabulousness Option

You could get a bit fancy with it and cover the strip with a light permissive material! This 1-3/4" waistband elastic would work well. Stitch this to the strap and remove the safety pins if you want a more permanent solution.