Slice with settings for PLA material

The parts were sliced using BambuStudio using the slice settings below.

• PLA filament 220c extruder
• 0.2 layer height
• 15% grid infill
• 200mm/s print speed

Download Firmware

There isn't an official build for the QT Py RP2040 yes, but you can use this pre-release version by clicking the GP2040-CE_0.7.12_AdafruitQTPyRP2040.uf2 file.

This will save a file named GP2040-CE_0.7.12_AdafruitQTPyRP2040.uf2 to your download location.

Firmware Installation

This page gives detailed instructions on installation, but the basic steps are:

• Plug the QT Py RP2040 into your computer with a known good data and power USB cable
• While holding the BOOTSEL button down, press and release the RESET button this puts the board into BOOTSEL/USB drive mode
• A new removable drive named RPI-RP2 will appear on your computer
• Drag-and-drop the GP2040-CE_0.7.12_AdafruitQTPyRP2040.uf2 (or later) firmware .uf2 file onto the RPI-RP2 drive and wait for it to copy the file and reboot itself

Pin Mapping

The default pin mapping in GP2040-CE for the QT Py RP2040 is shown here.

Button Test

This is a great time to test the controller to make sure basic button presses are working.

Plug the QT Py RP2040 into your computer with a known good USB-C data and power cable. Head to this gamepad tester in your browser to see the button presses.

You can now use a jumper wire to short any mapped GPIO pin to ground -- those button presses will register on the controller tester. 

Solder the QT Py Headers

Solder the male header pins on to the QT Py RP2040 as shown here.

You can optionally use short headers for a slightly lower profile, but the default pins included with the QT Py work just fine.

See the guide How To Solder Headers for how-to and tips.

Mount the Terminal Block BFF to the Case

Mount the Terminal Block BFF with the larger battery JST connector facing up as shown. Screw the M2.5 x 10mm screws in from the top into standoffs or nuts on the inside of the case.

Use a small slotted screwdriver to open all of the terminal positions by unscrewing them counter clockwise in prep for wiring later.

Add QT Py

Press the QT Py into the terminal block BFF with the USB port facing up as shown.

Arcade Buttons

Insert an arcade button into to the case from the top and then screw on the retaining nut.

Repeat this for the remaining buttons.

Cable Prep

Prepare the cables by first cutting off the white plastic JST connectors (be sure to keep the terminal connector ends intact), thereby separating each pair into two individual cables.

Then, strip about 4mm of insulation from the bare end of each cable.

Twist the wire strands so they don't fray and potentially short against neighboring pins when inserted into the terminal block later.

Repeat these steps for all remaining wires for a total of 22 (that's two wires per button).

Connect Button GPIO

Following the diagram carefully, wire one terminal of each button to it's associated pin on the QT Py via the Terminal Block BFF.

First, press the cable's crimp connector onto one of the button's two switch terminals (these are the two at the top of the switch, not the one's at the bottom with the arrows and +/- signs, those are for the LEDs, which we won't be using).

Then, run that wire through the case and to the terminal block pin for that button. Screw the terminal screw down tight.

Repeat for remaining 10 buttons.

Ground Run

Cut a 20cm length of 22AWG stranded wire (this spool set is handy to have around), then strip about 4mm of insulation from each end.

Feed this wire through the case and into the GND position on the QT Py/BFF. Screw it in place.

Then, inside the case, connect the other end of this wire to any position on the 3-wire block connector.

Chain together all of the block connectors using 6cm lengths of stranded wire with 4mm of insulation stripped from each end.

Cover Lots of Ground Fast

Now you can press the remaining 11 crimp connector cables onto the second switch position of each arcade button (again, avoiding the lower two LED legs).

For each button's ground wire, connect the free end to any open position on a block connector.

Case Closed

Press fit the bottom onto the case as shown.

GPIO Pin Mapping

Click Configuration > GPIO Pin Mapping to make any changes to the button configuration.

If you do make changes, press Save to commit them on the QT Py's flash memory.

Hotkeys

Click Settings > Hotkey Settings. Here you'll see the default Fn + S2 = S1 Button that I included in the QT Py RP2040 configuration. This is what allows the BOOT button (on QT Py) modifier + the Start button to act as the Select button.

If you want you can add as many other hotkey combos as you like. For example, here I've added Fn + Up = Home Button in order to press the Home/PS/Xbox button.

Remember to hit Save when done.

Input Modes

You can use the leverless controller on a variety of consoles and systems. By default it will present itself as an XInput controller / Xbox 360 controller.

Click Settings > Boot Input Modes to see the assigned input modes that you can pick during startup. Simply hold down the assigned button while plugging in -- e.g., hold B1 while plugging in to Nintendo Switch, B2 for Xinput, B3 for PlayStation 3, or B4 for PlayStation 4. 

Reboot

When you're done changing settings, press the Reboot button in the upper right corner. You'll see a popup that lets you choose the mode into which you reboot: USB BOOTSEL, Web-config (the same mode you're already in) or Controller so you can play!