Why does nothing turn on in my arcade cabinet?

Check that 18650 batteries are installed correctly in the UPS HAT. Verify the DPDT power button is toggled ON. Plug USB-C into the HAT and check if D1-D4 LEDs light up.

How does the UPS HAT power the Raspberry Pi?

The MakerFocus UPS HAT plugs directly onto the Pi's 40-pin GPIO header and provides regulated 5V through the 5V and GND pins. No separate USB cable is needed between the HAT and Pi.

What is retrogame and how do I configure it?

Retrogame is Adafruit's utility that maps GPIO pins to keyboard key presses. Create /boot/retrogame.cfg with your GPIO-to-key mappings. It runs as a daemon and emits keyboard events that emulators read as controller input.

Why is a single button not responding?

Check solder joints on the tactile switch legs. Verify the signal wire goes to the correct GPIO pin. Test by shorting the GPIO pin to GND with a jumper wire.

Why are all my buttons unresponsive?

Check the GND daisy chain is connected to a Pi GND pin. Verify retrogame is running: 'ps aux | grep retrogame'. Check /boot/retrogame.cfg exists and has correct GPIO numbers.

What GPIO pins are used for the joystick?

UP=GPIO 17 (Pin 11), DOWN=GPIO 27 (Pin 13), LEFT=GPIO 22 (Pin 15), RIGHT=GPIO 23 (Pin 16). Wire each micro lever switch NO terminal to its GPIO pin and COM to GND.

Why are my joystick directions swapped?

The joystick may be mounted rotated. Swap the offending wire pair at the GPIO header, or update the GPIO numbers in /boot/retrogame.cfg.

How do I wire the coin door LEDs?

Wire each blue LED anode through a 100-150 Ohm resistor to 5V, cathode to GND. The LEDs stay always-on when the system is powered. The switch contacts wire separately to GPIO 16 and GPIO 20.

How do I fix buzzing from the speakers?

Ensure the Pi and PAM8403 share the same ground. Route audio wires away from GPIO signal wires. Add a 100µF cap across the amp's VCC and GND.

What does the DPDT power button do?

The latching DPDT switch is wired inline with the battery positive lead. Toggling it breaks or connects the battery circuit, providing a clean power on/off without unplugging anything.

LEARN TO WIRE YOUR ARCADE

Step-by-step interactive guide: USB-C → UPSPack V3P → Raspberry Pi → Buttons, Joystick & Marquee. Click each step to see the wires light up.

BEFORE YOU START

Required Tools

• Wire strippers (for prep)
• Crimping tool or soldering iron
• Multimeter (for testing)
• Small Phillips screwdriver
• Labels or colored tape

Safety Basics

• Work on a hard, non-carpeted surface
• Touch a metal object first to discharge static
• Power off before connecting/disconnecting wires
• Never force a connector — if it doesn't fit, check orientation
• Keep the LiPo battery away from heat and sharp objects

BUILD PROGRESS: 0/9 STEPS

Pinch to zoom · Drag to pan

Click a lesson step to highlight that section of the circuit

LEARN TO WIRE YOUR ARCADE

BEFORE YOU START

POWER SETUP — UPS HAT

MOUNT UPS HAT ON PI

DPDT POWER BUTTON

CONNECT THE DISPLAY

WIRE CONTROL PANEL BUTTONS

WIRE THE JOYSTICK

WIRE COIN DOOR BUTTONS

WIRE THE MARQUEE

SET UP AUDIO