Satisfactory Build Gun Electronics

Drop-in replacement for the electronics of the Satisfactory Build Gun replica. Also works for the 3D printed DIY variant. Built around the XIAO RP240.

Features

• Directional LED effect controlled with the thumb stick
• LED Color can be selected with the thumb stick button
• LED Brightness can be varied with the potentiometer on the end of the handle
• Still runs of two AAA batteries
• Supports both PL9832 5mm LEDs and WS2812 style SMD leds.

Assembly Hints

• Never connect USB-C and Batteries at the same time!
• If using 5mm LEDs you might need to either deepen the holes in the lens or grind down the LEDs a bit to make them fit.
• The thumb stick board assembly is a bit sub-optimal:
  • First, solder the SMD components
  • Solder the pin headers: Put the board on a flat hard surface, insert the pin headers and push the plastic spacer down to the board. Solder the pin headers a flush a possible from the back side and cover the solder joints with some isolating tape. Remove the plastic spacers from the pin headers.
  • Solder the thumb stick: Insert the thumb stick into the board and cut the pins flush, then solder as flush as possible. Again, cover the solder joints with tape.
  • Put the XIAO board on the pin headers, leave a ~1mm gap between the XIAO and the thumb stick board. Solder the pins and cut the pins short.
  • I'd also recommend to leave out the battery connector and solder the wires directly since it interferes with the USB plug.
• If you don't need the potentiometer, bridge POT - and POT C.

Bill of Materials

Reference	Description	Notes
U1	XIAO RP2040
U2	MCP1640T-I/CHY Boost Regulator
U3	PS4 thumb stick	other sticks will probably work too
D1-D5	WS2812B SMD LEDs	alternatively fit D6-D10
D6-D10	PL9832 5mm LEDs	alternatively fit D1-D5
L1	NRS4018T4R7MDGJ 4.7µH inductor
R1	825kΩ 0801 resistor
R2	309kΩ 0801 resistor
R3	470Ω 0801 resistor
C1, C2	10uF 0805 capacitor