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PSP Joystick Expansion Card

The PSP Joystick Expansion Card is a community-designed expansion card that adds an analog joystick and two buttons to a Framework laptop1. Created by Nils Schulte (Schnilz) and published in June 2025, it uses a Sony PSP replacement joystick module that fits within the expansion card form factor with millimeter-level clearance12.

Design​

The card is based on LeoDJ's open-source DongleHider+ expansion card design2. It uses a CH32V003 RISC-V microcontroller (~$0.10 USD) running the ch32fun framework and its software USB stack rv003usb to enumerate as a USB HID gamepad2.

The PSP joystick fits within the expansion card envelope thanks to the Framework laptop's rubber feet providing just enough clearance — even when inserted in the front expansion card slots1. Two tactile buttons sit on the bottom of the card and are accessible from below1.

IMU​

The card also includes a TDK IMU (inertial measurement unit) for motion controls. Schulte ported the official TDK driver to the CH32V003 and added a joystick calibration routine1. The IMU is mapped to axes 3 and 4, making it usable for gaming — Schulte described the IMU-based controls as "awesome" despite the ergonomics of the physical stick being "questionable"1.

Technical Specifications​

SpecificationDetails
JoystickSony PSP replacement analog stick12
Buttons2 tactile buttons (bottom of card)1
IMUTDK inertial measurement unit1
MCUCH32V003 (RISC-V, ~$0.10)2
USB Stackrv003usb (software USB)2
InterfaceUSB HID gamepad2
FrameworkBased on LeoDJ's DongleHider+ design2
SourceSchnilz/FW-EC-PSP-Joy (GitHub)2
LicenseCERN-OHL-W-2.02

Development​

Schulte described the project as starting as a "quick filler project" but going through four revisions before the initial public release1. Framework VP nrp praised it as "amazing" and noted it was the second thumbstick expansion card project, calling this one "much more compact"1.

In October 2025, Schulte completed the IMU driver port and joystick calibration, reporting the card was "quite usable now even for gaming"1.

Community Ideas​

Community members proposed several enhancements1:

  • A Π-shaped design that flips the joystick to the keyboard side for in-hand use
  • A wireless Bluetooth version with a small LiPo battery (feasible given the bottom PCB is largely unpopulated)
  • An ESP32-based wireless variant

Footnotes​

  1. PSP Joystick expansion card — Framework Community (Nils_Schulte, June 2025 – October 2025) ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13

  2. Schnilz/FW-EC-PSP-Joy — GitHub (CERN-OHL-W-2.0) ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10