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2. Hardware Analysis

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Spb2005 edited this page Feb 16, 2026 · 6 revisions

Overview

This section documents the hardware architecture of the Thrustmaster T248 steering wheel and its related components.

Focus areas:

  • Internal PCB structure
  • Microcontroller pin usage
  • Peripheral devices (encoders, screen, shifters)
  • Wheel-to-wheelbase connection
  • Pedal set

Wheel Disassembly

Warning: Disassembly requires force. Take care not to strain or rip the cable.

Steps:

  1. Remove the wheel by unscrewing the 2 screws securing it to the shaft.
  2. Additional screws: 20 large screws and one small screw secure the red band. One screw is hidden beneath the front red band.
  3. Carefully disassemble the wheel; the cable can be detached from the PCB if needed.
  4. Backside components: magnetic shifters, cable, and connectors. For custom connections, consider using a 6-pin Picoblade connector.
  5. Frontside components: PCB, encoders, and display.

Steering Wheel PCB

The wheel PCB uses an STM32G030K6 microcontroller. I have completely reverse-engineered the PCB and its schematic. Note that the PCB layout is not entirely accurate or to scale.

Main Components

  • Rubber dome buttons
  • Hall-effect shifters
  • Push button encoders
  • I²C display module (Vinka VK2C23B)
  • UART interface to wheelbase
  • Reset line control
  • Debug/programming pads

PCB Images

PCB Front
PCB Back
Front PCB Design
Back PCB Design

Key PCB Details

Feature Details
Microcontroller pins All pins used; PB3 only with 100Ω pull-down
LED Connected to PB5
Debug Port NRST, SWCLK (PA14), SWDIO (PA13), 3.3V, GND
Display (I²C) SDA → PA12, SCL → PA11 via 27.5Ω, pull-ups 4.7kΩ, EDK tied to GND
Hall Sensors PB7, PA4
Rubber Dome Buttons PA0, PA1, PA8, PA9, PA10, PA13, PA14, PA15, PB0, PB1, PB2, PB4, PB6, PB8, PB9, PC14, PC15
Encoder Buttons PA5, PA6, PA7, PC6
Wheel Connector 3.3V, GND, PA14, PA3 (RX), PA2 (TX via 27.5Ω), NRST (via N-MOSFET)

Debug Port

  • Used for STM32 programming via SWD
  • Access may require special debug state, see Firmware Analysis
  • Firmware might be read out protected

Schematic

Display Connections

  • Controller: Vinka VK2C23B
  • Lines: SDA, SCL, EDK (GND), 3.3V, GND
  • Screen data originates from wheelbase via UART and is forwarded internally over I²C
  • Full decoding is still in progress

Schematic

Hall Sensors & Shifters

  • Connected to PB7 and PA4
  • Magnetic shifters detect paddle position without mechanical contact

Wheel Connector

6-pin Picoblade connection to wheelbase:

Pin Function / Notes
3.3V Power supply
PA14 Shared with Mode button; potentialy used for firmware update
RX (PA3) Data from wheelbase
TX (PA2) Data to wheelbase (series resistor 27.5Ω)
GND Ground
RESET inverted via N-MOSFET, used in startup

Wheel Connector

Encoders

  • Two pushbuttons per encoder actuated by lever
  • Tactile feedback adjustable via rear screw

Screen

  • Custom I²C LCD (Vinka VK2C23B)
  • Connections: 3.3V, GND, SDA, SCL, EDK → GND
  • Datasheet available from manufacturer (Chinese, Google Lens usable)

LCD

  • Screen receives data from wheelbase via UART
  • Forwarded internally over I²C
  • Decoding incomplete

Pedal Set

  • Model: T3PM (successor to T3PA)
  • Hall effect sensors instead of potentiometers
  • Uses analog 0–3.3V signals via RJ12 connector
  • Works with T248 wheelbase

T3PM Pedals

Wheelbase

  • Microcontroller: STM32L412CB, 128 KB Flash
  • Function: Motor driver, FFB processing, USB interface
  • Wheelbase acts as UART master

Disassembly not performed; reference material:

Read Next

For protocol-level analysis:

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