A real-time telemetry interface for Alfa Romeo Giulia / Stelvio dashboards, using two MCP2515 CAN modules.
It reads live data from SimRacing games and controls a real Alfa Romeo Giulia/Stelvio OEM cluster via CAN bus, closely emulating factory behavior.
- ✅ Full support for Alfa Romeo Giulia / Stelvio instrument clusters
- ✅ Compatible with both Arduino and STM32 platforms
- ✅ Dual CAN Bus communication:
- 500 kbps (Powertrain CAN)
- 125 kbps (Infotainment / IHS CAN)
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| Simulator | Protocol |
|---|---|
| BeamNG.drive | OutGauge |
| Assetto Corsa | Shared Memory |
| Component | Description |
|---|---|
| Python Script | Reads game telemetry, sends via serial |
| Arduino/STM32 | Parses serial data, transmits over CAN |
| MCP2515 #1 | CAN @ 500 kbps (required) |
| MCP2515 #2 | CAN @ 125 kbps (optional) |
ASCII lines in format KEY:VALUE, one per line.
RPM:3100
VEL:88
TMPOLIO:90
CARB:64
MARCIA:3
MEDIA:Best Lap: 1:45.872
📁 Alfa-Romeo-Giulia-SimRacing.7z --> Arduino / STM32 code
📁 Python.7z --> Games Support / Windows
📁 BeamNG_Script.7z --> BeamNG Extended Support*
*unzip in
C:\Users\%User%\AppData\Local\BeamNG\BeamNG.drive\current\mods\unpacked
or equivalent folder
- Arduino IDE
- Supported Boards: Arduino Uno, Nano, Micro
- MCP2515 Library:
MCP_CANby coryjfowler
- Open Arduino IDE
- Go to Sketch → Include Library → Manage Libraries...
- Search for
"MCP_CAN by coryjfowler" - Click Install
- Open Arduino IDE
- Go to File > Preferences
- Add this URL to Additional Board Manager URLs:
https://github.com/stm32duino/BoardManagerFiles/raw/main/package_stmicroelectronics_index.json
-
Go to Tools > Board > Boards Manager
-
Search for
STM32and install:- STM32 MCU based boards by STMicroelectronics
-
Set the following:
| Setting | Value |
|---|---|
| Board | Generic STM32F4 series* |
| Board part number | Generic F401CCUx* |
| Upload method | STM32CubeProgrammer (DFU) |
| Optimize | Smallest (-Os default) |
| C Runtime Library | Newlib Nano + Float Printf |
| USB Support | CDC (generic "Serial" supersede U(S)ART) |
| U(S)ART Support | Disabled (no Serial support) |
| USB Speed | Low/Full Speed |
*STM32F401CCU6 Black Pill, adjust according to your board
This is the only file you need to edit to adapt the firmware to your setup.
#define STM32Uncomment if using STM32. Leave commented for Arduino.
#define CAN2_OPTIONALEnable second CAN bus (IHS).
⚠️ STM32 users must physically disconnect the unused CAN2 module or it may cause SPI instability.
// #define MY23 // For 2023 clusters (shift light handling)
// #define SHIFT // Enable shift light for 7" TFT onlyMY23: activates special handling for Giulia/Stelvio MY2023 cluster.SHIFT: enables shift light display on 7" dashboards, don't use on 3.5".
Leave them commented unless you need these features.
#define MCP1_CLOCK MCP_8MHZ
#define CAN1_SPEED CAN_500KBPS
#define MCP2_CLOCK MCP_8MHZ
#define CAN2_SPEED CAN_125KBPS- Clock frequency of each MCP2515 (typically 8MHz or 16MHz).
- Bitrate of each CAN bus (values for Giulia/Stelvio: 500kbps for CAN1, 125kbps for CAN2).
#define SEND_INTERVAL 0Set to 0 for maximum throughput (recommended). Increase only for debugging or bandwidth issues
// SPI
#define SCK_PIN PA5
#define MISO_PIN PA6
#define MOSI_PIN PA7
// CAN1
#define CAN1_CS_PIN PA4
#define CAN1_INT_PIN PA10
// CAN2 (optional)
#define CAN2_CS_PIN PB12
#define CAN2_INT_PIN PB13// CAN1
#define CAN1_CS_PIN 10
#define CAN1_INT_PIN 2
// CAN2 (optional)
#define CAN2_CS_PIN 9
#define CAN2_INT_PIN 3- Python 3.10+
pyserial
Install with (in Powershell):
pip install pyserialTo interact with the STM32 from your PC, the firmware exposes a USB CDC serial port (COM port).
Use the following parameters in Python script:
| Item | Value | Description |
|---|---|---|
| SERIAL_PORT | "COMx" | Adjust according to your system |
| BAUD_RATE | 250000 | Must match the STM32 USB CDC speed |
- ✅ STM32 or Arduino [i used STM32F401CCU6]
- ✅ 2x MCP2515 with TJA1050 [both with 120Ω jumper, i soldered pins]
- ✅ Real Giulia/Stelvio instrument cluster
- ✅ 12v Power Supply
- ✅ Some wires and connectors
| Pin | Description |
|---|---|
| 1 | Ground |
| 2 | Battery |
| 3 | ACC |
| 5 | BH - CAN A (Low) |
| 6 | BH - CAN B (High) |
| 11 | CAN-C1 A (Low) |
| 12 | CAN-C1 A (Low) |
| 13 | CAN-C1 B (High) |
| 14 | CAN-C1 B (High) |
⚠️ Notes:
- Pins 2 and 3 must be bridged together to +12v.
- Pins 11 and 12 are electrically connected together (same for 13 and 14).
- You can connect either pin in each pair CAN A/B pairing order does not matter.
- I personally supply 14.4V using a variable power supply.
- If you don’t have the original OEM connector for the cluster, don’t worry — it’s not a problem.
Standard Dupont jumper wires or 2.54mm pitch connectors (e.g., 2 pieces 1x6) can be used reliably without major issues.
| STM32 Pin | MCP2515 #1 | MCP2515 #2 | Description |
|---|---|---|---|
| PA5 | SCK | SCK | SPI Clock |
| PA6 | MISO | MISO | SPI Master In |
| PA7 | MOSI | MOSI | SPI Master Out |
| 3.3V | VCC | VCC | Logic power |
| GND | GND | GND | Common ground |
| STM32 Pin | CAN Module | Description |
|---|---|---|
| PB12 | MCP2515 #1 | CS1 (CAN1 - 500k) |
| PA4 | MCP2515 #2 | CS2 (CAN2 - 125k) |
| PB13 | MCP2515 #1 | INT1 (IRQ input) |
| PA13 | MCP2515 #2 | INT2 (IRQ input) |
⚠️ Both MCP2515 share the same SPI bus. Only CS and INT are separate.
| Arduino Pin | MCP2515 #1 | MCP2515 #2 | Description |
|---|---|---|---|
| D13 | SCK | SCK | SPI Clock |
| D12 | MISO | MISO | SPI Master In |
| D11 | MOSI | MOSI | SPI Master Out |
| 5V | VCC | VCC | Logic power (5V) |
| GND | GND | GND | Common ground |
| Arduino Pin | CAN Module | Description |
|---|---|---|
| D10 | MCP2515 #1 | CS1 (CAN1 - 500k) |
| D9 | MCP2515 #2 | CS2 (CAN2 - 125k) |
| D2 | MCP2515 #1 | INT1 (IRQ input) |
| D3 | MCP2515 #2 | INT2 (IRQ input) |
⚠️ Both MCP2515 share the same SPI bus. Only CS and INT are separate.
- BeamNG.drive
- Assetto Corsa
- OEM Giulia cluster (2017)
- STM32F401CCU6 (Black Pill)
- Arduino Nano
- Dual MCP2515 (8MHz, TJA1050, 120Ω)
| Feature | Can Bus |
|---|---|
| Rpm | CAN1 |
| Speed | CAN1 |
| Oil Temperature | CAN1 |
| Fuel Level | CAN1 |
| ABS Light | CAN1 – Only BeamNg |
| ESC Light | CAN1 |
| Handbrake Light | CAN1 – Only BeamNg |
| DNA | CAN1 |
| Shift Light | CAN1 |
| Current Gear | CAN1 |
| External Temp | CAN2 - Realistic in Assetto Corsa, dummy in BeamNg |
| MEDIA | CAN2 - Best Lap in Assetto Corsa, dummy in BeamNg |
⚠️ When the cluster is in RACE profile, MEDIA and External Temp lines on 7" dashboards are not available and cannot be displayed, this is the OEM behavior.
ℹ️ The optional second CAN module (IHS) helps prevent odometer blinking by providing additional messages expected by the cluster.
My glorious Setup:
-
General:
-
On first cluster power-up, a handbrake system fault warning may appear.
This is expected and will clear automatically after a few seconds. -
Development is in progress to remove or map them to game events where possible:
- TPMS (Tire Pressure Monitoring System)
- Power Steering Fault
- Lane Assist / Lane Departure Warning
Headlights
-
The following warnings are suppressed, but not yet synchronized with game logic:
- Airbag
- MIL (Check Engine)
- Clock/Time
Turn Signals / Indicators
-
-
BeamNG.drive:
- Enable OutGauge in the settings menu.
A low fuel alert may briefly appear after respawning.
-
Assetto Corsa:
- No plugin required — uses native shared memory access.
- On the first launch of Assetto Corsa make sure to enter the track at least once before running the Python script.
MIT License — Use at your own risk.
Not affiliated with Alfa Romeo, FCA, or Stellantis.