Alfa Giulia / Stelvio Dashboard Interface

A real-time telemetry interface for Alfa Romeo Giulia / Stelvio dashboards using two MCP2515 CAN modules. It streams live data from sim racing titles to a genuine OEM cluster over CAN bus, replicating factory behavior with high accuracy.

---

🚗 Features

• ✅ Full support for Alfa Romeo Giulia / Stelvio OEM instrument clusters
• ✅ Compatible with both Arduino and STM32 platforms
• ✅ Dual CAN bus architecture:
  • 500 kbps — Powertrain CAN (primary signals, gauges, warnings)
  • 125 kbps — Infotainment / IHS CAN (display, messages, auxiliary data)

---

🎮 Supported Simulators

Simulator	Protocol
BeamNG.drive	OutGauge + Mod
Assetto Corsa	Shared Memory

---

🧱 Architecture Overview

Component	Description
Python Script	Reads telemetry from the game and streams structured data over serial
Arduino / STM32	Parses incoming data, applies mapping logic, and transmits CAN frames
MCP2515 #1	CAN @ 500 kbps — mandatory (powertrain bus: gauges, warnings, core signals)
MCP2515 #2	CAN @ 125 kbps — optional (IHS bus: display, text, auxiliary functions)

---

🔌 Serial Protocol (PC → MCU)

ASCII lines in format {KEY[VALUE]}, one per line.

Example:

{RPM[3100]}
{VEL[88]}
{TMPOLIO[64]}
{CARB[54]}
{MARCIA[3]}
{MEDIA[Best Lap: 1:45.872]}

---

📁 File Structure

📁 Alfa-Romeo-Giulia-SimRacing.zip        --> Arduino / STM32 code
📁 Python.zip                             --> Games Support / Windows
📁 ARG_SimR.zip                           --> BeamNG Mod*

*place ARG_SimR.zip in

C:\Users\%User%\AppData\Local\BeamNG\BeamNG.drive\current\mods

or equivalent folder

---

🔧 Software Requirements (Board Side)

• Arduino IDE
• Supported Boards: Arduino all variants
• MCP2515 Library: MCP_CAN by coryjfowler

Installation Steps

1. Open Arduino IDE
2. Go to Sketch → Include Library → Manage Libraries...
3. Search for "MCP_CAN by coryjfowler"
4. Click Install

---

📦 STM32 Arduino Support (Only for STM32 Boards)

1. Open Arduino IDE
2. Go to File > Preferences
3. Add this URL to Additional Board Manager URLs:

https://github.com/stm32duino/BoardManagerFiles/raw/main/package_stmicroelectronics_index.json

4. Go to Tools > Board > Boards Manager

5. Search for STM32 and install:

   • STM32 MCU based boards by STMicroelectronics

6. 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

---

🔧 Config.h — Firmware Configuration

This is the only file you need to edit to adapt the firmware to your setup.

Platform Selection

#define STM32

Uncomment if using STM32. Leave commented for Arduino.

Optional CAN Module

#define CAN2_OPTIONAL

Enable second CAN bus (IHS).

⚠️ STM32 users must physically disconnect the unused CAN2 module or it may cause SPI instability.

Optional Features

// #define MY23   // For 2023 clusters (shift light handling)
// #define SHIFT  // Enable shift light for 7" TFT only

#define LEVEL_1 5400 // rpm value
#define LEVEL_2 5900 // rpm value
#define LEVEL_3 6400 // rpm value

• MY23: enables dedicated handling for Giulia/Stelvio MY2023 clusters.
• SHIFT: enables shift light display on 7" clusters (do not use on 3.5").
• LEVEL_*: defines the 3 available shift warning levels on 7" clusters. Requires RACE mode enabled on the cluster (via PROXI alignment).

Leave them commented unless you need these features.

CAN Bus Settings

#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).

Send Interval

#define SEND_INTERVAL 0

Set to 0 for maximum throughput (recommended). Increase only for debugging or bandwidth issues

---

🔌 Pin Definitions

STM32 (F401CCU6 Black Pill)

// 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

Arduino (e.g., Uno, Nano)

// CAN1
#define CAN1_CS_PIN 10
#define CAN1_INT_PIN 2

// CAN2 (optional)
#define CAN2_CS_PIN 9
#define CAN2_INT_PIN 3

---

🧪 Python Serial Communication

• Python 3.10+
• pyserial

Install with (in Powershell):

pip install pyserial

---

🐍 Python Serial Communication Setup

To 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

---

⚙️ Hardware Setup

Required Components

• ✅ STM32 or Arduino
• ✅ 2x MCP2515 CAN modules (TJA1050) (120Ω termination enabled — jumper or soldered pins)
• ✅ Alfa Romeo Giulia / Stelvio OEM instrument cluster (well… obviously)
• ✅ 12V power supply
• ✅ Wiring and connectors

🔌 Connector Pinout

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 (same for 13 and 14).

• You can use either pin in each pair — CAN A/B pairing order does not matter.
• I use a variable power supply set to 14.4V, but any source in the 12V–16V range works fine.

• If you don’t have the original OEM cluster connector, it’s not an issue.
  Standard Dupont jumper wires or 2.54mm pitch connectors (2× 1x6) work reliably without major problems.

🔌 SPI & CAN Wiring (STM32)

🧩 Shared SPI Bus

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

🔧 Chip Select & Interrupts

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.

---

🔌 SPI & CAN Wiring (Arduino Nano)

🧩 Shared SPI Bus

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

🔧 Chip Select & Interrupts

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.

---

✅ Tested With

• BeamNG.drive
• Assetto Corsa
• Alfa Romeo Giulia OEM cluster (2017 and 2020)
• STM32F401CCU6 (Black Pill)
• Arduino Nano
• Dual MCP2515 modules (8 MHz, TJA1050, 120Ω termination)

---

🧪 Feature Support

Feature	Can Bus
RPM	CAN1 – BeamNG / Assetto Corsa
Speed	CAN1 – BeamNG / Assetto Corsa
Oil Temperature	CAN1 – Assetto Corsa / BeamNG (possible mismatch due to static OEM map)
Fuel Level	CAN1 – BeamNG / Assetto Corsa
ABS Light (lamp)	CAN1 – BeamNG / Assetto Corsa
ABS Active	CAN1 – BeamNG / Assetto Corsa
ESC Light	CAN1 – BeamNG / Assetto Corsa
ESC Active (TC/ESP)	CAN1 – BeamNG / Assetto Corsa
Handbrake Light	CAN1 – Only BeamNG
Battery Light	CAN1 – Only BeamNG
Check Engine (MIL)	CAN1 – Only BeamNG
Left Indicator	CAN2 – Only BeamNG
Right Indicator	CAN2 – Only BeamNG
Position Lights	CAN2 – Only BeamNG
Low Beam	CAN2 – Only BeamNG
High Beam	CAN2 – Only BeamNG
Front Fog Lights	CAN2 – Only BeamNG
Rear Fog Lights	CAN2 – Not currently driven by scripts
Auto Lights	CAN2 – Not currently driven by scripts
DNA Mode	CAN1 – BeamNG / Assetto Corsa (limited: Race/Normal only)
Shift Light	CAN1 – BeamNG / Assetto Corsa
Current Gear	CAN1 – BeamNG / Assetto Corsa
External Temperature	CAN2 – Assetto Corsa / BeamNG (BeamNG is static 20°)
MEDIA	CAN2 – Assetto Corsa (Best lap, or current if unavailable) / BeamNG (dummy)

⚠️ When the cluster is in RACE profile, MEDIA and External Temp are not shown on 7" displays — this is OEM behavior.

ℹ️ The optional second CAN module (IHS) helps prevent odometer blinking by supplying additional messages expected by the cluster.

My glorious Setup:

---

⚠️ Known Notes

• General:

  • On first cluster power-up, a handbrake system fault warning may appear.
    This is expected and will clear automatically after a few seconds.

  • The following signals depend on game support:

    • Primary lights (indicators, headlights, fog lights) → available only in BeamNG
    • Battery / Check Engine → available only in BeamNG

  • The following values are approximated:

    • Oil temperature (Assetto Corsa) → derived from water temperature
    • DNA (Assetto Corsa) → simplified (Race / Normal only)

• BeamNG.drive:

  • Requires OutGauge enabled

  • Fully supported:

    • Primary lights
    • Secondary warnings (ABS, ESC, handbrake, battery, MIL)
    • Gear, RPM, speed, fuel, DNA

  • Limitations:

    • **Oil temperature may have a mapping mismatch
    • External temperature is not transmitted

• Assetto Corsa:

  • No plugin required — uses shared memory

  • Supported:

    • Core telemetry (RPM, speed, gear, fuel)
    • Secondary warnings (ABS, ESC)
    • External temperature
    • Lap time via MEDIA

  • Limitations:

    • No primary lights support (indicators, headlights, fog lights)
    • No handbrake / battery / check engine signals

---

☕️ Like the project? Buy me a coffee!
Your support helps keep clusters alive and CAN buses busy.

📜 License

MIT License — Use at your own risk.
Not affiliated with Alfa Romeo, FCA, or Stellantis.