Open-source macOS/Linux driver for SM2 Pro J2534 CAN adapters (Scanmatik).

The SM2 Pro is a professional automotive diagnostic adapter that officially supports only Windows. SM2CAN provides native macOS and Linux support via clean room reverse engineering of the USB wire protocol.

pip install sm2can

macOS also needs libusb:

brew install libusb

import can

bus = can.Bus(interface='sm2', bitrate=500000)

# Receive
msg = bus.recv(timeout=1.0)
if msg:
    print(f"0x{msg.arbitration_id:03X}: {msg.data.hex()}")

# Send
bus.send(can.Message(arbitration_id=0x7DF,
                     data=[0x02, 0x01, 0x00, 0, 0, 0, 0, 0]))

bus.shutdown()

from sm2can import SM2Device

dev = SM2Device()
dev.open(bitrate=500000)

dev.send(0x7DF, bytes([0x02, 0x01, 0x00, 0, 0, 0, 0, 0]))
frame = dev.recv(timeout=1.0)

dev.close()

sm2can probe              # Detect device, test echo, show firmware info
sm2can info               # Show device info
sm2can monitor            # Live CAN bus monitor
sm2can monitor -l         # Listen-only mode
sm2can send 7DF 0201000000000000   # Send a frame
sm2can echo               # Health check

sm2can-sniff                          # Sniff all CAN traffic
sm2can-sniff --steering               # Only steering IDs (MDPS, SAS, LKAS)
sm2can-sniff --filter 251,2B0,340     # Custom ID filter
sm2can-sniff --inject                 # Sniff + inject passive LKAS11 probes
sm2can-sniff --log capture.csv        # Log all frames to CSV
sm2can-sniff --duration 30            # Auto-stop after 30 seconds
sm2can-sniff --quiet                  # No live output, summary only

Decodes: MDPS12 (steering torque), SAS11 (steering angle), LKAS11 (LKAS commands), CLU11 (vehicle speed), WHL_SPD11 (wheel speeds), TCS13 (traction control), EMS11 (engine RPM). Includes steering system analysis at exit.

The wire protocol was reverse engineered from the official Scanmatik Android APK and confirmed via live hardware probing.

Frame format:

[CMD, LEN_LO, LEN_HI, CHECKSUM, ...PAYLOAD]

Checksum = (CMD + 0x55 + LEN_HI + LEN_LO) & 0xFF

USB identifiers: VID 0x20A2 PID 0x0001, bulk endpoints 0x02 (OUT) and 0x81 (IN).

See SM2_PRO_PROTOCOL_SPEC.md for the complete protocol specification.

• SM2 Pro adapter (Scanmatik)
• USB cable
• Vehicle connection for CAN bus operations (12V on OBD-II pin 16 powers the vehicle side, but the SM2 Pro itself boots on USB 5V)

This project uses clean room reverse engineering to achieve interoperability with legitimately purchased hardware. No proprietary code, firmware, or documentation was used. See LEGAL.md for details.

MIT — Copyright (c) 2026 Aldo Guzman