5.1 KiB
5.1 KiB
{canscope}
CAN bus sniffer and SAE J1939 protocol analyzer. Reads CAN frames in candump format, decodes them using a J1939 Digital Annex (xlsx or csv), and presents results in an interactive terminal UI or as JSON output.
Features
- TUI mode - full-screen interactive terminal interface (FTXUI). Multiple display modes per CAN ID: deployed, brief, verbose, manual, little-endian
- Headless mode - JSON output to stdout or file, for scripting and automation
- Recording - decoded J1939 SPN values saved to SQLite database with gzip compression and batch flushing
- J1939 decoding - PGN/SPN lookup, bit-level value extraction from payload. Supports xlsx and csv input formats
- CAN playback - replay recorded CAN frames
- Custom SPN configuration - per-parameter settings, parameter export
- Real-time - 30 fps UI refresh
Build
Requirements:
- clang++ with C++23 support
- CMake >= 3.13
- Ninja
- System libraries: boost (signals2, spirit, phoenix, regex), sqlite3, zlib, icu
Dependencies fetched automatically via CMake FetchContent:
- FTXUI - terminal UI framework
- tiny-process-library - subprocess management
- sqlite_modern_cpp - modern C++ SQLite wrapper
- xlnt - xlsx reading
- lely-core - CANopen protocol stack
- fmt - text formatting
- nlohmann/json - JSON library
- clipp - CLI argument parsing
Available targets
make list # Show all targets
make build # Native build (dynamic linking)
make build_static # Native build (static linking)
make install # Install to PREFIX (default /usr/local), requires patchelf
make install_static # Install static binary to PREFIX
make docker-run ARGS='...' # Build and run in Docker (cross-platform)
make build_arm64 # Cross-compile for arm64 (dynamic)
make build_arm64_static # Cross-compile for arm64 (static)
make clean # Remove all build artifacts
Native build
make build
./build/native/canscope -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx
# or with CSV (faster parsing)
./build/native/canscope -e "candump can0" -j1939-csv thirdparty/j1939da_2018.csv
Docker (cross-platform)
Works on Linux, macOS (?), and Windows (?). Requires only Docker and Make.
# TUI mode - local CAN interface
make docker-run ARGS='-e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx'
# TUI mode - remote CAN interface via SSH (no data if will ask password - use public key access or sshpass utility)
make docker-run ARGS='-e "ssh user@remote candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx'
# Headless mode - create report about collected PGNs and SPNs
make docker-run ARGS='-hl -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx -of output.json'
Cross-compile for arm64
make build_arm64 # dynamic linking
make build_arm64_static # static linking
Requires Docker. SSH keys from ~/.ssh and /etc/hosts are forwarded into the build container for fetching private git dependencies.
Usage
# TUI mode (default)
canscope -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx
# Headless - JSON to stdout
canscope -hl -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx
# Headless - JSON to file
canscope -hl -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx -of output.json
# Read from stdin (pipe)
candump can0 | canscope -j1939-xlsx thirdparty/j1939da_2018.xlsx
# Record to SQLite database
canscope -rec -db recording.db -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx
# Record + TUI
canscope -rec -db recording.db -tui -e "candump can0" -j1939-xlsx thirdparty/j1939da_2018.xlsx
Note: J1939 decoding has only been tested with the Digital Annex 2018 edition. Other editions may work but are not guaranteed.
CLI flags
| Flag | Long form | Description |
|---|---|---|
-j1939-xlsx |
J1939 Digital Annex xlsx file | |
-j1939-csv |
J1939 Digital Annex csv file (faster parsing) | |
-e |
--execute-command |
Command to read CAN frames from (e.g. "candump can0") |
-hl |
--headless |
Headless mode (no TUI) |
-of |
--output-file |
Output file path (headless mode) |
-rec |
--record |
Record decoded values to SQLite |
-db |
--database |
SQLite database path (required with -rec) |
-tui |
Show TUI alongside recording | |
-h |
--help |
Show help |
Roadmap
- NMEA 2000 protocol support - NMEA 2000 decoding using canboat PGN database (JSON). Same 29-bit CAN ID as J1939, requires Fast Packet protocol implementation
- CANopen protocol support - CANopen decoding alongside J1939 (11-bit CAN ID, SDO/PDO/NMT)
- Other small features and enhancements - UI improvements, performance optimizations, additional export formats
