CAN Message Decoder

This project is a tool for decoding CAN (Controller Area Network) messages from a CSV file using a YAML configuration file. It reads the CAN data from a CSV file, decodes the specified messages based on the configuration file, and outputs the results to another CSV file. The tool supports both Intel (LSB) and Motorola (MSB) bit ordering.

Table of Contents

• Features
• Installation
• Configuration
• Usage
• Output Format
• License

Features

• Parsing CAN messages from CSV: Reads and decodes hexadecimal CAN messages based on a specified configuration.
• Customizable configuration: Easily configurable using a YAML file.
• Support for Intel and Motorola bit ordering: Decodes CAN messages using either LSB (Intel) or MSB (Motorola) format.
• Flexible output: Outputs the decoded values to a CSV file for further analysis.
• Local time adjustments: Calculates the timestamp of each message based on a specified local time.

Installation

1. Clone the repository:

git clone https://github.com/kochetovdv/canbus.git

2. Navigate to the project directory:

cd can-decoder

3. Install dependencies and build the project:

go mod tidy
go build -o can-decoder

Configuration

The configuration is defined in a config.yaml file, which specifies the input data file, local time, output file, and the messages to decode. Below is an example configuration file:

data_file: "data.csv"
localtime: "16:48:09.822"
output_file: "output.csv"
messages:
  - can_id: "107"
    start_bit: 24
    bit_length: 12
    dlc: 8
    message: "Engine RPM"
    method: "LSB"  # "LSB" for Intel, "MSB" for Motorola
    scale: 3.0
    offset: 0.0

Configuration Parameters

• data_file: The path to the CSV file containing CAN messages.
• localtime: The starting local time (used to calculate absolute timestamps).
• output_file: The path to the output CSV file where decoded messages will be saved.
• messages: A list of messages to decode:
  • can_id: The CAN ID of the message to decode.
  • start_bit: The starting bit position of the signal within the message.
  • bit_length: The length of the signal in bits.
  • dlc: Data length code of the message.
  • message: A description of the signal (e.g., "Engine RPM").
  • method: The bit ordering method. Use "LSB" for Intel and "MSB" for Motorola.
  • scale: Scale factor to apply to the decoded value.
  • offset: Offset value to add to the decoded value.

Usage

To run the program, use the following command:

./can-decoder -config config.yaml

Command-Line Options

• -config: The path to the configuration YAML file (default is config.yaml).

Output Format

The decoded messages are saved to the specified output CSV file (output.csv by default) with the following columns:

Time	ID	DLC	StartBit	Length	HEX	BIN	BIN_Converted	DEC	Value	Message
Timestamp of the message	CAN ID	Data Length Code	Start bit of the signal	Length of the signal in bits	Original HEX value	Binary representation	Extracted binary bits	Decimal value	Final calculated value	Message description

Example Output

2023-09-15T16:48:09.822+00:00;107;8;24;12;0x12AB;0001001010101011;001010101011;2731;8193.000000;Engine RPM

License

This project is licensed under the MIT License. See the LICENSE file for more details.