# dbcc

dbcc can translate data base CAN files into Rust code. The generated code allows interacting with CAN signals in a type safe manner by e.g. matching against signal value enum types. Furthermore it provides a convenient way to use SocketCAN BCM Sockets, via tokio streams, to filter for a specified message by can identifier.

Features

• [x] Generate message, signal decoder code
• [x] Generate message id constants
• [x] Generate enums for matching against signal values
• [x] Generate tokio streams for CAN messages
• [ ] Generate message, signal encoders

Option 1 - Run CLI

Install cargo install dbcc

Generate code using the CLI. dbcc --input dbcc j1939.dbc > j1939.rs

For warnings during the generation run with:

RUST_LOG=info dbcc j1939.dbc > j1939.rs

Option 2 - build.rs

Generate code at build time. Add the following to your build.rs. Adapt the dbc input path and target path according to your needs.

```Rust use dbcc::{DbccOpt, cancodegen}; use can_dbc;

use std::fs::File; use std::io::prelude::*; use std::path::Path;

fn main() -> std::io::Result<()> { let dbcs = &[ ("./dbcs/j1939.dbc", "./src/lib.rs"), ]; generatecodefor_dbc(dbcs)?; Ok(()) }

fn generatecodefordbc>(inputoutput: &[(P, P)]) -> std::io::Result<()> {

for (input_path, output_path) in input_output {
    let mut f = File::open(input_path).expect("Failed to open input file");
    let mut buffer = Vec::new();
    f.read_to_end(&mut buffer).expect("Failed to read file");

    let opt = DbccOpt {
        with_tokio: true,
    };

    let dbc_content = can_dbc::DBC::from_slice(&buffer).expect("Failed to read DBC file");
    let code = can_code_gen(&opt, &dbc_content).expect("Failed to generate rust code");

    let mut f = File::create(output_path)?;
    f.write_all(&code.to_string().into_bytes())?;
}

Ok(())

} ```

Include

• Move the generated rust file to your project's src/ folder.
• Add the following dependency to your project's Cargo.toml YAML [dependencies] byteorder = "1.2"

Use

``Rust /// If you are using Rust 2018 noexternal crate byteorder;` is necessary /// Generated module mod j1939;

fn main() { // J1939 - Operators External Light Controls Message Id let canmessageid = 2365443326u32; // can frame data field (0-8 bytes) let canframedata: Vec = vec![0x00, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00];

// CAN Message ID constant from generated code
if can_message_id == j1939::MESSAGE_ID_OEL {
    // J1939 - Operators External Light Controls Message
    let oel = j1939::Oel::new(can_frame_data);

    // Signal indicate the selected position of the operator's hazard light switch.
    match oel.hazardlightswitch() {
        j1939::HazardLightSwitch2365443326::HazardLampsToBeFlashing => println!("Hazard Lamps To Be Flashing"),
        j1939::HazardLightSwitch2365443326::HazardLampsToBeOff => println!("Hazard Lamps To Be Off"),
        j1939::HazardLightSwitch2365443326::NotAvailable => println!("Not available"),
        j1939::HazardLightSwitch2365443326::Error => println!("Error"),
        j1939::HazardLightSwitch2365443326::XValue(_) => unreachable!(),
    }
}

} ```

Including SocketCAN Streams

• Make sure you pass the --with-tokio flag when invoking dbcc.
• Move the generated rust file to your project's src/ folder.
• Add the following dependencies to your project's Cargo.toml YAML [dependencies] byteorder = "1.3" futures = "0.1" tokio = "0.1" tokio-socketcan-bcm = "0.3"

```Rust mod j1939;

use futures::future::Future; use futures::stream::Stream; use std::io; use std::time::Duration; use tokio;

fn main() -> io::Result<()> { let ival = Duration::from_secs(0);

let f = j1939::Oel::stream("vcan0", &ival, &ival)?
    .for_each(|oel| {
        // Signal indicates the selected position of the operator's hazard light switch.
        match oel.hazardlightswitch() {
            j1939::HazardLightSwitch2365443326::HazardLampsToBeFlashing => {
                println!("Hazard Lamps To Be Flashing")
            }
            j1939::HazardLightSwitch2365443326::HazardLampsToBeOff => {
                println!("Hazard Lamps To Be Off")
            }
            j1939::HazardLightSwitch2365443326::NotAvailable => println!("Not available"),
            j1939::HazardLightSwitch2365443326::Error => println!("Error"),
            j1939::HazardLightSwitch2365443326::XValue(_) => unreachable!(),
        }
        Ok(())
    });

tokio::run(f.map_err(|_| ()));

Ok(())

} ```

Naming

Recommendation: Value descriptions aka VAL_ ... should contain only alphanumeric characters or underscores and should start with an alphabetic character. E.g. VAL_ 100 "111 Wunderschön Inc" 255 should be VAL_ 100 " Wunderschoen Inc 111" 255

• Enums: Generated names are prefixed with an X if the name does not start with an alphabetic character.
• Enums: Characters that are not alphanumeric or _ are replaced with an X
• Enums: An XValue(f64) variant is added to each enum since value descriptions often do not cover all possibilities.