Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/TheMatjaz/VCAN

VCAN is a tiny virtual CAN and CAN-FD bus library in C
https://github.com/TheMatjaz/VCAN

bus c c11 can-bus can-fd library virtual virtual-bus virtual-can-bus

Last synced: 27 days ago
JSON representation

VCAN is a tiny virtual CAN and CAN-FD bus library in C

Awesome Lists containing this project

README 

        
VCAN is a tiny virtual CAN and CAN-FD bus in C

===============================================================================



Especially useful for debugging and testing without using actual

CAN-connected devices, VCAN is a tiny C library that allows the user to connect

virtual nodes on a virtual bus and make them react whenever someone transmits a

message on the bus.



After the transmission, each node obtains a copy of the message

and a callback on each node is called to warn the node of a message being

received.



Known limitations

----------------------------------------



VCAN is simple, synchronous and single-threaded. It does not simulate

transmission errors, collisions, arbitration, etc. just pure data transfer.

Callbacks should be fast.



... but you are free to alter it to your specific needs!



Usage example

----------------------------------------



```c

// Create and initialise a virtual bus.

vcan_bus_t bus;

vcan_err_t err;

err = vcan_init(&bus);  // Fails on NULL args

assert(err == VCAN_OK);



// Create 3 virtual nodes.

// Make them print the received message on reception using the callback.

// The definition of callback_print_msg() is available in the tst/test.c file

vcan_node_t node1 = {

        .id = 1,

        .callback_on_rx = callback_print_msg,

};

vcan_node_t node2 = {

        .id = 2,

        .callback_on_rx = callback_print_msg,

};

vcan_node_t node3 = {

        .id = 3,

        .callback_on_rx = callback_print_msg,

};



// Connect the nodes to the bus - by default up to 16 nodes.

// It's just a #define constant, it can be changed easily.

err = vcan_connect(&bus, &node1); // Fails on NULL args or full bus

assert(err == VCAN_OK);

err = vcan_connect(&bus, &node2); // Fails on NULL args or full bus

assert(err == VCAN_OK);

err = vcan_connect(&bus, &node3); // Fails on NULL args or full bus

assert(err == VCAN_OK);



// Transmit!

puts("Transmitting from node 1, node 2 and 3 receive.");

const vcan_msg_t msg = {

        .id = 0xABCD,

        .len = 3,

        .data = {0x00, 0x1A, 0x2B}

};

err = vcan_tx(&bus, &msg, &node1); // Fails on NULL bus or NULL msg

assert(err == VCAN_OK);



// Because we transmitted from node 1, only node 2 and node 3 received the

// message. Of course node 1 did not receive it, because it sent it.

// The callbacks were triggered immediately and your stdout should

// look like this:

//

// Transmitting from node 1, node 2 and 3 receive.

// Node 2 received ID: 0x0000ABCD | Len: 3 | Data: 00 1A 2B

// Node 3 received ID: 0x0000ABCD | Len: 3 | Data: 00 1A 2B



// If you transmit from a NULL node, then all nodes receive the message.

puts("Transmitting from NULL node, everyone receives.");

err = vcan_tx(&bus, &msg, NULL);

assert(err == VCAN_OK);



// And now the stdout should look like this:

//

// Transmitting from NULL node, everyone receives.

// Node 1 received ID: 0x0000ABCD | Len: 3 | Data: 00 1A 2B

// Node 2 received ID: 0x0000ABCD | Len: 3 | Data: 00 1A 2B

// Node 3 received ID: 0x0000ABCD | Len: 3 | Data: 00 1A 2B



// Disconnecting nodes is easy.

err = vcan_disconnect(&bus, &node2); // Fails on NULL args or already

// disconnected node

assert(err == VCAN_OK);



// Now node2 will not receive anything anymore.

puts("Transmitting from node 1 after node 2 disconnection,"

     " node 3 receives.");

err = vcan_tx(&bus, &msg, &node1);

assert(err == VCAN_OK);



// And now the stdout should look like this:

//

// Transmitting from node 1 after node 2 disconnection, node 3 receives.

// Node 3 received ID: 0x0000ABCD | Len: 3 | Data: 00 1A 2B

```



You can also check the `tst/test.c` file for more examples.



Include it in your project

----------------------------------------



### Static source inclusion



Copy the `inc/vcan.h` and `src/vcan.c` files into your existing

C project, add them to the source folders and compile. Done.



### Compiling into all possible targets



```

mkdir build && cd build

cmake .. -DCMAKE_BUILD_TYPE=Release

cmake --build .

```



This will build all targets:



- a `libvcan.a` static library

- a test runner executable `testvcan`

- the Doxygen documentation (if Doxygen is installed)



To compile with the optimisation for size, use the

`-DCMAKE_BUILD_TYPE=MinSizeRel` flag instead.