Libcanard is a compact implementation of the UAVCAN/CAN protocol stack in C99/C11 for high-integrity real-time embedded systems.
UAVCAN is an open lightweight data bus standard designed for reliable intravehicular communication in aerospace and robotic applications via CANb bus, Ethernet, and other robust transports.
This repo provides the bare minimum example of Libcanard 2.0 usage with STM32F series MCU, both messages transmition and receiving. It does not use the advised memory allocator O1heap for the sake of simplicity. Communication with the CAN bus is done via standard STM32HAL driver. The example is tested on STM32F446RExx MCU, but should be portable on any chip of STM32F family.
The bxCAN is configured for 1 Mb/s speed. Example application generates a heartbeat message with 1s period and pushes it to the CAN bus in polling mode. Also application subscribes for the Real64-array message and processes it in interrupt triggered by each new CAN frame.
Open .ioc file in the STM32CubeMX and generate source files for your preffered IDE. Then just add canard.c path into the sources and /include into the search directories.
To communicate with node you have to start CAN interface first. Open terminal window and type:
sudo ip link set can0 up txqueuelen 65535 type can bitrate 1000000To view heartbeat messages from the MCU you need tool called Yakut. In new window type:
export UAVCAN__CAN__IFACE=socketcan:can0
yakut sub uavcan.node.Heartbeat.1.0To send Real64-array to the node use the following:
yakut -i 'CAN(can.media.socketcan.SocketCANMedia("can0",8),59)' pub 1620.uavcan.primitive.array.Real64.1.0 'value: [1.1,2.2,3.3,4.4,5.5]'