A simple proxy between ROS and mavlink without any wrapper. That means the proxy will convert anything it received. And the most important thing is that the code is easy to read and modify.
Meanwhile it has two extra master-slave communication nodes which can be used in a scenario that only a half-duplex broadcasting network is equiped.
Some parts of the code are modified from https://github.com/mavlink/c_uart_interface_example
Limitations: this proxy can only convert about 5 often-used topics now, Because increasing the number of topics is a simple physical task.
Ignore my Chinglish.