I followed this link https://github.com/mavlink/c_uart_interface_exampleand tested,but it only prompted
"OPEN PORT
Connected to /dev/ttyACM0 with 57600 baud, 8 data bits, no parity, 1 stop bit (8N1)
START READ THREAD
CHECK FOR MESSAGES
Found
GOT VEHICLE SYSTEM ID: 1
GOT AUTOPILOT COMPONENT ID: 1
"
but it did not show any position information implemented by “autopilot_interface.cpp”
I need someone explain for this.