mavlink_parse_char() always returns zero with Cube-Orange

[Johanné Jansen van vuuren]

I recently got a Pixhawk Cube-Orange with Here2 GPS and I loaded the apj firmware for Arducopter using Mission Planner (version 1.3.70) and it connects just fine.

Now I've connected the cube to a Raspberry Pi 3B+ and I wanted to test the mavlink interface using this example:

https://github.com/mavlink/c_uart_interface_example.git

I've cloned that repository onto the Pi which is running Ubuntu Core 18.04 and when I run the script it detects System and Component ID 

but then doesn't detect the Cube's initial position. I've done some debugging and can see that this function:

mavlink_parse_char(MAVLINK_COMM_1, cp, &message, &status);       //Line 133, serial_port.cpp

always returns zero and so the program just stays in a loop waiting for messages to be parsed. The screenshot shows the output of the program

and it just stays like that until I press Ctrl-c to exit.

I'm not sure how to proceed from here or why that function returns zero, would anyone be able to offer some advice?

Thanks!

Johanné

[Hamish Willee]

Hi Johanné,

A guess. It is waiting on SPECIFIC messages in https://github.com/mavlink/c_uart_interface_example/blob/master/mavlink_control.cpp#L241. These may not be emitted by ArduPilot.

You can check what messages you get using mission planner and then update the code to look for those.

Cheers

Hamish