about baudrate of serial

[roseyangyu]

I want to control the telem 1 to stop sending mavlink message,I want telem 1 to output the message that is Custom-Defined.And how do I do to config the baudrate of serial4/5?

[julianoes]

May I ask what piece of hardware you are referring to? That way we can figure out what your requests map to in code.

[roseyangyu]

I used pixhawk 2,I want to config telem1 and serial4/5.I hope the telem1 don't output mavlink so much so that I can make it output the message that is I need.And the baudrate of serial4/5 how to config?

[roseyangyu]

In QGC ,I can't fiind the parameter to config that

[julianoes]

Ok, Pixhawk2, let's check the docs:
https://docs.px4.io/en/flight_controller/pixhawk-2.html

It tells us that this is a FMUv3. Therefore, let's check the init script which is run:
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/ROMFS/px4fmu_common/init.d/rcS#L18-L25

Then everything mavlink will be started in rc.mavlink according to:
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/ROMFS/px4fmu_common/init.d/rcS#L486-L489

So, let's look at rc.mavlink. I believe the default Telem1 mavlink instance is this:
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/ROMFS/px4fmu_common/init.d/rc.mavlink#L38
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/ROMFS/px4fmu_common/init.d/rc.mavlink#L78

I want telem 1 to output the message that is Custom-Defined.

For this you can comment out the line above, so mavlink is not started on telem1. Then you can write your own module which writes your custom defined thing.

And how do I do to config the baudrate of serial4/5?

Let's go back to this:
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/ROMFS/px4fmu_common/init.d/rcS#L24-L25

Therefore Serial 4/5 should be UART7/UART8. The baudrate is defined in the defconfig:
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/platforms/nuttx/nuttx-configs/px4fmu-v2/nsh/defconfig#L1100
https://github.com/PX4/Firmware/blob/90b60d44dc4fa4d859051ef2f46c8d6f03054279/platforms/nuttx/nuttx-configs/px4fmu-v2/nsh/defconfig#L1113

[bkueng]

FYI this will make the UARTs configurable: #10337

[roseyangyu]

I‘m exciting very much! Thank you very much! @julianoes and @bkueng

[roseyangyu]

but I have not rc.mavlink. I use v1.8.0.

[julianoes]

but I have not rc.mavlink. I use v1.8.0.

Same thing there:
https://github.com/PX4/Firmware/blob/v1.8.0/ROMFS/px4fmu_common/init.d/rcS#L604

[roseyangyu]

I have config UART7 and UART8 to 115200,but It seems that the baud rate has not changed.It still is 57600.

[roseyangyu]

config telem1 sucessfully! thank you again

[julianoes]

@roseyangyu have you done a make clean after changing the defconfig?

[roseyangyu]

oh i'm sorry.thank you very much