Hi Paul,Thank you very much for your explanation.
I just change the SR_3 parameters to the same as yours, but unfortunately the QGC still have message of unable to retrieve full parameters.
My flight controller is F405 wing, my UART Order is that:
SERIAL0 = console = USB, baud rate 115200
SERIAL1 = GPS= USART1
SERIAL2 = empty, USART2 used for PPM Input ( PPM PIN connect to sbus pin in FC)
SERIAL3 = ULRS（TX,RX,G,+5v）= USART3 baud rate 19200
SERIAL4 = empty = UART4 baud rate 19200
SERIAL5 = empty= UART5
SERIAL6 = empty= USART6
first I set the baud rate of serial 3 to 19200, but can’t connect to MP,
then I check the Manual of ULRS, There’s note that serial0= UART1, serial1= UART2 etc, so I change baud rate of serial 4 to 19200, it can be connect to mp right now.
I have always been confused about this, for some FC may be like this, but my circuit board serial port has been defined from 0.
and there’s only SRn_parameters from SR0to SR3,I try to change the SR4_parameters as yours, but it doesn’t exist.
Do you have any other advice about this issue,Thank you very much.