Allowed baud rates for Pixhawk UART for serial connections to support the F9P moving base mode

[rrr6399]

I’m cross-posting my question on the Pixhawk forum here since there are more eyes and it applies to the new RTK moving base capability:

Allowed baud rates for Pixhawk UART for serial connections

I noticed that u-blox is recommending setting the baud rate of the GPS connections to 460,800 to allow the moving baseline solution to work. In my case, my base RTK is on the ground/sea vehicle not on the copter so I’d like to set the baud rate to 460,800 for the telemetry connection as well. (Assume that the radio or communication path allows 460,800). 460 is not currently on the list of allowed baud rates for the serial connections outside the USB connection. Does anybody know if I can just ad…

[vbnhu]

According to my understanding 460,800 is used when both GPS1 and GPS2 are physically connected to your Pixhawk via UART while using RELPOSNED to calculate heading. Radios usually do not support more than 115,200. http://store.rfdesign.com.au/rfd-868-modem/ but there are a few of them out there with such high speed: http://store.rfdesign.com.au/rfd-868x-modem/

[rrr6399]

They are probably auto-configuring the serial port based on the GPS baud rate. You can’t directly specify 460,800 right now in a configuration parameter for the serial ports since it that speed isn’t in the mapping list, but I’m going to assume that it would work OK if I added that to the list in the firmware.

I have an RFD900X radio that supports this speed. I’m going to give it a try to see how it does. I may be able to reduce the baud rate since 460,800 may be required for accurate current heading information, but I’m hoping not for accurate position solutions.

Correction: It appears that you can specify an arbitrary baud rate directly by specifying the full number rather than the shorthand version. (i.e. 460800 rather than 460)