Pixhawk 6X without IO

I’m designing a carrier board for Pixhawk6X, and hope to avoid having to implement the IO part. DS-010 and DS-012 are not really clear on what is the “standard” method of connecting S.Bus (and analog RSSI) to the FMU? Is such configuration possible at all, or is the IO mandatory, if we want to receive S.Bus control? Can pin 70 of X1 (USART6_RX_FROM_IO__RC_INPUT) be used for this?


I was looking to do the same. I ultimately decided to invest in the CubePilot modules since their carrier boards actually make sense (no FMU), they have great support, and even reference designs. And currently it’s only one center mounted 80pin connector, not two.

I would definitely use the 6X. In testing I’ve done, it’s a great board.

As for the question, @Vincentpoont2 can prob answer that. Stick with the 6x.

You will not be disappointed.

Vince from HolyBro plans on releasing some schematics shortly.


I am trying to design custom carrier board for Pixhawk 5X FC. I’m thinking of two methods:

Method #1:

Custom carrier board will NOT consists of IO processor (STM32F103C8T6).
In this case, I have a doubt. “How to send RC_IN signal directly to Pixhawk cube ?”
Upon analyzing the schematics of carrier board, i understood that RC_IN signal & inverted RC_IN signal is going into IO processor (pin_29) & (pin_22) respectively.
& from PIN_12 of IO processor an output signal “USART6_RX_FROM_IO__RC_INPUT” is coming & going into PIN_70 of 100-pin_X1_connector present under the cube.
I would like to know, Is there any way how to send RC_IN signal directly to Pixhawk cube by by-passing the IO_processor
I tried to short (inverted RC_IN signal) to (PIN_70 of 100-pin_X1_connector). But it is not working. May be because RC_IN is S.BUS signal & IO_processor is accepting in UART protocol
If this method is not possible, then i thought of method #2

Method #2:

Carrier board will consists of IO processor (STM32F103C8T6).
If this is the case, where could i get the firmware to flash the IO processor ?

I request you to look into this and suggest some solution or any other method that you’ve followed.

Thanking you