I’m new to ArduPilot so please bear with me. I’ve got a Radiomaster RP1 ELRS receiver which I now want to connect to my Pixhawk 6C. I know CRSF is a different protocol from ELRS, but in the short user manual which came with the RPI receiver it says
Wireless Protocol: ELRS 2.0 pre-installed
Bus interface: CRSF
So if I understand this correct, ELRS is what goes over the air, and CRSF is what the RP1 talks to the flight controller. Right?
To allow CRSF and embedded telemetry available in Fport, CRSF, and SRXL2 receivers, a full UART, such as SERIAL5 (UART3) would need to be used for receiver connections. Below are setups using Serial6. For the 6C Mini, SERIAL1 - SERIAL4 would need to be used.
I’m trying to wrap my head around this. So I need a “full UART” such as “SERIAL5 (UART3)” or later they also mention “Serial6”. In the Holybro docs I read that TELEM2 is UART5 and TELEM3 is USART2. I see no mention of SERIAL5, UART3 or Serial6 though. I know UART is a serial connection and as far as I understand USART2 is a more advanced version of UART5.
So since TELEM1 is used for the telemetry radio, am I correct in my assumption that I can connect the Radiomaster RP1 ELRS receiver to either the TELEM2 or the TELEM3 port on the Pixhawk 6c? Is either of them a better choice? Any tips are welcome!
For historical reasons the UART number often doesn’t match the serial port number on these ports. The serial port is what you configure. The UART number only matters if the manufacturer uses it for labeling ports. The 6C has 6 serial ports number 1-6 and any of them can be used with CRSF/ELRS since this is an H7. ELRS is an open source clone implementation of the closed source CRSF protocol from TBS. It refers to both the over-the-air protocol and the protocol used between the radio RX and the flight controller.
I also have a problem with connection my radiomaster ER5a to pixhawk 6c
I even don’t understand which socket I have to use. plz help me)))
Binding is ok, but if I connect this receiver to ppm/sbus Rc socket nothing happened.
If you’re using an ER5A by default it will only output PWM signals, as it’s meant for controlling a RC Plane - so that won’t work with the Pixhawk. You can change what that receiver outputs to CRSF, but it involves configuring it differently from the receiver’s Wifi page as well as running master firmware currently. Or you can buy a different ELRS receiver that just outputs CRSF natively (these are much more common than the PWM type you have). Radiomaster RP1,2, or 3, Jumper, Betafpv all make models like this. Then you would wire that CRSF output into a serial port on the Pixhawk, TX to RX, RX to TX, 5V to 5V, GND to GND, etc.
I unfortunately don’t have an answer to your question @svinozhop , but since I started this thread I do want to say that I did manage to connect my ELRS receiver to the pixhawk 6c I have. In the end I also had a problem with binding, for which I opened another thread here. Finally I concluded in the other thread all the steps that I took to bind and connect the elrs receiver to pixhawk and ardupilot.
Thanks for all your help here as well, and good luck to @svinozhop