RFD900ux extremely slow connection or doesn't connect with MP, works with QGC

ArduCopter Copter 4.5
1

This is my first time using the RFD900ux. I’ve used the RFD900 many times in the past.

This build is using a Pixhawk 6x, and the RFD is connected to serial 2, and set to mavlink2. I’ve also tried mavlink1, same result.

Problem - Takes many attempts to connect in MP, and when it does, params are extremely slow to download.

This does not seem to be an issue with QGC. I tested the radio with another FC I had, the Pixhawk 5x with stock params, and it worked flawlessly.

Here are the params I’m currently using. I’m on the latest stable firmware, and I’ve tried both the beta MP and stable MP.
m1200.param (18.9 KB)

2

I have the same problem. I am trying to connect RFD900ux telemetry and pixhawk PX4 via qground. Did you find a solution to this problem?

-I checked all the cable connections. Red and green lights are flashing on the chips.

3

Hi Vosair,
Long time - no chat :slight_smile:

What range are you expecting? I ask because if you’re trying for 150km then keep the baud rate at default, but if range will be within line of sight or maybe some more (up to the documented 45km) then we can easily go to a higher more usable baud rate.

Start by disabling RTS/CTS in the Ardupilot params and in the radios, set the other baud rate and details I’ve specified and let’s see what we get.

BRD_SER2_RTSCTS,2 <- set this to specifically enabled to disable to match the radio and wiring
SERIAL2_BAUD,115
SERIAL2_OPTIONS,0
SERIAL2_PROTOCOL,2

On the RFD radios also set these:

Baud       115
Air Speed  200
ECC        off
RTS/CTS    (can be off, also set BRD_SER2_RTSCTS to  match)
Op Resend  off
Max Window 80

RTS/CTS can be used if the wiring is in place, or even disabled when the wiring is in place.

If changing parameters via any telemetry link I would advise re-reading all the parameters to verify that your expected changes actually took place.

4

You just need to select the correct comm port on your computer, and a baud rate that matches what the radios are doing.
Use my settings I listed for a higher baud rate.