RC Radio connection

General Discussion
1

Hello, my name is Girish. I am part of a investigation group working on a project to develope aquatic drones. It is my first time working with drones and I was having some trouble with the connection of a RC radio. I am using a DX6e as my transmiter and an AR620 spektrum receiver. The receiver is connected to the navigator through a PPM encoder in the RC pins. After searching on the internet I changed the parameters

  • RC_PROTOCOLS = PPM
  • SERIAL1_PROTOCOL = RCIN
  • RC_OPTIONS = 36
    To calibrate the RC radio and other sensors I have been using mission planner, but even after these changes the program does not detect the radio. Reviewing the Navigator Hardware Setup guide I found that the RC input is configured for SBUS protocol by default and to use UART i would need to take out the jumper and solder it to the UART. Do I need to make this change? Are the parameters that I have used okay, do I need to change any other parameter? I have tried making the connection with a different reciever and transmiter that do support SBUS protocol and it has worked fine on mission planner just by changing the RC_ PROTOCOLS to SBUS, so I am guessing that the problem is the hardware setup or the parameters I have used.
2

Hi @girish -
The Navigator only supports SBUS, not PPM input. UART is a serial data protocol, not related to PPM. Sorry for the news!

I assume you’re working with a marine surface vessel, as radio waves don’t penetrate water for more than a cm or two?

3

Yes, water doesn´t penetrate. Thank you for your help.

4

Following my previous doubt, I have taken into account that the Navigator doesn´t support PPM protocol and have bought a SBUS encoder (JHEMCU SPP-SBUS PPM PWM signal conversion module Interchanger RC remote control receiver). But when I´am trying to calibrate the radio I´am getting an unsual error. The values of my transmitter are changing randomly on its own and I´am worried that this error can occur when I connect it to my boat. I´am getting this error both on mission planner and on QGC. Also I have tried this converter on a Navio controller with the same reciever and transmitter and dont get this error. Thinking maybe it is my Navigator parameters, I have tried using the same configuration mentioned in my previous doubt: RC_PROTOCOLS = SBUS, SERIAL1_PROTOCOL = RCIN and RC_OPTIONS = 36 but with a different converter (Receptor futaba R3008SB T-FHSS) and dont get this error. ¿Is there any additional parameter I should be changing? Any kind of help would be great.

5

Hi @girish -
Sorry for the hassle! I would guess that the receiver that is giving you issues has a noisy signal, or isn’t properly connected to the Ground plane of the Navigator? If it works normally with some hardware, the issue is likely the hardware you’re using and not any autopilot parameters…

6

The thing is I´ve tried using the same transmitter, receiver and encoder on a different flight controller, the Navio2 specificly, and don´t get this error.
A part from using the 3 pins that the navigator has for the RC connection, is there any additional configuration I need?