Servers by jDrones

Multi antenna integration

(Andrés Ábrego) #1

Sorry for the title
We are building a big rover (1200mm long, over 70kg) and we want to put the antennas in/on a pole, both gps antennas on top, separated around 25cm, and telemetry (433) and RC (2.4) antennas inside the pole.
I would love to have some feedback from the community, we want to stick to the “one pole solution” and the body of the rover is fully metallic.

(gmorph) #2

Sounds good. The only concern is if the 433 will cause interference with the GPS cables going past it in the pole. If you could someone mount the 433 antenna away from those cables that would be ideal.

The top plate should be a nice big metal ground plane for your GPS antennas.

Thanks, Grant.

(Andrés Ábrego) #3

It will be an aluminium plate, thanks for the advise.
Also we will try to find a solution for the telemetry, I assume that your tip was about avoiding harmonics with gps isn’t it?
Also, which high end telemetry kits are available nowadays for pixhawk 2? We want about 1km range, I am used to that range with cheap telemetry kits in planes, but have never done anything on rovers…

(WickedShell) #4

I’d also note that depending upon that cable length you are at a much higher chance of getting I2C interference with the external compasses. This is of course testable, and is much less of a problem with the digital oversampling on the bus, but it does become a concern with long I2C cables especially in close proximity to a telemetry radio.

(gmorph) #5

Not harmonics - just EMF interference. As WickedShell says with such a long I2C cables any interference cause cause data corruption.

I don’t have a recommendation for 433MHz radios. Not a frequency band I use. Sorry.

Thanks, Grant.

(hans bert) #6

tip for the cable problem, use a cat6 or better cat7 ethernet cable and ground the shield and all unused wires propperly. Works great for me even for longer i2c distances.

(Andrés Ábrego) #7

I was thinking the same, but I wonder if it could be worse to ground all of them together, won’t it make easier to transfer “noise”?

(Nicolas Chaslot) #8

This looks really good!
Do you have any pictures of the rover? :slight_smile:
Concerning the telemetry, i use DragonLink on my rovers so i have both control and telemetry over the same link and it works well… But still need to separate it from GPSs