Splicing ezUHF wire into ezOSD for RSSI. Question.

[BayAreaCrasher]

So I'm looking to splice the cable from the ezUHF receiver to the ezOSD bus cable. should I connect all four cables as per the instructions in the attached image or is it just hte signal wires and power? I'm afraid of a ground loop.

[jacq]

Only 3 wires... indeed not the ground (black)

[Freshmint]

where is that pictures from?

[BayAreaCrasher]

from the ezUHF manual

[Freshmint]

the manual doesn't say not to connect the ground (black) wire?

[BayAreaCrasher]

nope, manual as far as I can tell says to splice all of them:

"On the EzOSD end, the wires should be connected as follows:
Note: These can be simply spliced into the cable which connects the EzOSD to the current sensor.

Red: +5v
Black: Gnd
Yellow: i2c SCL
White: i2c SDA

Note that when using the direct link between the EzOSD and the EzUHF, the RSSI calibration in the EzOSD is not required. This calibration feature applies only to the connection of an analog RSSI signal to the EzOSD."

[Freshmint]

is ground loop bad?

[ssassen]

Do not splice in the GND, ground loop = bad, it'll create an interdimensional gravitational vortex that will eat up your FPV airplane, and a RTH will not, repeat, will not, bring it back.

[FinalFrag]

You might want to update the manual for that Sander, it cleary states to do all 4...

[Scotttu]

It did say to do all 4 and I did so. Should I be snipping the grnd wire or is it OK?

My ground is via BEC powering the ezUHF and ezOSD - all my equipment parallels out from the ezOSD Current sensor prior to the ESC - nothing coming from ESC so I don't think I have a ground loop (?).

I was trying to adjust the min/max RSSI and it won't let me do it in the ezOSD config (Using buttons on EzOSD).
But I get RSSI when I power everything up.

[FinalFrag]

From the manual: you don't need to do the calibration when using the cable. It's one of the advantages of using all immersionrc products.

I would cut the gnd wire and see if it changes anything... if not, leave it disconnected :)

[jimmaplesong]

My zephyr is seven gluesticks heavier after I didn't cut the ground. Five minutes into a flight, the rssi all went to 255, and It did a 800' dive in failsafe.

Cut the ground.

[FinalFrag]

Ouch, sorry to hear that...

Guess I won't be connecting my GND when I make the cable :D

[chicken sashimi]

http://i242.photobucket.com/albums/ff183/cptlzr/2.gif

Ok.. this is madness!
The manual says connect the ground, people here say cut the ground and stores like getfpv.com (http://www.getfpv.com/ezosd-to-ezuhf.html) and TBS (http://team-blacksheep.com/products/prod:ezbus)are selling prefab cables that have the ground connected.

What's the best approach?

[ssassen]

I always suggest to remove it as on most builds it creates an additional groundloop.

[chicken sashimi]

ok, willdo. thx!

[m.cheraghi]

Should I only cut the ground to the UHFrx on the link cable? Or also cut the ground to the OSD on the link cable?
The in and out of the OSD is only a pass through right? Not powering the OSD? so I guess the ground should still be there on the ezLink to the OSD?

I will power my UHFrx from ESC BEC

[chicken sashimi]

I think it depends on your configuration. A wiring diagram would help to make that call.. basically you're just trying to eliminate a ground loop.
All I had to do was cut the ground on the rssi link cable (ezUHF to current sensor).