We recently bought a Herelink unit and connected it to our Cubepilot Orange. All seemed fine for a while until one day it simply stopped working. We figured it had gone dodgy, so we replaced the Cubepilot but the problem persisted so we replaced the Herelink unit too.
A voltmeter gives no continuity from the telemetry ground line to any other grounds. Putting an oscilloscope across the Herelink telemtry line shows that relative to the antenna and USB backshell grounds the telemetry line is pulling negative 3.3V, which is very surprising. Both Herelinks are doing it, so I wonder if it’s something common to their batch.
Pairing and SBUS seem to work fine.
Any ideas on how to fix it, or if we just have dodgy units?
It’s been a few months - I’m still no further to solving this. We ended up buying a -third- pair of Cubes and Herelink air units; same damn thing. I’ve been all over my design and there is nothing wrong with it - we’ve got spark arresting, grounding everywhere, anti-static protection, the works. After getting three Herelinks and three Cubes, I’m beginning to think that there’s either ghosts in my lab, or something else is going on?
Where is the electrical schematic drawing of your drone . this is essential to understand what you are doing with a nice rough and tested product such as the CUBE Orange !!