Power module voltage reading fluctuate over telemetry

The voltage reading fluctuates over telemetry connection while it is stable when connected via USB cable is this issue common? How to fix it?

It is normal, especially if it is being measured when the UAV is flying.

But its on the bench plus its fluctuating like 15.39V -16.4V i am using a 4s lipo when connected via wire its very stable.

Post a link to .bin log file

i have cleared all the log file while i was trying to re flash it but here is a video link when i connected this via telemetry you see the voltage fluctuating


This is normally indicative of a bad setup on the aircraft. Usually doing something like powering a high power telemetry radio (such as a RFD900) off the autopilot’s 5V line will cause this. It’s causing power ripples in the system and ground lift, which is throwing off the ADC readings of the battery. Even if your radio is lower power it may be introducing to much load on the regulator used for powering the autopilot, it depends a lot on the hardware in question.

nothing using RFD900. I am using 500mw telemetry i will try to power it separately let see if solve the issue

The normal warning (and the one you’d see in the wiki for RFD900) is anything above ~100 mW tends to be problematic.


so i have connected the power wire to separate source dose this looks fine now ?

Nah, still doesn’t look good. When you say a separate source do you mean a dedicated BEC or similiar, or just a different port of the flight controller?

The other sorta obvious error that you could do, but I’m assuming you haven’t is wrapping the power monitoring wires in close proximity to the antenna.

it working fine now after connecting it to dedicated source
thank for help @WickedShell