Omnibus nano v6.2 current and voltage readings

After configure the BATT_VOLT_PIN=12 and BATT_CURR_PIN=11 according the documentation, I observed the channels were mixed. The correct way is:
Could you update the documentation page in V6.x revision section, please?

@hwurzburg can you look at this?

The documentation is correct…
from the HWDEF:


if this is incorrect, it will take more that changing the documentation…the hwdef would have to be changed…we need additional confirmation that the hwdef is wrong…its also possible that the v6.2 (btw I can only fine 6.1 versions on the web) changed the wiring…
its also possible that there are variations in the 4in1esc connector pinout for different escs

Hello Henry,

From @iter comments in his post, I also faced the same problem on my side. I set up the correct order for the signals that come from the ESC side and it didn’t work for me either. The battery readings were also around 0.56V.

  • My first experiment was to disconnet the ESC connector from the FC and Supply the FC via the main pins (GND and VBAT IN) and also configure BATT_VOLT_PIN=12 BATT_CURR_PIN=11 as mentioned in Ardupilot documentation. (note: VBAT_IN pin and CURR pin were floating in the ESC connector side)
    Result: VBAT readings were OK and CURR values were ignored.

  • Then I tried to measured the VBAT level on the ESC connector side with a Multimeter to check if had the same VBAT value.
    Result: Same voltage between main supply VBAT IN and VBAT IN from ESC connector side. And also the measured resistance between them was 0R.

  • Then I tried to touch the CURR pin with with Multimeter’s probe, just to check if there was any non-conformity in the FC.
    Result: When I touch in the CURR pin with the probe, I observed VBAT values oscillating randomly in the Mission Planner.

  • So I decided to set BATT_VOLT_PIN=11
    Result: The oscillating behaviour in the voltage readings was gone.

  • I set BATT_CURR_PIN=12 and then I tried again to touch CURR pin with my finger and I observed: only the Current values were oscilating in Mission Planner. So, at this point I assumed that it was the correct ADC for the CURR pin.

  • Then, I removed the main power wires from the FC. And connect the FC to the ESC via the ESC cable.
    Result: it’s working fine and I’m able to read the battery voltage and the current consumption.

My thoughts: Probably the manufacturer mixed the ADC channels in V6.2.

@Andre_Quinta please show high res images of your actual board’s front and backside, most interest would be seeing individual silkscreen hw revision prints obviously. and please share a link to where you purchased the board. thanks in advance!

on a sidenote i do have one original v6 and two 6.x revisions (purchased from airbot) in use, all three run pins correctly on hwdef defaults. hw-revisions and corresponding documentation from the manufacturers’ side still is basically non-existent at this point though. even the airbot webshop still shows images / docs of the original v6.

cheers, basti.

Hi @vierfuffzig,

Sorry I cannot share the high res images of my board now because it already mounted in the model. But you can look for the same images here, the board I’m talking about is Omnibus F4 nano v6.2. I had ordered it from Bangood.
Many Thanks!

@Andre_Quinta as mentioned above the main point is figuring the exact ADC / pin layout of your individual board revision. your tests mentioned above show that the VBAT solderpad is working on PC12 as expected, matching hwdef and other board revisions.
if i get this right we now need to figure each 6.x revision’s exact pin layout of the ESC connector. from what i have read so far i suspect an erroneous ESC connector’s pin description in some board revisions.

Hello @vierfuffzig

VBAT on PC12 was working because PC12 was floating at that time. No current input was connected to CURR pin, that’s the reason! From the moment I touched in current pin, I read floating Battery values.
The Electric Schematic from my point of view is correct but the ADC channels refered in Ardupilot documentation are mixed for V6.2 PCB.
That configurations are working for me. May be a note for this version can be append to the ardupilot documentation.

based on the very limited manufacturer documentation available, the more recent board revisions do not differ from the original nanoV6 in terms of ADC pin layout and are supposed to run the same firmware. see iNav for correspondence on this (uses the fireworksv2 target).
all i can say is that on my boards, the VBat solderpad definitely connects to PC12, which matches ardupilot documentation, ardupilot hwdef and inav target expectation.
that’s why i suspect a mix-up in the manufacturer’s esc-connector description of a distinctive board revision. this connector pinout allegedly has changed between 6.1 and 6.2, but it does not seem to be the case in all 6.2 boards.
so imho it would be good to FIRST try and figure if we can tell which exact board type does have that issue and THEN add that to the ardupilot documentation. i can’t tell that based on the information i have right now.