I am very confused about voltage and current scale in INAV.


Board: Mamba F405 MK2 (HW Rev. 3)
ESC: Mamba F40 MK2
Target: FURYF4OSD
INAV Version: 2.6.1

According to diatone website "Voltage Scale" is 110 and "Current Scale" is 115.

Voltage scale:

If I set it to 110 the voltage in INAV shows 2,41 V instead of 24,14 V measured with voltmeter. This is why i set voltage scale to 1100 which gives me correct values. I am fine with this.

Current Scale:

I tried calibration with "general method" (read charged mAh) described in INAV wiki for >6 times now and i failed to get plausible values. This lead me to start from scratch again: If I measure current draw in idle state I get ~ 170 mA out of my current meter. With Current Scale set to 115 (exact 113) I got current draw of 170 A in INAV. In theory I need to set the current scale to 115000 (exact 113000). But it is not possible to set values above 10000 (Need 113000) for current scale in INAV.


Is this a bug? How to set correct scale?

1100 doesn't sound correct. You you sure INAV is not reporting average single cell voltage and not total voltage?

I made screenshot with 110 Voltage Scale and 1100 Voltage Scale. Seems right to me, its not reporting single cell voltage ... .

iNav current/voltage scales are a factor of 10 higher than BF. 1100 sounds correct.

Try 1150 for the current scale. Fully charge a pack, fly, then recharge the pack and compare the amount recharged with the mAh used from iNav.

I did the current calibration method with ~10 packs. Now I am @ 1876 current scale. The strange thing is: When i measure current flow with battery & disarmed my circuit analyzer showed 170 mAh, while INAV showed 9 A (screenshots attached) ... . This means while disarmed "capacity drawn" is running very very fast ... . Something is horribly wrong and i cant figure out what.

Does the current draw in flight look reasonable? You might need to adjust the offset. See here:


Have you verified the current sensor is connected to the ADC? You could alternately try setting the current sensor type to "ESC" if the ESC telemetry is connected properly.

(09-Apr-2021, 07:47 PM)V-22 Wrote: Does the current draw in flight look reasonable? 
Have you verified the current sensor is connected to the ADC?
You could alternately try setting the current sensor type to "ESC" if the ESC telemetry is connected properly.

Looks like you are pointing into the right direction, thanks!

I reviewed the DVR of my last flight, it turned out that the current is around 7 A during the complete flight ... . I didnt notice till today ... . So i tried to calibrate to a "random" value ... .  

Sensor type "ESC" is not working at all (Reporting 0 A). Which is according to diatone.us website correct (No ESC telemetry).

I am not really sure how to figure out that the current sensor is connected to ADC ... . Maybe through "resource" and "status" command?

CLI resource:


CLI status

Trying to find the correct wiring diagram or specifications for all of the different revisions of the Diatone stuff is a nightmare. One diagram I found showed the F40 with ESC telemetry on RX6, which is why I suggested to give it a shot.

Based on your output, it looks like ADC 2 is used for the current sensor and mapped properly. The only other thing I can think of is you need to adjust your offset for some reason. Try following that procedure in the video I linked above and see if that helps.

Have you tried Betaflight on this board? Does the current sensor work properly there?

Sadly I have no clamp meter or watt meter ... . So I cant do the method in the video.

I have a spare FC here (exactly the same Mamba F405 MK2 & F40 MK2 ESC Target FURYF4OSD). I flashed latest BF and calibrated current scale to 3100 having same value on my circuit tester and on BF configurator (0,06 A with 6s battery in idle). I am not able to do this on INAV since scale needs to be >10000 with battery in idle mode which is not possible (Max value is 10000). Setting scale to 10000 shows 1,7 A in INAV and 61 mA on circuit tester.

I am clueless .... ?!

Maybe this have nothing to say, but on BF current meter is assigned to C03 and RSSI to C02. In INAV it is current meter to C02 and RSSI to C03.

(09-Apr-2021, 09:30 PM)Julez Wrote: Maybe this have nothing to say, but on BF current meter is assigned to C03 and RSSI to C02. In INAV it is current meter to C02 and RSSI to C03.

That could certainly be an issue...

iNav has a target for MAMBAF405US with the current sensor mapped properly. Have you tried that?

I am so confused. Target "MAMBAF405US" works perfectly. Scale of ~345 gives very nice result with my circuit tester .... . Now i need to test if other stuff is working with new target.

Please answer me one last question, just to be sure. Did I miss something "basic" and BF target is not the same target in INAV ?! Or is this kind of a bug?!

Thank you very much!

I think the FURYF4OSD target was just used for an older revision, as there is also a MAMBAF405US Betaflight target. It is kind of a mess with all of the different hardware revisions released with the same name and no documentation.

Glad you got it working! Happy flying.

(09-Apr-2021, 06:14 PM)V-22 Wrote: iNav current/voltage scales are a factor of 10 higher than BF. 1100 sounds correct.

Try 1150 for the current scale. Fully charge a pack, fly, then recharge the pack and compare the amount recharged with the mAh used from iNav.

Haha. I am going to stop answering INav questions.

Just to have this complete:

The MAMBAF4US target does not work with my Mamba F405 MK2 (HW Rev. 3) FC. Resource mapping is f**** up completely. At least we could figure out that the current sensor is not working with FURYF405OSD target since resource mapping for C02 and C03 is wrong (needs to be the other way round).

I try to open a INAV bug report and try to clarify if the resource mapping for FURYF405OSD ist just "wrong" or belongs to another FC/HW-Revision. If this fails i try to build my own target ... .

Thank you!

Not that this helps you but I recently installed a new HGLRC Zeus F722 stack and the manual shows the settings for the voltage and current perimeters.  The previous stack is had (Lumenier LUX7) also showed the settings in the manual.  I don’t understand why more manufacturers don’t do this as it would sure make life easier.....