I discovered that on my new build the volt meter wasn't correct in the OSD, reading about .6 volts low.  So I did what I did in my previous quads and went into the power section of BF.  I hooked up my battery checker to the battery and matched the reading from the battery checker in BF by making changes to the scale setting.  Well, when I flew today the reading in OSD didn't change during the whole flight, staying at 15volts the whole time with a 4s battery.  When I got done flying I put a 3s battery on the quad and it still read 15volts in the OSD.  Later I hooked up to BF and the same thing happened, 15volts all the time.  Clearly I did something wrong in BF, as the voltage was reading was changing during a flight before I made adjustments, the values were wrong, but it did display a reading that went down as the quad was flown.  And the reading was around 11volts with a 3s battery as well.

So what did I screw up and how do I calibrate the voltage reading in BF.

Thanks....

Can I see a photo of the battery tab? Dump file and how is the FC power wired? I assume your wiring is lipo to FC and not using some kind of external pdb or regulator?

(24-Aug-2019, 09:43 PM)voodoo614 Wrote: Can I see a photo of the battery tab? Dump file and how is the FC power wired? I assume your wiring is lipo to FC and not using some kind of external pdb or regulator?

You're on to it VooDoo.  I'm running a 4in1, and so wiring for this is a little different than an AIO.  

I guess I need to know which pad to solder the BAT + from the 4in1  onto the FC

Looks like BAT+ from the ESC goes to Uart RX6 on the FC, (matek F722-SE) maybe??  And then select ESC in ports on BF?





4in1

fc

So there is two ways you can do this. I am assuming that your pigtail is on the 4in1.

Just run bat from 4in1 (as you circled) to the Matek Vbat or the lipo + pads. Of course ground is ground.

The second way to do this is use ESC telemetry. If you already have esc telemetry wired, it is just a setting in the battery tab.

(25-Aug-2019, 05:35 AM)voodoo614 Wrote: So there is two ways you can do this. I am assuming that your pigtail is on the 4in1.

Just run bat from 4in1 (as you circled) to the Matek Vbat or the lipo + pads. Of course ground is ground.

Well that won't work as the 10v from the ESC to power the FC is fed in on one of the ESC pads

The second way to do this is use ESC telemetry. If you already have esc telemetry wired, it is just a setting in the battery tab.

That is what I was thinking above, but didn't want to put that on RX6 without knowing how that would play out.  On the 4in1 wiring diagram of the FC, the third choice kind of indicates this.  Then set up Uart 6 in BF with ESC for the sensor input, and in the power tabs to select Voltage meter source as ESC Sensor.  

I haven't put a multimeter on the BAT + wire yet, but I'm guessing it is battery voltage, just with little current capability.  Since this is a 4s system, can a Uart handle 17volts?

At this point I'm getting the 10 volts from the 4in1 to the FC that is powering it.  That doesn't work too good for knowing how much battery you got left on a flight.


 

You can also remove the 10V to the FC ESC pad. You can just wire BAT to the ESC pad or lipo pad instead on FC.

In your last choice, how you diagram will work. You are not putting BAT to an UART. The blue wire is telemetry. It is just data for RX6.

You can also remove the 10V to the FC.

The bat+ wire is red, current is yellow and telemtry is blue.  So the bat+ isn't telemetry per se. 

The ESC directions say to wire the bat + to the voltage monitoring pad on the FC.  Any idea which pad that is?

I'm trying not to wire to the FC battery input pads as that will garbage up the looks a little.  But if I have too I will

This will power the FC too. 

Thanks VooDoo....I decided to just do a jumper from the ESC battery pads to the FC battery pads.  It looks ok and it was a quick and easy solution.  Thanks again

That will work.