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Help re: voltage telemetry
#1
Hello all:

I am running Betaflight on an f3 board.  I connected the Vbat inputs on the FC to the VCC and GND outputs on my Matek PDB.

When I connect a battery and connect Betaflight it appears to be showing the correct voltage on my computer.  However, using my Taranis X7 with telemetry when I detect sensors and create a VBAT sensor, it shows the voltage as much lower (around 10 volts).  

First, why would there be a discrepency between the Betaflight indicated voltage and the telemetry voltage indicated from telemetry?  Shouldn't they be the same thing?

Second, any help with moving forward would be much appreciated.  

My goal is to use logical switches and telemetry to have audible voltage warnings.

Thanks so much, Steve.
#2
OK - more questions on the same issue - hopefully someone will help me Smile

On the Taranis, when I go to the telemtry screen and select the voltage there is a "ratio" that I can select and change.  Using this I can correct the voltage BUT is this the correct way to do this?  When I modfy this setting it changes the voltage displayed by the telemtry variable but this doesn't change the voltage displayed in the Betaflight screen.

In Betaflight, under the config tab, there is a "battery voltage" area.  Within this there is a "voltage scale" that can be modified.  Should I be tweaking this?  When I modify this it changes the voltage displayed in the Betaflight screen BUT doesn't change the telemetry voltage on the Taranis.

Any help or even partial explanations would be much appreciated.

Thanks, Steve
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#3
Hi Steve.

Its a matter for calibrating it yourself.
You should think of it as separate things, you have the voltage sensor reporting with a certain value.
This value has nothing to do with volts, i believe the way it works is that the software check how long to takes to charge a certain capacitor and relate this to how long it would take to charge it with 5v.
Whatever your Taranis displays or whatever Betaflight shows is derived from this value and is displayed in volts.

So yes, plug in the battery and check what the actual voltage is with a multi-meter.
Adjust the voltage scale if needed in betaflight with voltage scale. (Though, the default value should not be off by much)
Then adjust the ratio on your Taranis the same way.

For good measure, test it with a full, half emptry and "empty" Lipo and verify that the whole range is correct.
Check out my videos @ http://www.youtube.com/Marcelfint and let me know what you think!
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#4
Thank you Flint - I will work on the calibration.  In the meantime I have been researching this and I think my issue is that I did not connect telemetry correctly.  I assumed that Sbus was both input and output but it looks like Sbus is receiver output and I need to use a seperate UART to get telemetry back to the RX.

Again - I appreciate any and all help.   Big Grin  Steve.
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#5
You can't use the same UART twice. There some exceptions when you can, but in your case you should wire SBUS to UART# RX and S. Port telemetry to UART## TX.

As far as telemetry, there has been report of telemetry bug for XSR and X4RSB. If you have either of these, you should consider updating RX firmware.
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#6
Which RX are you using? I have the XSR and needed to flash the latest firmware before I was able to read telemetry correctly.

The bit that took me a while to figure out with the Taranis X7 was you need to flash using the port on the base (near the SD card slot), pin order was GND, 5V, S.Port (closest to SD slot).
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#7
Thanks much for all the advise.  I do have the XSR RX.  I have ordered another of that small 5 pin so I can make an adapter cable to flash the RX firmware.  

I'm not giving up!!!!!

I will keep you updated after the next Amazon delivery!

Cheers, Steve
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#8
Guys i need help urgently. I have a flysky i6 (rebranded as longing-ly brand) transmitter and i wanted to bind it to my new bfight 210 drone. I struggled with the betaflight board, as no signal was detected by the pwm flysky reviewer on the board. I tried everything twice and suddenly the board made a whine, (coil whine ish) very softly and now when it boots it does the first noise, but repeats the esc sounds continually. My 4s lipo is at 48% 14 V and should be a problem right? I can plug the flight controller into the laptop, (into betaflight config) and then it boots with the battery. But the battery connected alone now makes me afraid, could i have broken something from simply rebooting the board a lot? I fiddled with the inputs somewhat,
Any (really any) help would be greatly appreciated as i fear i fried my board, as unlikely as it seems to ti me
Info
Bfight 210 BNF version /w AFHDS 2A reciever
Dshot 30A blheli esc
Omnibus f3 (maybe) flight controller
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#9
(18-Aug-2017, 08:10 PM)PikoMeter Wrote: Guys i need help urgently. I have a flysky i6 (rebranded as longing-ly brand) transmitter and i wanted to bind it to my new bfight 210 drone. I struggled with the betaflight board, as no signal was detected by the pwm flysky reviewer on the board. I tried everything twice and suddenly the board made a whine, (coil whine ish) very softly and now when it boots it does the first noise, but repeats the esc sounds continually. My 4s lipo is at 48% 14 V and should be a problem right? I can plug the flight controller into the laptop, (into betaflight config) and then it boots with the battery. But the battery connected alone now makes me afraid, could i have broken something from simply rebooting the board a lot? I fiddled with the inputs somewhat,
Any (really any) help would be greatly appreciated as i fear i fried my board, as unlikely as it seems to ti me
Info
Bfight 210 BNF version /w AFHDS 2A reciever
Dshot 30A blheli esc
Omnibus f3 (maybe) flight controller

The reason i think something is wrong is asbfor the first time after the whine all the boards LED lights are very dim, until i plug it into the pc.

Oh and apologies for posting here
I really dont know how to start a new thread as i am new here.
Thanks
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#10
(18-Aug-2017, 08:12 PM)PikoMeter Wrote: The reason i think something is wrong is asbfor the first time after the whine all the boards LED lights are very dim, until i plug it into the pc.

Oh and apologies for posting here
I really dont know how to start a new thread as i am new here.
Thanks

At the top right of any section (I'd suggest "Beginner Questions") is a button "Post Thread". This button lets you start a new thread.

I'm not sure what to say about your problem as I have no idea what board you are actually using. Can you

a. Start a new thread
b. Provide links to the quad in question
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