Frsky R8 PRO receiver AIN2 port not working?

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spadeadam
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Frsky R8 PRO receiver AIN2 port not working?

Post by spadeadam » Fri Sep 11, 2020 3:13 pm

Hi all,

I am trying to monitor my 4s LiPo battery connecting it via a FBVS-01 (3S connector which gives 6:1 ratio) To the AIN2 port of my R8PRO receiver.
When I discover sensors I only get a A2 voltage reading of 1.7V (ratio set to 19.4 which is 6 * 3.3)
I have measured 16.4V going into FBVS-01 and am getting 2.4V coming out which is fed into Gnd and AIN2 of the R8 PRO
When I try this with my RX6R receiver I get an A2 of 16.4V which is correct.
I have tried 2 x new R8PRO’s with a X9D Plus 2019 and Horus X10S express both running Access 2.1.0
Can anyone help me as I am probably missing something simple
The receiver is being powered via a separate 5V NiMh battery


Carbo
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Re: Frsky R8 PRO receiver AIN2 port not working?

Post by Carbo » Sat Sep 12, 2020 8:07 am

There is an (useless) A2 voltage in telemetry, but FrSky RX8Rpro have no AIN2 port at all. Where did you connect FBVS-01?

jtaylor
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Location: Wexford (Pittsburgh), PA

Re: Frsky R8 PRO receiver AIN2 port not working?

Post by jtaylor » Sat Sep 12, 2020 3:07 pm

He is talking about the Archer R8 PRO which does have a A2 input.

I don't have one, but the instructions read like it has a 10 to 1 voltage divider built in and can take an input to 36 volts directly and doesn't need a FBVS-01 or voltage divider. Perhaps somebody that knows for sure can comment as I would hate to see somebody burn it up by putting in more that 3.3v if it can't take it. Below is from the manual:

Voltage Measurement Range via AIN2
(External device): 0-36V
(Battery Voltage Division Ratio: 1:10

Jim

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Kilrah
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Re: Frsky R8 PRO receiver AIN2 port not working?

Post by Kilrah » Sat Sep 12, 2020 3:48 pm

Manual indeed suggests that the divider is built in on that RX.

spadeadam
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Re: Frsky R8 PRO receiver AIN2 port not working?

Post by spadeadam » Sun Sep 13, 2020 6:20 am

Thank you all for your quick replies, I will try connecting my LiPo directly to the AIN2 and keep my fingers crossed that no smoke appears:)

It would be nice to see a circuit diagram of the receiver


spadeadam
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Re: Frsky R8 PRO receiver AIN2 port not working?

Post by spadeadam » Sun Sep 13, 2020 2:23 pm

I can confirm that connecting a 3S or 4S LiPo directly to the AIN2 port works ok and gives a A2 telemetry reading corresponding to the LiPo voltage.

Saves using a FBVS-01 or voltage divider

Thank you all

jtaylor
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Location: Wexford (Pittsburgh), PA

Re: Frsky R8 PRO receiver AIN2 port not working?

Post by jtaylor » Sun Sep 13, 2020 9:41 pm

Thanks for confirming.

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youngstar
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Re: Frsky R8 PRO receiver AIN2 port not working?

Post by youngstar » Tue Oct 13, 2020 11:07 am

Many thanks for that :D not tried my R8 Pro yet!


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