<p>RSSI = Received Signal Strength Indicator</p>
<p>The S(Smart) Port connects to the RSSI Pin on the flight controller for the telemetry information.</p>
<p>Only the SBUS out is necessary for most Kwads.</p>
<p><a href="https://i.sstatic.net/GmuIc.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/GmuIc.png" alt="Circuit " /></a></p>

CC BY-SA 4.0
2021-07-06T12:55:32.607Z
2021-07-06T12:55:32.607Z
Ira Watt
<p>Spec for mamba405: <a href="https://ardupilot.org/plane/docs/common-mamba405-mk2.html" rel="nofollow noreferrer">https://ardupilot.org/plane/docs/common-mamba405-mk2.html</a></p>
<p>Spec for R-XSR: <a href="https://www.frsky-rc.com/wp-content/uploads/Downloads/Manual/R-XSR/R-XSR%20ACCST%20-Manual.pdf" rel="nofollow noreferrer">https://www.frsky-rc.com/wp-content/uploads/Downloads/Manual/R-XSR/R-XSR%20ACCST%20-Manual.pdf</a></p>
<p>Looking at the two specifications the R-XSR requires both a SBUS In and Out however the mamba405 only has one SBUS connection. Moreover, the mamba405 spec says it only supports &quot;unidirectional protocols&quot;, does this mean I can just connect the SBUS out?</p>
<p>Thanks for any feedback</p>

<flight-controller><frsky>
Can you connect a mamba405-mk2 flight controller with a FrSky R-XSR receiver?
Ira Watt
# Can you connect a mamba405-mk2 flight controller with a FrSky R-XSR receiver?

(Asked by: username_0 on 2021-07-05)

Spec for mamba405: <https://ardupilot.org/plane/docs/common-mamba405-mk2.html>

Spec for R-XSR: <https://www.frsky-rc.com/wp-content/uploads/Downloads/Manual/R-XSR/R-XSR%20ACCST%20-Manual.pdf>

Looking at the two specifications the R-XSR requires both a SBUS In and Out however the mamba405 only has one SBUS connection. Moreover, the mamba405 spec says it only supports "unidirectional protocols", does this mean I can just connect the SBUS out?

Thanks for any feedback

**Tags:** flight-controller, frsky


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## 1 answers

### Answer by username_0 on 2021-07-06. Score: 1 | Accepted answer

RSSI = Received Signal Strength Indicator

The S(Smart) Port connects to the RSSI Pin on the flight controller for the telemetry information.

Only the SBUS out is necessary for most Kwads.

[![Circuit ](https://i.sstatic.net/GmuIc.png)](https://i.sstatic.net/GmuIc.png)


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