# PixHawk Mini with S-Bus Rx and Taranis Tx

**URL:** <https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705>\
**Category:** PX4 Autopilot\
**Created:** [September 4, 2018, 6:40am UTC](https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705 "2018-09-04T06:40:17Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Riz\_Hassan](https://discuss.px4.io/user_avatar/discuss.px4.io/riz_hassan/32/6325_2.png) [@Riz\_Hassan](https://discuss.px4.io/u/Riz_Hassan)\
**Post date:** [September 4, 2018, 6:40am UTC](https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705/1 "2018-09-04T06:40:17Z")

</div>

Hello Drone Code Community,

I am using the Pixhawk mini with S-Bus Rx, Taranis Tx on a quad copter. But I cannot get the AUX1 or AUX2 to Pass thru so i can use a servo. On QC Ground Control I can see the servos are responding but the actual servos are not moving (Yes, I have the UBEC connected to pin 8).

What am I missing?

Thanks.

---

<div class="post-metadata">

**Author:** ![rollys](https://discuss.px4.io/user_avatar/discuss.px4.io/rollys/32/2081_2.png) [@rollys](https://discuss.px4.io/u/rollys)\
**Post date:** [September 4, 2018, 11:31pm UTC](https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705/2 "2018-09-04T23:31:55Z")

</div>

- What airframe did you setup in QGC?
- Which specific receiver are you using? Doesn’t it have regular servo pins?

Good luck.

---

<div class="post-metadata">

**Author:** ![Riz\_Hassan](https://discuss.px4.io/user_avatar/discuss.px4.io/riz_hassan/32/6325_2.png) [@Riz\_Hassan](https://discuss.px4.io/u/Riz_Hassan)\
**Post date:** [September 5, 2018, 12:41am UTC](https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705/3 "2018-09-05T00:41:07Z")

</div>

Hi Rollys,

Air-frame is TriCopter.

Rx is FrSky X4RSB using bottom row pins for SBus (#4 Channel Pins).

Thanks.

---

<div class="post-metadata">

**Author:** ![rollys](https://discuss.px4.io/user_avatar/discuss.px4.io/rollys/32/2081_2.png) [@rollys](https://discuss.px4.io/u/rollys)\
**Post date:** [September 5, 2018, 2:38am UTC](https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705/4 "2018-09-05T02:38:19Z")

</div>

Did you see the [docs](https://docs.px4.io/en/airframes/airframe_reference.html) on this setup? The AUX ports may not be part of the airframe mixer:

Tricopter Y-  
Common Outputs  
MAIN1: motor 1  
MAIN2: motor 2  
MAIN3: motor 3  
MAIN4: yaw servo

You don’t need AUX port for servo. If you need more PWM ports, you can bind the Rx in [D16 SBUS](https://www.frsky-rc.com/wp-content/uploads/2017/07/Manual/X4R%20X4RSB%20CPPM.pdf) and use its pins for additional 2 servo outputs.

Good luck.

---

<div class="post-metadata">

**Author:** ![Riz\_Hassan](https://discuss.px4.io/user_avatar/discuss.px4.io/riz_hassan/32/6325_2.png) [@Riz\_Hassan](https://discuss.px4.io/u/Riz_Hassan)\
**Post date:** [September 5, 2018, 3:14am UTC](https://discuss.px4.io/t/pixhawk-mini-with-s-bus-rx-and-taranis-tx/7705/5 "2018-09-05T03:14:37Z")

</div>

Thank you. Yes I did see the docs, but didn’t realized that TriCopter does not support AUX servo use (Assumption is mother of all screw-ups!). I was planning to place a gripper servo that is why I needed Aux pass through.

Thanks again for your help.