# Issue with Servo Control via Navigator in Single-Thruster Underwater Glider Using ArduPilot

**URL:** <https://discuss.bluerobotics.com/t/issue-with-servo-control-via-navigator-in-single-thruster-underwater-glider-using-ardupilot/20619>\
**Category:** Cockpit\
**Tags:** ardusub, mapping, cockpit\
**Created:** [June 11, 2025, 5:32am UTC](https://discuss.bluerobotics.com/t/issue-with-servo-control-via-navigator-in-single-thruster-underwater-glider-using-ardupilot/20619 "2025-06-11T05:32:43Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\
**Post date:** [June 12, 2025, 2:43am UTC](https://discuss.bluerobotics.com/t/issue-with-servo-control-via-navigator-in-single-thruster-underwater-glider-using-ardupilot/20619/3 "2025-06-12T02:43:14Z")

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Hi @Njanaprakasam, welcome to the forum 🙂

Can you add a couple of [Plotter widgets](https://blueos.cloud/cockpit/docs/latest/usage/advanced/#plotter-widget) in Cockpit, and set them to [`RC_CHANNELS.chan1_raw`](https://mavlink.io/en/messages/common.html#RC_CHANNELS) and [`SERVO_OUTPUT_RAW.servo1_raw`](https://mavlink.io/en/messages/common.html#SERVO_OUTPUT_RAW)? That should allow you to see the input the Navigator is receiving (e.g. whether your communication hardware is working and set up correctly), and the pulse durations it is trying to output to the ESC (e.g. whether the autopilot is configured as you want it to be).

> [@Njanaprakasam](#):
>
> Channel 1 does not respond to transmitter input after arming the setup in BlueOS.

I believe arming only affects `MotorN` values for the servo output functions, so this shouldn’t be relevant - all other output types are active at all times.

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By the way, I am curious how this is connected, and whether you’re testing it in air or water.

> [@I want to operate a t200 thruster with flysky i6 tx and rx . how to control](https://discuss.bluerobotics.com/t/i-want-to-operate-a-t200-thruster-with-flysky-i6-tx-and-rx-how-to-control/11229/2):
>
> It’s … worth noting that water absorbs radio waves quite quickly, so radio control is only really appropriate for surface vessels, or an underwater vehicle with a tethered connection to a buoy/vessel at the surface which receives the radio waves.

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