# Can't arm the Sentinel Drone.

Source: https://forum.modalai.com/topic/3520/can-t-arm-the-sentinel-drone
Category: Development Drones (https://forum.modalai.com/category/44/development-drones)
Tags: sentinel
Posted: 2024-06-03 21:28:46 UTC by Emon_dey
Replies: 5 · Views: 1037

## Emon_dey · 2024-06-03 21:28:46 UTC

Hi:
I am trying to fly the Sentinel drone for the first time. In the, QGC, it is showing 'Not ready' and in the expansion of the error, I can see two things, 'Horizontal gps error is too high' and 'Obstacle avoidance is not ready'. I tried disabling gps and it shows 'Ready to fly' but the drone is not arming. Another thing I noticed, I don't have a 'voxl-px4.conf' file under /etc/modalai folder. Any direction would be greatly appreciated.

## Reply by Eric Katzfey (ModalAI staff) · 2024-06-04 14:52:51 UTC

@Emon_dey Can you post the output of `ls /etc/modalai`? Are you trying to arm in manual mode? There is a parameter named `COM_ARM_WO_GPS`. Is that set to 1?

## Reply by Emon_dey · 2024-06-05 23:35:57 UTC (in reply to Eric Katzfey)

@Eric-Katzfey I have uploaded the screenshot with output of ls /etc/modalai command ![Screenshot 2024-06-05 at 7.30.11 PM.png](https://forum.modalai.com/assets/uploads/files/1717630242180-screenshot-2024-06-05-at-7.30.11-pm-resized.png) 
I was able to arm and fly it in Manual model, the 'COM_ARM_WO_GPS' parameter value is set to 1.
In fact, I want to arm it in Position mode and it still shows a warning of 'Horizontal gps error is too high' and the error 'Obstacle avoidance is not ready'.

## Reply by Eric Katzfey (ModalAI staff) · 2024-06-06 16:46:06 UTC (in reply to Emon_dey)

@Emon_dey The file voxl-px4.conf is in that screenshot.

## Reply by Eric Katzfey (ModalAI staff) · 2024-06-06 16:55:37 UTC (in reply to Emon_dey)

@Emon_dey said in [Can't arm the Sentinel Drone\.](/post/17476):
> Obstacle avoidance is not ready

How is the parameter `COM_OBS_AVOID` set? Should be zero.

## Reply by Eric Katzfey (ModalAI staff) · 2024-06-06 16:57:07 UTC (in reply to Emon_dey)

@Emon_dey said in [Can't arm the Sentinel Drone\.](/post/17476):
> Horizontal gps error is too high

What happens if you set the parameter `EKF2_GPS_CHECK` to 1?