Is it better to use Internal Compass/GPS or External Compass/GPS with Navio2?

Navio / Edge Hardware
1

Hi

I have a Navio2 Board.

For the moment, I am using the internal Compass and Internal GPS.
However, I wonder, whether it is better to use an external combined Compass/GPS instead.

What do you recommend?

Thanks you
Anis

2

hi

GPS:
you definitely don’t profit from an external GPS - except the redundancy in case of a failure;

COMPASS:
when your Navio sits right next to metal (wires, enclosures, etc) or high current wires are near (battery-esc-motor wires) - then your compass can be influenced by the magnetic field from that current; in such a case you should use an external compass or maybe comp/motor calibration can do the job too! (you can check your log files during a flight and check how stable your mag values are)
an external compass can improve your heading orientation;

1 Like
3

External compass is recommended. Even by Emlid if you are on the right dev forum.

https://groups.google.com/forum/#!topic/drones-discuss/eMpUBiytfi8

Use a well located, good antenna with the internal GPS. We see 18-20 sats and an HDOP of <1 with consistent performance.

4

Thank you both for your recommendations.

I am now using the internal GPS receiver with this antenna
https://emlid.com/shop/gpsgnss-antenna-mcx/

I feel that this antenna is not getting good enough number of satellites (7-10 SAT, and a bit high hdop>1.5) .

Will it be better if I use a better antenna like
https://emlid.com/shop/tallysman-multi-gnss-antenna/

Or is there any other recommendation for GPS antenna.

Thanks
Anis

5

I’ve been using this Usmile GPS/Compass for around 8 months or so, and it was by far one of the best investments I’ve made into my own project. I’ve seen it get 12-14 sats indoors within ~60sec. Outdoors almost always 18+ with hdop ~.8

The external compass makes a world of difference as well. Hope this helps :slight_smile:

6

second antenna will likely work better assuming you have them in right spot. elevate and/or get 7cm+ clearance from sources of potential interference. or so i have been told by those smarter than me.

7

Thank you.

Final question: is it safe to fly in GUIDED/AUTO/LOITER with GPS having 6 to 7 SATs, and hdop between 1.5 and 2.0?

Thanks
Anis

8

Technically it will work but you should be seeing more sats which leads me to believe you have something wrong or do not have clear sky. Too many bad stories of people trying to fly in/around houses/buildings using GPS modes. There are limitations. Being safe is a by-product of being smart.

9

Yes, I am in a building area but with open spaces.
I tried three types of GPS, the internal Navio GPS or two other external GPS.
The best I got is 10 SATs with 0.8 HDOP, which I think is not bad.
For Internal GPS, I got 7-8 SATS with 1.4 to 2.0 HDOP.

10

what you can try is build a small ground plane of aluminium/copper foil (a few cms square or round) and/or put the gps cable (not only the antenna as mentioned) away from (high) current cables; that could improve your sat signals…

11

Thank you

Today, I tried into an open football field and was able to make a very stable AUTO and GUIDED flight with 12 SATs and HDOP lower than 0.8.

I used an external GPS from CIROCOMM and seems to work fine with me so far.

12

great job!

13

External compass is recommended. Even by Emlid if you are on the right dev forum.

@coby I was talking about recommending 3DR GPS\Mag combo as an option for an external compass if one needs it, not about recommending external compass by default. @panky gave perfect explanation when external compass is needed.

14

@mikhail.avkhimenia thanks for clarifying.

15

Hi… could you please post a scheme of how did you connect the Usmile GPS/Compass on Navio2? Thanks in advance.