No GPS today!

s7nthson · Oct 13, 2015

I went out this evening before darkness to get in a little flight time. None, I had 13 satellite no GPS lock. I want fly in that park without GPS. This happened after the 1.2 update, I have flown there since April 2015.
I am baffled beyond belief, I waited roughly 10 to 15 minutes. The darkness took over and I called it a night.

RolandS888 · Oct 19, 2015

How is it that you can have 13 sats and no lock? Can someone explain that to me.
I guess i have a similar situation..
I just did the M8N gps mod and sure enough after a time standing outside (night time, so not flying) for testing i can acquire 20 sats.
BUT, at times during acquisition it may show 12, 14, 15 or more satellites and still says "Waiting for GPS".
And when I do have 17 or 18 satellites and I place my hand over the GPS the sats drop off to maybe 14 or 12 (as expected) and the controller goes to "Waiting for GPS"...why?? I still have > 10 satellites, and HDOP < 2 all the tiime, at times it was 1.0 wiith 19-20 sats.
Is there a satellite status that is 'able to be seen but not available for position confirmation' or something like that.
Is Solo actually using the data from the extra Glonass sats from the M8N, because I feel that they are being reported but not being used for position lock.
How is it that you can have so many sats on the screen but still not have lock.
So I guess I have the same question as s7nthson above, but for a slightly different reason.
Does anyone know why this is.?

Jubalr · Oct 19, 2015

The requirements for Solo to 'Lock' is more stringent than many other MRs. This is due to the fact that it is marketed as a monkey could fly it. Therefore, new pilots are going to be more reliant on GPS. So it is not the # of satellite signals that is as important as the quality of the signals. It is also not just dependent on HDOP either.

HWA · Oct 20, 2015

I can't get GPS lock Oct 15 at a new location then where I usually fly. At first I thought it was the shade cast by the early sun raise, move it away from a shaded area try again and nothing. Waited at lease 5 mins nothing. So, I did a compass calibration, power cycle it once and its works. GPS lock like within 1 min. Maybe try Compass Calibration it works for me. Good luck.

Retired2Fly · Oct 20, 2015

Jubalr is right. The quality vs quantity of GPS signal is important. This week, geomagnetic storms produced b unusual solar activity are especially high so some may experience getting lock on their solo. Giant 'Hole' in Sun Is 50 Earths Wide

User Name · Oct 20, 2015

RolandS888 said:
How is it that you can have 13 sats and no lock?

As Jubalr said, it depends on the quality of the lock. Ideally, you want to be picking up satellites across the sky. If you're picking up multiple satellites all from the same area, the quality of the triangulation will be poor. Here's a quick diagram:

For each satellite, the receiver knows it's a fixed distance, somewhere on a radius around that satellite. When you have 2 satellites, those radii will cross in two locations, so the receiver would know it's in one of those two locations. With a third satellite, the location on the radius of the third would intersect one of the two intersections of satellites one and two, allowing the receiver to know exactly where it is.

The problem when all the satellites are bunched up in one area of the sky is that the intersections are much less defined. Technically, you only need 3 satellites for a 3d fix, but for a good fix, they'd have to be as spread out over the sky as possible. Also, satellites directly overhead don't do much good. And for redundancy, you want multiple satellites in case one drops out. This is why you can have 10 or more satellites and still not have an accurate enough lock for the Solo to allow a flight, and other times, 6 or 7 is all it takes.

Rich · Oct 20, 2015

@User Name has it right! It's all about quality and stability of the fix. Not just the number of satelites or their signal strength.

I sometimes think that 3DR could allow different levels of signal quality. Perhaps more of a lesser quality for general flying, but then a more accurate geometry to allow smart shots to be used.

Perhaps this may add to confusion, or it could allow the Solo to take off an fly with no problems, but then get better location when needing greater accuracy for smart shots.

Scientific11 · Jul 9, 2016

Since having solo I have only been up to 13 sats, I would like to have more, maybe only because my coworker dji locks in on 16 before it even takes off, HELP ME GET MORE!

Jubalr · Jul 9, 2016

Scientific11 said:
Since having solo I have only been up to 13 sats, I would like to have more, maybe only because my coworker dji locks in on 16 before it even takes off, HELP ME GET MORE!

That's about the max for Solo. I believe the DJI also receives Russian GLONASS birds as well and may see 18 or more.

DJ Wes · Jul 9, 2016

A $30 fix can be found with one of these. Mini uBlox M8N. Here's a vid on how to do it.

fpvsteve · Jul 10, 2016

Scientific11 said:
Since having solo I have only been up to 13 sats, I would like to have more, maybe only because my coworker dji locks in on 16 before it even takes off, HELP ME GET MORE!

Have a look here:

Get the maximum out of your 3DR Solo GPS - Hackster.io

Scientific11 · Jul 10, 2016

fpvsteve said:
Have a look here:

Get the maximum out of your 3DR Solo GPS - Hackster.io

Thanks Steve, but I'm not ready to get into all that. I'm not that skilled. But as the photo shows, 23 sats sounds great

PdxSteve · Jul 10, 2016

My buddy has a P4 and always has 2x more satellites show up on his, but my solo performs better than his

It's just a number. You should be looking at HDOP, not the number of satellites. The number of sats doesn't tell you crap about the quality of the signal or lock. Solo is more picky about the satellites it uses too and doesn't just lock onto everything up there just because it's there.

Scientific11 · Jul 10, 2016

PdxSteve said:
My buddy has a P4 and always has 2x more satellites show up on his, but my solo performs better than his It's just a number. You should be looking at HDOP, not the number of satellites. The number of sats doesn't tell you crap about the quality of the signal or lock. Solo is more picky about the satellites it uses too and doesn't just lock onto everything up there just because it's there.

Man Steve brother, you are awesome on information, now what's HDOP and where is that on the solo app/controller

DJ Wes · Jul 10, 2016

The M8N's from this link are already flashed with the correct settings for Solo:

Mini uBlox M8N GPS GLONASS W/ (35x35mm) Mounting backplane and Compass V2

It's just a remove and replace along with a couple of wire slices and that's about it.

PdxSteve · Jul 10, 2016

Scientific11 said:
Man Steve brother, you are awesome on information, now what's HDOP and where is that on the solo app/controller

Here's a good read: http://www2.unb.ca/gge/Resources/gpsworld.may99.pdf

In the app, if you touch the very top line of parameters (battery, etc) it will open a 2nd line that shows HDOP and other useful things.

Qwallabear · Jul 29, 2016

DJ Wes said:
The M8N's from this link are already flashed with the correct settings for Solo:

Mini uBlox M8N GPS GLONASS W/ (35x35mm) Mounting backplane and Compass V2

It's just a remove and replace along with a couple of wire slices and that's about it.

Which cable configuration is needed from the Readytoflyquads.com selection for the 35x35mm Ublox m8n?