startrek66

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Gps for Revolution
« on: August 09, 2016, 04:08:01 pm »
I want to buy a GPS for revolution board. I'm not interested in the autonomous flight, I'm happy to use the GPS just to maintain the position. I do not have much knowledge, and unfortunately there are many products that are sold with compatibility to fc revolution and with very different prices, and then you create the confusion. I ask you what are the minimum requirements that must have a GPS to be mounted on fc revolution and if there is a list of GPS products that have already been successfully tested.
Thanks in advance

f5soh

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Re: Gps for Revolution
« Reply #1 on: August 09, 2016, 04:24:13 pm »
Naza GPS is a good choice, original or clone like that:
http://www.banggood.com/Ublox-M8N-GPS-Compatible-with-DJI-NAZA-Lite-V1-V2-Flight-Controller-Phantom-1-2-Vision-p-991718.html
That allow GPS and also receive external Mag data using the same serial connection.

Naza GPS is currently supported using the Next branch, 15.09 release only support external mag from original OP GPSv9.

Mateusz

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Re: Gps for Revolution
« Reply #2 on: August 09, 2016, 04:43:30 pm »
Just one comment:

It is important to consider what GPS will be used for and why it is needed. I am perfectly happy without GPS for the type of flying I am doing right now. Altitude vario and it hovers more or less in place, I can let sticks for few seconds that is enough to put goggles on and tighten the head strap before it starts drifting.

  • If the GPS is needed to have stricter hold in position, despite wind blowing, or position roam function, or GPS assist for stable filming then yes, you want GPS and that's the way to go I guess.
  • On another hand, many people who actually ask about GPS, don't know it's much more complex to set up stuff, and it will NOT help or magically solve other problems they have. If the copter is not stable or flying great, adding GPS will not make things better. In those cases I would recommend fixing your build or tune instead of jumping directly into much more complex topic. Copter must fly be flying great in the first place to consider using GPS utilizing flight modes.

Something to think of :)

startrek66

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Re: Gps for Revolution
« Reply #3 on: August 09, 2016, 06:16:40 pm »
Thanks for your answers.
I agree that the GPS does not solve the stability problems . Luckily for me my quadcopter  is really stable with flight mode that I use usually ( attitude , altitude hold) . The gps interests me to take pictures .

With reference to naza gps clone I noticed that only has a cable while I saw other GPS models with two cables that connect to the Main and Flexi ports . What are the differences ? Thanks

Example gps one cable

 http://m.aliexpress.com/item/32630075400.html?productId=32630075400&productSubject=UBLOX-NEO-7M-NEO-7M-GPS-w-Compass-Stand-Holder-For-CC3D-Evo-CC3D-Revolution-Flight&spm=2114.46010408.3.67.sIkj1n&tracelog=wwwdetail2mobilesitedetail

GPS with two cables

http://m.aliexpress.com/item/32703991313.html?productId=32703991313&productSubject=U-blox-NEO-7N-GPS-with-3-Axis-Electronic-Compass-for-CC3D-Revolution-Flight-Controller&spm=2114.46010408.3.19.WjLEBX&tracelog=wwwdetail2mobilesitedetail


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« Last Edit: August 09, 2016, 07:26:31 pm by startrek66 »

f5soh

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Re: Gps for Revolution
« Reply #4 on: August 09, 2016, 07:20:59 pm »
Quote
That allow GPS and also receive external Mag data using the same serial connection.

Others GPS with 2 cables uses one serial cable for GPS and another I2C connection for Mag.
So with one cable that more simple, avoid I2C issues and flexiPort/mainport is free for RC Input use like DSM/Sbus

hwh

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Re: Gps for Revolution
« Reply #5 on: August 09, 2016, 08:42:55 pm »
« Last Edit: Today at 01:26:31 pm by startrek66 »
« Reply #4 on: Today at 01:20:59 pm »
It's usually a bad idea to edit a post after it's been answered.  It would have been better to put the links in a new post. f5soh will never see that you changed your post and others may ignore it because it was answered by f5soh in it's original form.

You can certainly buy a cheap GPS without a mag sensor like your first link and try to use the revo's built in mag sensor but that almost never works right.  You might get lucky and find that it has the sensor but no cable and be able to add a cable but even then you still have all the disadvantages of an I2C external mag.

Your second link has the connector for an I2C mag and should work fine.  I don't recommend buying them for two reasons: First, they take up both the main and flexi ports which limits your options for receivers, OSDs, etc...  Secondly, the I2C ones are often hard to get running reliably.

Following the advice you were given to get a DJI/Naza style GPS is the easiest, most reliable way to add a GPS.

Re: Gps for Revolution
« Reply #6 on: August 09, 2016, 08:55:26 pm »
All of these require you to solder a different connector on them.

Some GPSs have both a GPS and a mag.  Get one that has both.  This "aux mag" can be placed on a pole to get it farther away from the mag fields of the high current motor ESC battery wires.  That allows it to see the Earth's mag field without so much distortion.  You still need to twist all high current (battery, PDB, ESC, motor) wire pairs/triplets.

Some GPSs that have a mag, only have one cable.  Both GPS and mag signal are sent on the one cable.  That is what you should get because it does not need 2 ports on your Revo.  You will want those Revo ports for other things, like OSD, Sbus, etc.

Some of the GPSs that have only 1 cable do not even have a mag.  Stay away from those.

Generally, all of the GPSs that have two cables have a GPS and mag.  These can be used if you already have this type of GPS.  I have one and used to fly it a lot, but they use a different mag signal that is easier to corrupt if the cable is too long, etc.

If I recommend what I think is best right now, it is an authentic DJI GPS/mag.  They are about $70 (shipped, new) on eBay.
Edit: They seem to be cheaper now, down to $43 shipped, new.  I have not bought this, so buyer beware.
http://www.ebay.com/itm/DJI-GPS-Compass-Module-for-DJI-NAZA-M-Lite-Flight-Control-System-/251862698572

Next in line, I would get a DJI GPS/mag clone from eBay for about $22 (shipped, new) if you want cheap, but test it for several days as discussed here:
https://forum.librepilot.org/index.php?topic=449.msg15319#msg15319

In last place, but it still works is a simple uBlox GPS with an I2C aux mag (two cables).
« Last Edit: August 10, 2016, 10:48:12 am by TheOtherCliff »

startrek66

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Re: Gps for Revolution
« Reply #7 on: August 10, 2016, 12:06:20 am »
« Last Edit: Today at 01:26:31 pm by startrek66 »
« Reply #4 on: Today at 01:20:59 pm »
It's usually a bad idea to edit a post after it's been answered.  It would have been better to put the links in a new post. f5soh will never see that you changed your post and others may ignore it because it was answered by f5soh in it's original form.

You can certainly buy a cheap GPS without a mag sensor like your first link and try to use the revo's built in mag sensor but that almost never works right.  You might get lucky and find that it has the sensor but no cable and be able to add a cable but even then you still have all the disadvantages of an I2C external mag.

Your second link has the connector for an I2C mag and should work fine.  I don't recommend buying them for two reasons: First, they take up both the main and flexi ports which limits your options for receivers, OSDs, etc...  Secondly, the I2C ones are often hard to get running reliably.

Following the advice you were given to get a DJI/Naza style GPS is the easiest, most reliable way to add a GPS.

Of course you're right. I was changing my message while f5soh answered .

startrek66

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Re: Gps for Revolution
« Reply #8 on: August 10, 2016, 12:15:25 am »
Many thanks for your advice , from which I understood that add a GPS to revo is not a simple thing .
So what can you say about these products ?



From the video it seems easy to configure and use.

hwh

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Re: Gps for Revolution
« Reply #9 on: August 10, 2016, 01:10:18 am »
I'm not sure what you're looking for, the hardest way to hook up a GPS?  :)

The video shows buying a GPS, buying an FTDI adapter, downloading UCENTER, configuring the GPS for a cc3d instead of a revo, and then finally connecting it to the revo where it will erase the settings you just did and configure the GPS the way it needs it.  In fact, with the tiny "OP GPS" the video shows it doesn't remember any of the settings you do in UCENTER after a couple of hours without power applied anyway.  It has no flash to remember settings or mag sensor.  Those tiny GPS units also have a bad habit of melting as you can see from the attached pictures.

How is all that easier than buying the GPS we recommend and just connecting it to the revo?

Wagsy

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Re: Gps for Revolution
« Reply #10 on: August 10, 2016, 06:51:07 am »
Yep. setting up a DJI GPS is the simplest way.
Buy GPS, cut wires, add to a REVO plug, set board to use INS13/GPS, calibrate-set to external mag and fly.

startrek66

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Re: Gps for Revolution
« Reply #11 on: August 10, 2016, 08:54:05 am »
Ok. I search a good price and buy it or a dji gps clone. I ask help you for my choice. Thanks

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Re: Gps for Revolution
« Reply #12 on: August 10, 2016, 10:57:47 am »
I just ordered one of these apparently authentic DJI GPS for $43 shipped.  It looks exactly like my other authentic DJI, including all markings, screw placement, screw head type, etc.  It seems to be the real thing that the seller has sold for $80 in the past (according to the item sales history).

I will let you know if it is and if it passes my tests as well as my other authentic DJI GPS.

http://www.ebay.com/itm/DJI-GPS-Compass-Module-for-DJI-NAZA-M-Lite-Flight-Control-System-/251862698572
« Last Edit: August 10, 2016, 11:02:54 am by TheOtherCliff »

startrek66

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Re: Gps for Revolution
« Reply #13 on: August 11, 2016, 05:15:54 pm »
Found three models of gps. What is a good choice?
Thanks

http://m.banggood.com/Mini-Ublox-Neo-6M-GPS-For-CC3D-Revolution-Flight-Controller-wBuilt-in-Compass-p-1022655.html

 http://m.banggood.com/Mini-Ublox-7M-GPS-Module-for-CC3D-Naze32-Flip32-SP-F3-Flight-Controller-p-1042849.html

 http://m.banggood.com/Mini-Ublox-M8N-GPS-Module-NEO-M8N-GPS-for-APM-2_52_62_8-CC3D-SP-Racing-F3-Naze32-Flip32-PX4-p-1035454.html

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startrek66

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Re: Gps for Revolution
« Reply #14 on: August 11, 2016, 05:16:56 pm »
I just ordered one of these apparently authentic DJI GPS for $43 shipped.  It looks exactly like my other authentic DJI, including all markings, screw placement, screw head type, etc.  It seems to be the real thing that the seller has sold for $80 in the past (according to the item sales history).

I will let you know if it is and if it passes my tests as well as my other authentic DJI GPS.

http://www.ebay.com/itm/DJI-GPS-Compass-Module-for-DJI-NAZA-M-Lite-Flight-Control-System-/251862698572
How you test the gps?

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