[hwh]

The Chinese are producing a tiny GPS that they call the "OPGPS".  It has nothing to do with the OP/LP projects and the only thing "OP" about it is the connector is the correct one to plug into a revo.  Because they don't have flash memory to store settings they can't be used with a cc3d despite what the sellers say.

They have either a design or manufacturing defect in them that makes them run hot. Sometimes very, very hot.  The one pictured below melted like this after running about 15 minutes.  I've heard of others that did the same thing including one of the developers.

[darkdave]

I was having a debate with Xfce about including flash memory in our line. He also omited the flash memory and I asked him not to, but he insisted we don't need them. Can you comment?

What exactly does the flash memory in the OPGPS do? Store settings?

[hwh]

I can see where it might be confusing. If I were making V9 gps units I wouldn't populate the flash chip. The flash xfce is talking about is (or was) a big flash that was intended to be used for in-flight logging in a later release of the v9 gps firmware.  That function was never implemented (it never will be now) and the flash on the v9 isn't used.  It was hooked up to the STM32F0 cpu on the v9, not the ublox module.  The STM32F0 cpu configures the uBlox module with the proper settings every time it starts up so the v9 doesn't need a flash memory to work with both the cc3d and revo.

On most other gps units there's a small (I forget, a few hundred or thousand bytes) flash memory that's hooked directly to the ublox module that it uses to store settings like baud rate, protocol (NMEA or uBlox), etc...  For a revo class FC it's not necessary because the revo has autoconfig built into it's firmware that configures the gps each time it starts up.   For a cc3d there wasn't room for the autoconfig firmware so the gps has to be configured by hand before it can be used as shown in the wiki https://librepilot.atlassian.net/wiki/display/LPDOC/Configure+a+GPS+for+CC3D .   The gps has to have a flash to store the settings to work with a cc3d.

[hwh]

For anyone who's curious, this is the inside of the bad gps.  The voltage regulator literally burned up.

[startrek66]

Thanks.  But were  can find gps v9?

Inviato dal mio SM-G800F utilizzando Tapatalk

[Mateusz]

Thanks.  But were  can find gps v9?

• Original OP GPS v9 is not produced anymore, it is supported in firmware because LibrePilot is a fork of OpenPilot.
• It seems that most of people that actually want GPS usually have other problems with tunning or calibration and fall into this fallacy thinking that adding GPS will somehow magically solve their problems.
  This will never happen, even CC3D alone should fly nice and stable (some links to movies with just CC3D or Atom, not even Revo) https://forum.librepilot.org/index.php?topic=1893.msg13716#msg13716
  For GPS to be of ANY use, aircraft must fly perfect before, and all (with no exceptions) sensors must give good data, if that is not the case things will get only worst with GPS period.
• There are many way cheaper DJI Naza compatible GPS alternatives on the market, that have the same functionality as OP GPSv9. Those DJI Naza compatible GPS units have both GPS and Mag and use single cable protocol that just uses one port on Revo to send GPS and Mag samples. Those are supported in "next" development branch of git repository. Both GPS+Mag on one cable is exactly what OP GPSv9 was doing. If you want higher quality GPS then there are plenty of Ublox modules on the market with nicer better quality antennas (more resistant to multipath reflections). In all those cases you just need to add JST-SH 1.0 4pin connector at the end (easy to find on ebay).
  

Most problems come from people a) ignoring wiki and not calibrating sensors / tunning aircraft b) thinking GPS alone will do miracle. In fact even mobile phones use dozens of other sensors to improve position estimation in your device. It is never GPS alone, as that has couple of meters of error. For accurate positioning other data are required to be combined with GPS in order to get a good position estimate

[Mateusz]

About naming, Chinese cloners would probably sell a vacuum cleaner as Librepilot Vacuum Cleaner if that would boost their sells up, claiming that it runs LP firmware. Or call it Librepilot OpenPilot Revolution Nano Atom, my god it must be good as it has all those names that Google can find easily. Also if you buy GPS+Mag it doesn't mean that they actually sell you unit with Mag. Rule of thumb, don't buy anything because it is called like something. Name or brand/trademarks. in China seems to have no meaning.

[darkdave]

OP GPS v10 for sale here:

http://www.ebay.com/itm/222177336560?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

If you want v9 I can sell it to you too, just buy the v10 and send me an email at [email protected] and tell me you want the v9 instead.

[12many]

Thanks.  But were  can find gps v9?

• Original OP GPS v9 is not produced anymore, it is supported in firmware because LibrePilot is a fork of OpenPilot.
• It seems that most of people that actually want GPS usually have other problems with tunning or calibration and fall into this fallacy thinking that adding GPS will somehow magically solve their problems.
  This will never happen, even CC3D alone should fly nice and stable (some links to movies with just CC3D or Atom, not even Revo) https://forum.librepilot.org/index.php?topic=1893.msg13716#msg13716
  For GPS to be of ANY use, aircraft must fly perfect before, and all (with no exceptions) sensors must give good data, if that is not the case things will get only worst with GPS period.
• There are many way cheaper DJI Naza compatible GPS alternatives on the market, that have the same functionality as OP GPSv9. Those DJI Naza compatible GPS units have both GPS and Mag and use single cable protocol that just uses one port on Revo to send GPS and Mag samples. Those are supported in "next" development branch of git repository. Both GPS+Mag on one cable is exactly what OP GPSv9 was doing. If you want higher quality GPS then there are plenty of Ublox modules on the market with nicer better quality antennas (more resistant to multipath reflections). In all those cases you just need to add JST-SH 1.0 4pin connector at the end (easy to find on ebay).
  

Most problems come from people a) ignoring wiki and not calibrating sensors / tunning aircraft b) thinking GPS alone will do miracle. In fact even mobile phones use dozens of other sensors to improve position estimation in your device. It is never GPS alone, as that has couple of meters of error. For accurate positioning other data are required to be combined with GPS in order to get a good position estimate

Suggestion:  Someone needs to regularly skim the forums for great nuggets of information like the above and push it into the Wiki.  Far too much info is buried in irrelevant topics like 'bad Chinese GPS'.  Example:  as a new user I recently struggled with the V8 GPS lacking a magnetometer issue.  Nothing in the wiki, nothing obvious in GCS.  I.e. unnecessarily bad UX & easily avoidable.

Disclaimer:  This isn't intended as criticism, but as a suggestion for how to make the experience better for the next guy.  (I intend to help with the wiki once I better undeerstand what I'm talking about.)

[Mateusz]

Suggestion:  Someone needs to regularly skim the forums for great nuggets of information like the above and push it into the Wiki.  Far too much info is buried in irrelevant topics like 'bad Chinese GPS'.  Example:  as a new user I recently struggled with the V8 GPS lacking a magnetometer issue.  Nothing in the wiki, nothing obvious in GCS.  I.e. unnecessarily bad UX & easily avoidable.

Disclaimer:  This isn't intended as criticism, but as a suggestion for how to make the experience better for the next guy.  (I intend to help with the wiki once I better undeerstand what I'm talking about.)

1) I think this might be helpful for people reading above

This wiki https://librepilot.atlassian.net/wiki/display/LPDOC/Sensor+calibration explains that it is necessary to clibrate sensors in order to attempt INS31 navigation.
We have: accel, gyro, mag calibration steps. Baro gets calibrated in thermal calibration, but must be inspected in scopes if it works on your board.

What Magnetometers are supported is described here https://librepilot.atlassian.net/wiki/display/LPDOC/Aux+Mag+Setup+and+Calibration
Making wiki is a lot of work, and it's constantly improved.

2) About GPS without Mag

I think it makes sense if you come to the shop to buy GPS, that you're not getting Magnetometer. These are different sensors that measure different things.
It just happens fortunately for us, that some GPS units designed for RC models do include Magnetometer on-board. If they don't then you can connect external one HMC5883L over I2C bus to Flexi/I2C port.
See above for the link where it is described which magnetometers are supported and how they can be connected.

LibrePilot is just a software, and I belive user should have a freedom to choose hardware himself. Ideally it should be possible to use it with any hardware you want (my wish).


Update (some additional thoughts):

I personally perceive LibrePilot as a community owned project, so it belongs to everyone on the forum. It is free, transparent and open. It allows anyone to contribute, forks are also allowed but they usually split human resources which is not so good for the end user. It also takes a lot of time from people who are enthusiasts and kind to develop this software for us (big thanks here). Project's like that are just too big to be carried on by fewer people. I think they would greatly appreciate comments, writes-up in doc format (easy to upload/incorporate) from users using software and going through all steps. Any contribution also to Wiki can improve overall community experience. Writing documentation in my opinion is as important as adding new features and development, and great value for the project. If they have more input on Wiki from users then they have more time to develop awesome features

[12many]

Thanks @Mateuz.  Agree 100%.  The community here is really great & I'm impressed with the patient, helpful support I've seen and personally received for even the most ignorant questions I've posted.  And you're right, managing open source community projects is like trying to herd cats - best not to try!  Everyone wants to do the fun stuff, nobody wants to do the chores.

Not that it matters what I think, but I might suggest a minor change to the forum Q/A pattern that shouldn't be too much additional effort and reduce future inefficiency:

Ideally, instead of directly answering questions in the forum (which tend to get buried in chatter), if you 'heavy lifters' (you know who you are) could insert answers to common questions into the Wiki in the appropriate locations, then respond the the question like you did (see here on the wiki...).  This would result in either not having to answer the question again or at a minimum answering,  "RTFW on the wiki here...".  And it's a lot easier to improve the wiki in little chunks.  But the best thing is that new users (assuming that's what you want) will have a better experience, express less frustration, and ask less embarrassingly stupid questions like I do.

Example, @hth was super helpful on my GPS V8 vs. V9 question, even including pictures of each model.  If that had gone into the wiki, the issue is more or less closed, end of story and the wiki would be that much better for it.  I'd do it myself, but don't judge myself as yet qualified to go editing the wiki.  Not yet.

Ok, no need to go on and on.  The positive experience I've had here, despite weeks of user-error induced frustration, you guys inspire me to give back in some way.  I'm more a programmer than a copy editor, but I aspire to start contributing in some way soon.  Yeah, proof is in the doing, not the saying...

To the LibrePilot heavy-lifters out there:  Thank you for your efforts not only toiling over the programming but in helping with the chores.