I am posting this help people make decisions, considering some new LP features that will soon be available.  There are several things about GPS/mag/FC/OSD/"new RC receiver protocols" that all interrelate:
- new hardware that needs an extra port
- new features that require a certain port
- current FC's that have too few ports to run some combinations of features
- new FC's with more ports

Remember: CC3D only supports UBX GPS, and no mag at all, and the GPS is only for displaying current location; not for flight modes.

Next release will have support for external I2C mags.  That means that all (all of the ones I have seen) of the cheap GPS/mag units for APM and PixHawk (they are all uBlox/HMC5883L) will work with just some different connectors soldered on.  NB: some of the older APM GPS/mag units require 3.3v and that means soldering a jumper wire on it or using an external 3.3v Regulator.

Beware of the tiny OP GPS units being sold on eBay and elsewhere for about $12.50 shipped.  They do not have storage for the GPS settings so they do not work with CC3D because CC3D does not do GPS auto-configuration.  They also probably don't have a mag.  They should work fine on Revo+ class FC's. (Revo or Nano or Sparky2).

There is a different tiny $15 GPS on eBay that is Neo7 and has a mag.  It should work well with Revo+ (Revo+ has GPS auto-config).  Unknown if it stores settings permanently (only required for CC3D).  Requires soldering some connectors.

There are some larger $19 GPS units on eBay that already have an OP / LP / JST-SH-1.0mm connector.  They usually have a mag, but it is not wired.

The I2C external mags (aux mag) in these GPS units use a separate port (in addition to the GPS port).  You will run out of ports on your FC if you want to do too much at once and have an FC that does not have many ports.

We have found a minor issue with packets occasionally being dropped inside the OP GPS V9.  I mention this because a DJI GPS is almost the same price as an OP V9 GPS, and I would want to know about it if I were going to buy a V9. (OP GPS V9 code is probably not going to be fixed unless someone out there decides to take up the challenge.  This issue may be related to the CC3D GPS baud rate issue, 19200 max.)

Using an OP GPS V9 (because it has an external mag built in) will free up a port, but these are hard to come by as originals have been hit and miss at the OpenPilot store, and I have not seen clones.  They seem to be in stock for $60 plus shipping right now at the OpenPilot store.

The DJI GPS/mag which currently goes for about $75 shipped (authentic DJI) on eBay (and way cheaper than that for a not-so-good clone) will very probably also be supported in the next release.  It is just barely possible that DJI will change their GPS/mag in the future to make it incompatible with the current protocol (because their current obfuscated protocol has been deciphered).

The next release should have support for TauLabs/dRonin "Sparky2" flight controller.  This FC has an extra I2C port and the ports it has are a little differently organized (it also has the same updated sensors as Nano).

Currently all the new RC receiver protocols (SRXL, Hott*, ExBus) require FlexiPort.  For Revo and Nano, the FlexiPort is also the only port that can do i2C aux mag, so neither Revo or Nano can do a new RC receiver protocol and I2C aux mag at the same time.

Revo and Nano can't do GPS + I2C aux mag + OSD (not enough ports) or even S.Bus + GPS + I2C aux mag (S.Bus requires MainPort on Revo and that leaves only one other port for GPS or I2C aux mag).

Sparky2 can do all of that put together S.Bus + GPS + I2C aux mag + OSD, but I don't know and I worry that you may have to give up one of "GPS or I2C aux mag or OSD" if you want to use one of the new RC receiver protocols.

Sparky2 has a solder jumper option to send 3.3V to the RC receiver (DSM satellite people know about this).

Nano of course doesn't have telemetry, so if you need telemetry you are probably better off with Revo or Sparky2.


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Will there be a way in the future to use Sbus with GPS and I2C aux mag in the future? I only ask because I'm not wanting to add weight by having to add an Sbus to CCPM converter or adding extra wires using PWM.

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