Flip 1.5 + Mini uBlox 6M GPS [Help Needed]

[adamlepp]

Hey guys, hoping someone can help me out. I just bought a Flip 1.5 and Mini uBlox 6M GPS from RTFQs. Are these two components compatible with each other? All I really need from the GPS module is position hold and return to home. If they are, what's the proper way to connect the two (which pin goes to which pin)?

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Thanks for any and all help.

Adam

 

[jhitesma]

You'll need to add at least the "pimp my flip" board from RTFQ since the Flip 1.5 doesn't have mag or baro sensors which are required for GPS. Even then the MW boards aren't great for GPS. There are a number of threads on here and in the beginner section going over it but basically you can get a kind of sort of usable position hold (Think 10-15 foot circle and about 5' altitude accuracy) with a LOT of tuning...and you might occasionally have a RTH that heads towards home. But overall the MW boards aren't well suited to GPS.

If you really want GPS then I'd say look at the APM if you want to primarially fly GPS and just guide the multi, or Tau if you want to actually fly and just occasionally use GPS. I've been using Tau lately and am really impressed at it's performance, it flies very well manually and semi-autonomously. From what I've heard APM is good at autonomous/semi-autonomous flight but not very good at manual flight. I haven't fully tested the GPS features on the Tau yet but it does altitude hold with no tuning and an older less accurate sensor WAY better than MW and Naze do with lots of tuning and newer more accurate sensors.

 

[adamlepp]

Thanks jhitesma for your response.

I actually do have the "pimp my flip" with mag and baro. Is there anything else I would need to make this work? I'm really looking for a low-cost solution (at least for now - I figured I can always upgrade later).

Thanks,

 

[jhitesma]

You'll have to reflash the sketch with it properly configured for all the sensors. Make sure you've got your name and contact info on the frame, GPS is a good way to learn about flyaways

That should be enough to try the POS Hold and RTH out, just don't expect miracles from them.

 

[adamlepp]

How do I plug the GPS into the Flip? The GPS has Gnd, VCC, SDA, SCL, RXD, TXD on each of the two ports. I'm assuming the TXD goes to RX on the Flip and that RXD goes to TX? Are the SDA/SCL channels used for anything?

 

[jhitesma]

Yes, you should just need to supply power to the GPS and then run RX from the GPS to TX on the FC and TX on the GPS to RX on the FC. Last I checked (a week or two ago) no build of MW supported I2C GPS so the SDA/SCL lines aren't used or needed.

I'm not sure which serial UART port is exposed on the flip though so you'll have to check with the documentation from RTFQ to figure out how to setup the config.h on that particular setup.

If you're having issues one thing you can try is using a "FTDI" adapter (or any other serial to USB adapter) to connect the GPS right to your computer and use the ublox u-center program to test it. Then you'll at least know for sure that the GPS is working and can focus on tracking down software issues if it's not working on the FC.

 

[adamlepp]

Thanks again jhitesma for all your help and advice - I really appreciate it.

I've tried just about everything to connect my GPS to the Flip. After some more research and Googling, I found a lot of people using a board in between the Flip and GPS. Do I need a Navi-Ctrl board like this one?

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The GPS I have is the RTFQ Mini uBlox 6M GPS W/ (35x35mm) Mounting backplane and Compass.

 

[jhitesma]

Forgot, the flip is a '328 chip. So yeah. You'll need an in between board because the '328 doesn't have enough power by itself to run a GPS. Really the '328 based boards aren't good options for GPS flight at all since they're so limited on memory and processor power. That setup may use I2C between the intermediate board and the FC...I'm not sure all I know is the guy who was wiring the firmware for those boards abandoned it and declared the '328 boards dead for GPS support. I've only use '328 setups on LOS acro quads all my bigger stuff has used the 2560 based mega boards or Naze32 boards.

 

[Pascal]

I've tried to use GPS serial configuration too... still doesn't work. I had few hope but I wanted to give it a try that way. I'll give it a try thru i2c or will keep my gps for my APM when it arrive.

 

[jhitesma]

Dealing with GPS on the '328 is just really ugly. Aside from the lack of memory and processor power there's not much in the way of serial I/O so you can't have the FC hooked to the computer for debugging and the GPS at the same time.

I2C from the GPS would solve the connectivity issue, but the I2C from the GPS isn't very helpful for a number of technical reasons so what happened was these interface boards that take the serial signal from the GPS and then convert it to I2C in a format that MW can handle. But support for that is being dropped in future versions of MW as it just takes too much space, isn't being maintained, and is an all around ugly fix for underpowered hardware. Funny enough it's being dropped to make room for more advanced GPS functionality which was written by the same developer.

So debugging GPS on a Flip 1.5 is tricky. Usually when you run a GPS right off the FC the FC configures the GPS for you. I'm not sure if that's the case with the interface board, it may be, it may not be. It may try to but be out of date. But it's something to look at.

 

[adamlepp]

I think I'll just grab a different FC and keep the flip on the shelf for now. Thanks once again jhitesma for your help!

Adam

 

[Litneon]

Does anyone know a good write up on how to make the GPS work at all with the Flip 1.5? I've tried everything I can think of, except re flashing the firmware on the Navi-control board (serial to i2c converter) or the uBlox.

I realize it won't be that good, but being new to the whole programming thing, now I just want to figure out why I can't get it to work.

I believe I have it wired correctly, and that it's down to either my settings in the sketch, or firmware issues in the other components. I have it wired per Paul's recommendations, and the Navi-control and 6M uBlox were supposedly pre-programmed.

Any help would be awesome, as I'd like to play with it while I try to figure out what FC to replace it with.