ublox m8n can't connect Revo
« on: March 26, 2018, 03:56:48 pm »
Hi all!
I've just posted my first here:

I can't connect my gps to Revo. I wired it on the flexi port because in the magnetometer configuration page didn't find main port.
System health input is red, ATTI is red and gps has a red cross on.
Attitude calibration ask my position

Can you help me?

Thank you in advance.


Re: ublox m8n can't connect Revo
« Reply #1 on: March 26, 2018, 05:44:20 pm »
GPS "red X" means that it cannot talk to GPS at all.  First, understand that plugging Revo in to USB does not power the GPS.  You must have flight battery plugged in to ESC/BEC to make 5V for Revo for power to go to MainPort / FlexiPort.

FYI: GPS "red block" (not red X) means "good but GPS has not got position lock yet".  Yellow means it has a position lock but not good enough to fly.  Green means GPS ready to fly.

If not simple power issue, it could be wrong cable.  For serial function, the cable must be made with Tx and Rx "crossed".  "FC (Flight Controller = Revo) Tx must connect to GPS Rx" and "FC Rx must connect to GPS Tx".  If this is your problem, you can use #11 model knife blade to very carefully only slightly lift the tiny tiny plastic flap on the cable for these pins.  Slide Tx and Rx pins out and slide them back in in reverse order, Rx and Tx.

I saw your other post, but I had to use Google to translate.  If MainPort is not working, look in the FC MainPort connector to make sure that the pins are straight.  #11 model blade will get the straightening started, but then you need a super thin needle nose pilers or maybe hemostat to squeeze the pin straight.  Be very gentle if what you use has teeth to make sure the teeth don't make marks in the pin.
« Last Edit: March 26, 2018, 06:05:01 pm by TheOtherCliff »

Re: ublox m8n can't connect Revo
« Reply #2 on: March 30, 2018, 12:33:41 pm »
Thank you for your reply and sorry for my late.
I increased the speed (115200) of the port and gps block bacame red. Now is green. (8 satellites).

Thank you very much.

Re: ublox m8n can't connect Revo
« Reply #3 on: March 30, 2018, 07:22:35 pm »
It also works well at 57600.  If you didn't change anything else, then it sounds like you did not have flight battery plugged in before, and so the GPS did not have power.  This is a common issue that we have all done at one time or other.  :)

Re: ublox m8n can't connect Revo
« Reply #4 on: April 09, 2018, 09:28:18 am »
I can not connect as well How do I connect?

Re: ublox m8n can't connect Revo
« Reply #5 on: April 09, 2018, 05:24:36 pm »
Do you have a Ublox GPS?

You must have flight battery plugged in.

Look inside the tiny white connector on the FC to make sure all 4 pins are straight and uncrushed.

Does the GPS LED come on?  Does yours have a power LED?

For an OpenPilot Ublox GPS:  Look at the ordering of the wire colors on both ends of the GPS cable.  The last 2 wires must "cross" and be for example "blue orange" on one connector and "orange blue" on the other.  Very very carefully lift the tiny flaps on the connectors just a small amount (use #11 model knife blade) and slide pins 3 and 4 out of one connector and put them back in 4 and 3.

For a Pixhawk Ublox GPS: you must make a cable (cut the end off and solder the correct connector) with pins in the correct order.  The GPS Tx pin must connect to the FC Rx pin and the GPS Rx pin must connect to the FC Tx pin.

You also must have the Hardware page set so that port is GPS Ublox 57600.  After rebooting the FC, GPS should automatically work.  Go to Flight Data page and look at System Health.  [GPS] will be "red X" if something is bad wrong (no battery power, wrong cable, dead GPS, etc.).  Otherwise "red block" means it is working but no satellites so far.  "Yellow block" means some satellites but not a good amount.  "Green block" means good number of satellites.