Hey I live in Bangladesh. My problem in my APM 2.5 the GPS is not locking. The blue LED of APM is solid and it shows 3D fix on mission planner. But the Blue LED of GPS is always blinking. Even if I kept it outside for about half an hour the GPS doesn’t locked. What should I do? What will apppear in the mission planner if the GPS is locked properly? please help
Hi, Could you give me some more details on what GPS module you are using?
Could you also share a screenshot of the mission planner when it says 3D fix on the HUD? Once the GPS has a lock you should see the 3D fix message in the corner of the HUD on the mission planner, and on the map (right side) you should see the location of your quad.
yes the 3D fix message is shown on the HUD. But the blue LED of the GPS still blink. I don’t know why. And another thing I couldn’t ARm it in loiter mode. I think thats bcoz the GPS is blinking… or is there anything else? Please reply… thanks in advance…
That is very strange indeed. I have a couple questions/suggestions.
What GPS module are you using?
When it shows GPS long in the mission planner can you see the correct position on the map in the mission planner?
Also does your GPS module have a clear view of the sky?
Finally you might need to reconfigure your GPS module (depending on what module you have I could help you further)
Hey thanks for replying… I’m using the older version of 3DR Ublox LEA-6H Module. I mean this module(see link) but without the compass,
https://store.3drobotics.com/products/3dr-gps-ublox-with-compass
Yes it shows my position correctly but the quad on the mission planner still has some deflection. Sometimes it shows home on the mission planner but the Blue LED of the GPS keep blinking. Yes My GPS has a clear view of the sky. But as I’m doing it in the roof top there are some other houses beside me. Can this be a problem?
How I could configure my GPS module? please tell. And is there any other GPS module better than the ublox to use with APM 2.5? please give me the link if any unit is available to work with APM. Here is the picture of my GPS module 
There are two methods to update the configuration on your ublox.
Option 1, using an FTDI cable
You will need an FTDI cable and a GPS adapter cable to connect the GPS to your computer. If you have never plugged an FTDI device into your computer, you may need to download and install the FTDI COM port driver.
Option 2 using APM as a passthrough
This lets you use your APM board as a bridge to configure your Ublox GPS module, its nice as you dont need any extra cables, but you will need to load the special Ublox pass through firmware
A video on how to configure the Ublox device is shown below
