Replies to This Discussion

3D RoboticsPermalink Reply by Chris Anderson on June 28, 2011 at 7:55am

Are you sure the GPS is plugged into the right port?

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Permalink Reply by Justin on June 28, 2011 at 8:04am

Hi Chris, yep, quadruple checked that the leads were plugged into the board and not the shield.  Also tried pressing the reset button after the GPS light stayed solid...  all to no avail.

 

Getting quite desperate and will try anything!  thanks!

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3D RoboticsPermalink Reply by Chris Anderson on June 28, 2011 at 8:32am

Check the little pins in the APM GPS connector. Maybe you've bent one?

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Permalink Reply by Justin on June 28, 2011 at 9:17am

Hi Chris,  thanks for trying. 

 

I took a flashlight to both connectors and all 6 pins on each side look to be straight and in order. 

 

Is there anything else you can think of for me to try?  Thanks!

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3D RoboticsPermalink Reply by Chris Anderson on June 28, 2011 at 9:32am

Check the cable for a loose/broken wire? Something broke when you moved your setup; you just have to figure out what.

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Permalink Reply by Justin on June 28, 2011 at 9:46am

Hi Chris, checked both ends of the cable but it looks intact - when making the move, I disconnected the GPS to avoid any strain on the cable.

 

Do you think it would help to try a replacement cable?  If that doesn't work, what would you recommend? something along the lines of 1. change the connector on the APM and then 2. swap out the GPS unit in that order?

 

Two things are a little baffling to me - first why does the HK GCS show a 3D GPS lock with no satellites and second, I'm showing the 1970 UTC time in HK GCs.  I would have thought that with no GPS attached, neither of these should be showing.

 

Thanks.

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Permalink Reply by Justin on June 28, 2011 at 11:43pm

Hi Chris,  Just had a thought - since the problem appears to be the hookup between the board and the GPS, can I solder 4 pins into the holes on the board just behind the GPS connector (marked ground, v+, In and Out) and then connect them to the corresponding 4  pins on the GPS module?

 

If that works then I will know for sure the problem lies int he cable/connector.

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3D RoboticsPermalink Reply by Chris Anderson on June 29, 2011 at 7:51am

Yes

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Permalink Reply by Justin on June 29, 2011 at 8:43am

Thanks Chris.  Just tried it through the I2C port and then I soldered the 4 pin header in the tried it directly.  Both connections yielded identical results.

 

Something different today - there was an * after the first G in the GPS terminal test.

 

Do I need to have GPS lock for things to work?  I was outside yesterday during testing but tried everything indoors today with no GPS lock.

 

So it seems the cable/connectors are not the problem?  Is there anything else you can think of for me to try?

 

Thanks.

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3D RoboticsPermalink Reply by Chris Anderson on June 29, 2011 at 9:32am

Yes, it will not work without GPS lock.

If you load the APM code (just pick the plane in the Mission Planner firmware upload screen) there is a "raw gps" test you can run from the CLI that will show you exactly what your GPS module is outputting.

http://code.google.com/p/ardupilot-mega/wiki/Test