*** Note this Blog post was done a long time ago, this is no longer needed with the latest Solo updates. Current Solo firmware will trigger the GoPro during an auto mission correctly, and the cam trigger messages on the data flash logs can be used for geotagging the images via mission planner or directly in software like Pix4D ***

There have been a lot of questions about how to this in several forums, I posted a solution a while ago on the Facebook Solo Mod Club page, but with all the demand I think I should also post it here. 

First understand that this is a hack that modifies some files inside the Solo and that you may or may not need to do a factory reset before you upgrade to the next version of the firmware which seems it will contain something similar to this modification. So do this at your own risk and only if you know what you are doing. 

From the comments bellow, I think this explains it better:

"With the current Solo update system, user modified files will not be updated during a software update. To get the update, either a patched version of the new file will need to be manually installed (taken from a "clean" updated copter) or a "factory/settings reset" needs performed to get the copter back into a clean state before updating.

As with any software mods, it's always best to back-up the original file before modifying it (use something like "cp"). The backup can then be restored before a software update and then the updated file can be patched/modded again." -- Angus Peart

The Pixhawk firmware in Solo already has everything that is needed to trigger the GoPro for survey missions. It has the logic to trigger the GoPro based on distance or by using a explicit trigger waypoint. What is missing is for the companion computer inside Solo to interpret this messages and send a command to the GoPro to take a picture. This is what my mod does. Also it creates a log file for each flight where it stores the positions of any still pictures you take with the GoPro, not just during surveys, but anytime you trigger a still. 

Here are the steps:

1. Connect your computer to the Sololink WiFi network

2. Use an FTP Client to connect to Solo (root:TjSDBkAu@

3. Make a backup of /usr/bin/

4. Replace /usr/bin/ with this file:

5. Reboot you Solo

From now on whenever the Pixhawk sends a trigger command the Solo will trigger the GoPro and take a still. If the GoPro is in video mode it will switch it to still, take a pic and then put it back to video. Please note that everytime the GoPro takes a still you will loose video or see artifacts on the video. This is normal, and is related to how the GoPro works. If you fly too fast the GoPro may not respond to the trigger commands fast enough. Also if it has to switch between video and still it will take longer to take a picture and you may miss pics. So set the camera to still mode before starting the flight.

Once you have finished your flight you can use FTP to pull the georef log file from the solo. You should find them in /log/geoRefxx.log where xx is the number for the log and is incremented each flight. Have fun mapping with Solo.

PS. The picture above uses something similar but with the QX1 Edison Camera trigger on an earlier article I wrote. Since Solo is Pixhawk based you can use that too.

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  • Hi Rick,

    The current release has fixed the issue, so no need to manually update file.  I had to do a factory reset to mine to get it to work on the latest version.


  • For current developments on this, follow this thread. Franknitty69 has a fix that works for me. Perhaps Jaime is working mainly through the developers page on Facebook now, but I am not in that.

  • is this still the preferred method, and is there a tutorial showing the proper steps involved? 

  • Developer

    I'll have to check the code again, but I think if you setup the cam-trigger-distance it should still trigger the camera, and the pixhawk will log the messages. Let me dig into it.

  • There still is a need for this type of mode.
    Or something like it.  The 3DR code only works in Auto mode.  I have some jobs coming up - mapping buildings. There are trees and all sorts of things in the way. 

    I was planning on setting the cam-triger-distance and flying it in loiter. So looks like I might need to mode code anyway. 

  • that would be awesome, the sony qx10 in conjonction with sony play memories software for win has some excellent latency (140ms)3702185622?profile=original

  • Developer

    I'm working on it (tutorial), its not 100% yet. So there is no point on releasing one yet (will create to many support questions). We are also working on companion computer images that will make things easier to implement.

  • this is Jaime code:

    I am not so good at coding, would be happy if someone would do a tutorial


  • Hi Jaime

    would you please explain about yellow SOLO. how it triggers sony QX1 ?

    thank you

  • Developer

    Hi all, the post has been updated. The current Solo code already triggers the GoPro so this mod is not necessary anymore. You can use the data flash log's CAM messages to geotag the GoPro images using mission planner. Use this process:

    As of the Solo 2.0 release, the dataflash logs are located on Solo at /log/dataflash . They are automatically copied from the pixhawk to the Solo iMX companion computer. Use sFTP to to get the logs (user root, pw TjSDBkAu)

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