I'll put this on YouTube shortly, but I just rummaged in my kit and found a USB A to C adapter lead.  I connected my Zoom H1N to the adapter lead and when I turned on the recorder, it recognised the Action 2 as a destination device.  It asked if I wanted PC/Mac mode or iOS mode, and I chose the former.  And a mic level symbol appeared on the Action 2.  So I made a 30 second test recording which left no doubt that it works, by setting the Zoom input level to zero and talking, then raising it to 7 and talking, and also whispering right into the Zoom's mics.  It works!  This means that the Zoom can be used an audio interface to the Action 2, because you can connect whatever you want to the Zoom's input and that will be passed to the Action 2 instead of the Zoom's internal mics.  The big question is.... what is the adapter lead?  Is it an OTG lead?  It's completely unmarked so I simply don't know.  I'll try to think of a way to check that out.  I do have an OTG USB hub device and it will be interesting to see whether that works too.

Anyway, bottom line is that the USB socket on the Action 2 can indeed be used for audio - if you connect the right thing to it.

OF course the Zoom H1N is rather larger than the Action 2.. I have a smaller Zoom F1 recorder which almost certainly would work.  That could be clipped to a belt or pocket with a lav mic connected, or Roland binaural in-ear mics, and connected to the Action 2 quite neatly.

Oooo, fun!


More to come....

Update - I have now found a little adapter plug from USB A to USB C and that works fine instead of the mystery lead.  It's branded Aukey.  So it seems that OTG type lead isn't required.  My only concern with using that one-piece adapter is that it might be imposing a bit of a mechanical stress on the Action 2 USB port, so I'd be more inclined to use the flexible adapter lead.  Ideally I will find a direct micro USB to USB C lead and avoid using the adapter at all.

This is really badly produced, but here's a quick and dirty video showing the H1N connected to the Action 2, as proof of concept.

Further update - I have successfully tested the Zoom F1 with the Action 2.  The F1 has the advantage that it is about the same size as the Action 2, so they don't look silly if mounted together.

Also, I note that when there's an external audio stream detected, the audio options menu on the Action 2 changes to show a means for setting the audio level, which is handy.  Audio is metered using a tiny but perfectly adequate icon on the screen.  This goes red in the presence of an overload.

Hello there Peter. Good day and thank you for sharing these information and this video with us here at DJI Forum. Again, thank you for your support and keep filming.

Thanks for sharing.

Thanks for sharing!
I have a H1, so that should work.

I also confirm that the above way works with the external audio recorder TASCAM DR-05X. Τhe result is incredible, putting the sound limit where I want it to be.
Thank @fansfe82067d for sharing!!!