Hi: I am driving myself crazy (not a long trip) trying to get my Action set up for a timelapse of a meteor shower...I make one adjustment and then I am locked out of making any others...The camera just is not doing what i think I am setting...I want it to  take a 20 second exposure at ISO 1600, pause 2 seconds, take another 20 second exposure, etc...Duration of about 3 hours...(I can't stay awake later than that!)...Can someone provide step by step instructions that will get me going with this? It would be much appreciated!

are you after a  nightlapse like gopro

Unfortunately what you want is impossible with Osmo Action. There are only certain, fixed combinations of interval & exposure times available.  At 20 seconds exposure time, the only interval you can use is 30 seconds (which includes the exposure time) and it will give you 20 seconds of exposure and 10 seconds of pause in between the shots. If you go down to 10 second exposure time, you can select 13 seconds as an interval (among others), giving you 10 seconds exposure + 3 seconds in between shots.

The instructions are very simple: Since exposure time is the priority in your case, set that one first. Then when you go into your interval settings, the camera will show you only the available ones for your set exposure time. Hopefully you will find what you need there; and if not, there is nothing else that can be done...

Hope this helps,