My first post here, so I hope I haven’t put it in the wrong place. Got my IRIS+ yesterday. Charged up the battery while assembling the gimble, tall legs, etc. First flight, no tweaking, adjusting, or calibrating! This is right out of the box! I like it! Haven’t linked to my tablet “yet”. With all the trees in my home area, I’m rather afraid to go autonomous. Will wait till I go to an open field first. Question? Once a flight plan is uploaded to the IRIS+, in auto mode, it’s flying off of GPS right? So if I upload a flight plan, say up and down my street, will the trees effect it, if it’s above all of them?https://www.youtube.com/watch?v=zqEdXxOjDjQ
Nope, The satellites are in space and when the signal goes through the trees it is distorted and can cause position errors. Once your above the trees, clear line of sight to the satellites, The signal should be good.
It may take a little time for it to lock in once it gets above the trees. This is where a tablet or GCS comes in. It can tell you what your HDOP is which is an indication of how well the GPS position is doing.
I often take off before GPS is good and wait for it to get high in the sky before switching to Position Hold or Loiter.
Starting a mission for the first few times is very scary and would not recommend that as a first mission.
Mike
Thanks Mike. Being a nube to the Iris+, of course I have several questions. Been doing a lot of reading, but my old head will only retain just so much. How do you arm your Iris+ “before” it has GPS lock? Also would like to know how to calibrate the compass, without having to use mission planner, and the attached cable? Did my second flight yesterday, and I could not get it to arm. Linked to my tablet, and got the voice alert that the compass was out of sync. So I had to bring it inside my mobile home, hook up to my desktop, and do the compass calibrate thing. Got it good enough to arm, but I know it should be done outside, away from metal, etc. etc. I do love this machine though! 
Sorry for the delay here, missed this one.
You can take off without a GPS lock but I usually wait for it to at least flash green. If you stick with STD which is ALT Hold mode to the controller it should be fine in that it does not rely on the GPS just the Barometer for height.
When you take off the copter records this position has Home. So if the battery failsafe is reached to knows where to fly back to. Also if you have and I think it is a default on IRIS+ is that geo fencing is turned on so it will not let you arm and fly without a good GPS fix. This is so it knows when you reach the fence and it should either stop or come home.
Mike
Thanks Mike. I’m still learning. Yesterday, I hooked up to Mission Planner, and shut off all the failsafe’s. Problem I have is at home, I’m under a huge tree canopy. My Iris+ will still lock on GPS in just a few seconds, even under the trees. However, I do not want it to ever try to return to home, at least while I’m playing around at home, because it would come down, crashing into the trees. I managed to try to calibrate the compass’s, but it is a pain with the wire hooked up to the Iris, and trying to go through all the different positions. How do you do it without the wire attached? I did my second flight yesterday. Just straight up, into “loiter”, and a couple of slow pans, with camera at different angles. I’ve used the “channel 7 LAND” switch twice, and she sits down, nice and easy, all by herself. Can’t wait to go to an open field, and try some auto stuff, fingers crossed! Gotta look up a lipo for the FlySky radio, instead of the supplied dry cells. Having a blast. The rest of my fleet is growing dust! 
I did my compass calibration connected to MP wirelessly. It worked fine. Also a trick I found was to use a swivel chair for all positions to rotate 360deg. Found it on youtube.
Nice to hear.
With all the conversions going on it’s getting hard to remember who I was talking to and what there issues where.
Mike
Yes, there is a whole lot, to this Pixhawk. Eyes tired from all the reading. Quick question, is there a way to extend the time allowed for compass calibration? I can’t get as much done, as I’d like, before it stops and saves. Also, the way I understand it so far, the only way to calibrate the compasses (2) is through “Mission Planner” right? The calibrate on droid planner on my tablet, only seems to calibrate the gyro’s. “LOT’s” to learn for sure, but I’m having fun. Kinda like driving on the autobahn, “no limits”
This is the one that has changed over time. Not sure how it works now. Is this the one with the sphere and you need to paint all the dots on it.
I thought there was a button to tell it when your done.
I only use Mission Planner, have not tried to do it with the tablet.
Mike
I did the compass calibration just recently and it was different than the videos I saw where you fill in a sphere for as long as you like… Once the calibration was satisfied with all 6 sides top, bottom, left, right, front, back 360 degrees it stopped. Don’t know how to change it, but my calibration was fine this way.
OK, took my Iris+ into the yard, away from all metal, etc. etc. connected to my laptop via mavlink (wireless), and ran both the gyro and compass calibrations with mission planner. There are 2 little check boxes at the bottom. One stops the globes (2) from rotating, to make it easier to fill in the blank spots, and the check box next to that will stop it from running “until” you click the “done” button. The Iris+ has 2 compasses, 2 globes appear. 
sorry, I meant the second box will keep it running, until you click done. Where’s the edit button? 