Yellow blinking light when transmitter's on

[I also posted a comment on this problem on the 3DR support page ([url][/url]), but I’m not sure if that’s the correct site or this one. Two different support sites?]

I flew my Iris successfully last weekend, and I tried to do so again today, but when I follow the startup procedure, I get the yellow blinking error code (yellow/yellow/blank/yellow). I brought it back home, turned it on without the transmitter, immediately got the blinking blue and then blinking green light, indicating it got GPS connection. Excited, I went back out to the field, got the yellow code again.

After coming home again, I realized the yellow code only comes on when I have the transmitter turned on. If it’s off, the IRIS arms fine. The transmitter has fresh batteries and is using the same settings as last weekend when it was working. Nothing’s changed except that I recharged the LIPO batteries. What’s going on?

So, I consult the LED list on the Flight Checklist. For this light pattern, it says, “System error: see troubleshooting guide.” Okay, where’s the troubleshooting guide? Maybe it’s in the Operation Manual? Page 15 says, “Error, disconnect battery and restart flight procedure.” Did that - no dice, still have the problem. Then it says, "See the troubleshooting guide at"

Sigh. Okay, I go to that website but find nothing that says anything about troubleshooting. I see links to PDF versions of the two user guides I already consulted, beginner video tutorials (which, incidentally, direct you to the /info web page for troubleshooting info), plus info on setting up the Tarot gimbal, Mission Planner software, APM Planner ground station, a maintenance section devoted entirely to hardware (how to open the shell, replace legs, arms, motors, etc.), and finally, a mysterious section called Tones which just has .wav files of Iris tone. Nothing appears to have troubleshooting info that I can see.

So, I’m stumped. Please tell me - where does one go find the bloody troubleshooting information?? If it’s on another page or site, it ought to have a link on the /info page. If it’s hidden somewhere in/on the /info page, it should be more prominent.

Argh. I’m grumpy because this flying day’s shot… my only chance this weekend. :frowning:

I had a similar issue and I too wasted a day trying to figure it out, even swapping out radio gear in my 2 day old iris. What I found was that the iris was failing prearm checks for high HDOP, if you connect your iris to mission planner, it will display the pre-arm check failure messages on the artificial horizon.

hope this helps.

I had same problem during initial bench test after I hooked it to APM planner. Steady flashing yellow if xmitter was on. Also noticed APM planner voice kept saying “RC calibration failed” as well as a text message in the HUD.

I took the battery out, hooked up the computer and performed the transmitter calibration for all channels and it hasn’t happened since. I have done Preflight at least 10 times to verify.

Btw - I’m using APM Planner for MAC instead of Mission Planner. Don’t know if the error and diagnostic messages are,different.


Have you had any issues pulling logs from your IRIS using APM on your mac? I cannot seem to get the logs to come up and would appreciate any tips you may have.



today I flew the IRIS for the first time and I switched to Win Mission Planner cuz it lets me replay the tlogs( telemetry logs). Couldn’t find a way to do that in AMP MAC. The Win version has more features right now or I haven’t found them in APM 2.0.

Running a win8 session in Parallels on MBA 2013.

I use a bluetooth earpiece on BT to my MBA to hear the verbal messages from APM while the computer is in the back of the jeep. I use gorilla tape to the mount the telemetry antennae to the top of the jeep.


I use the terminal to pull the logs. Haven’t had an issue with either version of the Mission Planner or APM.


[quote=“knightrider”]I had a similar issue and I too wasted a day trying to figure it out, even swapping out radio gear in my 2 day old iris. What I found was that the iris was failing prearm checks for high HDOP, if you connect your iris to mission planner, it will display the pre-arm check failure messages on the artificial horizon.

hope this helps.[/quote]
Knightrider, thanks indeed for that info. I checked it out in Mission Planner, and arming it showed that I was also getting a high HDOP warning that prevented arming. Indeed, the HDOP is well over 2.0. In most cases, I wasn’t getting contact more than 5 or 6 satellites. Which is weird because the whole thing was working just fine last week in the same wide-open park. The only difference was that it was overcast this weekend. Is the GPS receiver in the IRIS is so weak that cloud cover blocks GPS satellite signals? Also, switching the transmitter to non-GPS-reliant modes didn’t help, so that’s a mystery, since theoretically, you don’t even need a GPS connection for those, but it still wouldn’t arm.

If I’m only able to use this thing on clear, cloudless days, that’s going to suck. Because we don’t get many of those in my part of the word.

Hi All,
I am convinced that the GPS antenna being inside the shell is too close to other (un)intentional RF emitters, while mod 7 from in my signals fratricide posting) is going on my IRIS today and I will report back as to the success or failure. if failure I will be sticking a simple coax pin probe from my RTL/SDR and seeing the amount of interference on the L1 GPS frequency is found(which wont tell me about leakage into the GPS circuit at other rf frequencies or how the ublox handles same.) in any case I will be shielding the bottom of the GPS install with a grounded but surface insulated copper ground plane from copper embossing foil. And wrapping all cables in light weight foil strips or coax braid if the mod7 recommendations dont result in a low enough HDOP if that doesnt work fabricating/printing a folding GPS mast and affixing it to the hull to gain some distance from the interference.


Thanks for the info, HZL. That’s disappointing to hear about the GPS interference issues you found. I would’ve thought they’d have done tests for this sort of thing early on. Shielding seems pretty basic.
Maybe we’re in the minority, though? Not many others seem have this problem. Maybe we got bum equipment?
I’d hate to go through the hassle of sending back for servicing, having just gotten it. But if I can’t fly it, it’s not doing me much good. :angry:

I have been setting the prearm check to 3.5 to bypass my high HDOP for arming and then taking off in stabilize mode and flying manually until the telemetry indicates a useable HDOP and then switching to automode.

   somehow this does not seem right when my android device and iphone are both indicating a high resolution fix.(3rd party sensor suite for iphone) I should note I am getting a 10 meter fix via gps on my current location with a floor above and a roof overhead on the iphone.(wifi is off)..

The android tablet/ iphone can see 9 freaking satellites in the freaking basement and has a twelve meter /10 meter fix and the IRIS has problem with a CAVU sky in the middle of an open park with no trees closer than 200 yards?? WTF???

            I am starting to have real thoughts about the GPS being defective or being incorrectly implemented.

             HZL(whos is noticing all of these things with a barely flown IRIS)

ps Its unusable this way… its also dangerous to attempt to fly in GPS modes this way.
I am also NOT a hobby user as this machine was purchased to develop applications involving drones on so I have been studying this problem since it(the IRIS) arrived I just didnt see it as a problem till now, the IRIS has been here 1 week and its not quite the smooth experience its advertised to be… I can see it getting a whole lot better AFTER the GPS issues are solved however… emailing support…

Wow, yeah that does sound defective. Let us know what they say or have you try. I get mine tomorrow. I sure hope my uBlox GPS module is sound, as I will be depending on that quite extensively!

ok I just spoke with Fes at 3dr tech support… and awaiting a tracking number for a new GPS unit(hopefully not defective this time) and a new bulkhead micro USB connector…

  we will see how this goes.. told him this malfunction was a bit too public(middle of a park with 4 other pilots very cautious of the IRS failure to get a gps lock..) the bit about the cell phone and tablet obtaining hard fixes a bit much(in a basement no less while the iris sits under a blue sky...)


ps a LOT of the problems folks are having in these forums directly traceable to bad GPS performance, key is getting the telemetry talking to a ground station first thing so it can be identified…wow just got the tracking numbers for the GPS and Micro USB connectr 10 min after complaining to latest tech… Fes came through… we will see how it acts with the new GPS…after it gets here… I will stop complaining till then…

pss the ENTIRE IRIS is very dependent on accurate GPS without that the IRIS is just another flying black pig of a quad. With GPS its a thing of wonder…

Bummer, glad they are taking care of you though… Keep us updated!

Guess I’ll contact support again myself. Sounds like I have the same bad GPS problem you have, HZL. Bummer - one thing after another! Was looking forward to actually flying this thing again…

FYI - My IRIS has been in the air about 12 times and I have never had GPS issues. 8 to 10 sats every time. Loiter works every time.


3DR has sent me a replacement GPS, I am now getting an HDOP of 2 INSIDE under a wood roof with 12 satellites… time to retire the other GPS unit and send back to 3DR(or give to chrisA personally at the flyday friday in berkeley).
And additionally I have a 600mw 5ghz velcroed with attena positioned away from the GPS part of the hutt(awaiting a RP-SMA 6" pigtail to put attenae on leg and move sheilded VTX inside hull,
Thinking about vacumn molding a larger extended clone hull from clear lexan or clear HIPS/kydex) after making silicon negative and clay positive of present IRIS hull bottom and top and then converting to a point cloud/mesh/nurbs for redesign…dont know if laser scan of sufficient res to capture the screw holes accurately enough …)

So in my case at least it was a defective(for whatever reason) GPS unit…

   Thanx 3DR Customer support(Fez is to be commended)

ps didnt need the copper ground plane anymore

well i may need to call them as well, for the first flight of the day i have to set my iris outside for about 10 mins before the yellow light will turn green. while my nexus 7 tablet has 9/9 sats with a HDOP of 1.1, my iris, sitting right next to it has 9 sats, HDOP of 2.5.

i wish the iris had the same gps chip as my HTC one, its sitting here with a 15/24 sats with a HDOP of .7 :cry:


Did replacement uBlox GPS units cure the high HDOP problems you were seeing on the IRIS? I have been unable to launch with standard prearm check because of this issue on multiple days over the last month.


I never replaced my GPS, I seems to get decent HDOP after the iris sits for awhile outside, or I will plug it into the USB and let it sit by the window before I go flying so the GPS has a good warm start and gets a quick fix

Sent from my HTC One using Tapatalk

All GPS units are tested before they leave the factory. If you have noise on the GPS, it most likely really is there. It is a good idea to use a solar radiation monitor like or and some of the planners have it built in.

It is a really bad idea to turn up the maximum permissible HDOP. i.e. Fix the problem don’t just cover it up.

One of the issues I have seen with some of the vehicles that have the FS Sky Receiver in them (i.e. Iris) is that in some cases the RC receiver creates interference with the GPS. Open the Iris shell and have a look. If the RC antenna is wrapped around the GPS receiver, I suggest moving it away from the receiver.

it only needs to move a few cm to make a big difference.