This little guy is great, but today it wouldn't fly until IMU calibration is accomplished.
It has taken two batteries, and still not updated.....doesn't seem right.....can't take off until completed.....any ideas?

I had some issues with IMU Calibration a few weeks ago.  One recommendation from Elektra was to take it outside.

This was my post and thread      https://forum.dji.com/thread-133579-1-1.html

After numerous attempts, it finally calibrated and I haven't had any issues since.

Thanks for the quick response......depleted two batteries outside, now working third battery at window, still stuck on second page.........dave

When mine was new i had the same as it got stuck on step 2.  Dji helped much and did all that they said to do and all was good but do not know what the cause was but have no trouble now. I will say the first time was because i did not have glasses on and just rotated it and not put on side... DUHH. but did try the right way and still failed until reinstalling all and starting over.

nmac Posted at 2018-2-27 13:08
When mine was new i had the same as it got stuck on step 2.  Dji helped much and did all that they said to do and all was good but do not know what the cause was but have no trouble now. I will say the first time was because i did not have glasses on and just rotated it and not put on side... DUHH. but did try the right way and still failed until reinstalling all and starting over.

Thanks for the tip.....when you mention tipping on it's side, you're referring I think to the compass, which requires moving around to calibrate. The IMU update remains stationary, no movement......but should only take 30 secs...........well, I'll try again tomorrow........TUVM.......dave

Rustic17 Posted at 2018-2-27 12:06
After numerous attempts, it finally calibrated and I haven't had any issues since.

Roger that, I'll reload and try again....TU.......dave

Do a factory reset and then try to see if it works

fans0e88a218 Posted at 2018-2-27 13:35
Thanks for the tip.....when you mention tipping on it's side, you're referring I think to the compass, which requires moving around to calibrate. The IMU update remains stationary, no movement......but should only take 30 secs...........well, I'll try again tomorrow........TUVM.......dave

No, that's wrong, here's how it works.

Compass calibration: You will be directed to rotate the aircraft 360 degrees in two directions and that's it, it only takes about 20 seconds.

IMU calibration: You have to put the aircraft on its feet, then on its sides, on its front and on its back and finally upside down, and let it sit for about 5-10 seconds every time, until you are prompted to go the next step. The lights will also be flashing to indicate that the next position is up. The whole process will take a few minutes (less than 5). However, if you just let it sit and don't move it according to the directions on the screen, it will wait for the next position until the battery's empty...

Here is a video I made a while back about the IMU calibration.  A lot of people don't notice the change in direction and think its stuck...

Nice work!

Got it!!.....thanks to all for your great help. After bringing the tablet out of the direct sunshine, I could read the prompts properly.
Special props to Kloo Gee for the fine tutorial.
Also, I left the propellers on and the guards in place and hand-held the unit in place, following the prompts.....worked just fine.........dave

Good but imu is not compass cal. both different. but will say i now see just like me you did the same as me and not standing on side on step two. but i did have another issue that dji helped me. but must tell you that to do proper take all off of it as the props can interfere and give a bad reading. And to Kloo Gee thank you for your videos to help me learn and now more about this little guy. but.....................   please take all off and redo as i feel something would not be right as you did not do right.  Yes ask me how i know.
have fun and be safe.

KurtVD Posted at 2018-2-27 13:57
No, that's wrong, here's how it works.

Compass calibration: You will be directed to rotate the aircraft 360 degrees in two directions and that's it, it only takes about 20 seconds.

spot on guy spot on.. as my first attempt but had other issues with mine but now all is good. and will say very good info that i should have said.

I think the compass calibration is just showing the Spark's AI the range of electrical values it will get from the compass unit for all three hundred and sixty degrees of rotation.  It is not really a north south east or west thing.  

I think the IMU calibration is just showing the Spark's AI the range of electrical values it will get from the IMU unit for an one gee force forward acceleration (on it's rear legs) , a one gee force side acceleration (on it's side), and a one gee force vertical acceleration (upside down).  After all, we know exactly how much the earth sucks.  

Since every sensor unit has slight manufacturing variances on output, this gives the Spark unit values for known conditions.

I have never done a IMU calibration (had issues and quit trying) and have only once done a compass calibration.  And I have never used RTH.

Gunship9 Posted at 2018-2-27 17:58
I think the compass calibration is just showing the Spark's AI the range of electrical values it will get from the compass unit for all three hundred and sixty degrees of rotation.  It is not really a north south east or west thing.  

I think the IMU calibration is just showing the Spark's AI the range of electrical values it will get from the IMU unit for an one gee force forward acceleration (on it's rear legs) , a one gee force side acceleration (on it's side), and a one gee force vertical acceleration (upside down).  After all, we know exactly how much the earth sucks.  

from what i have seen and read if the imu was done wrong as on un level ground it would tilt thinking is flying level but not and move on its own.

I did the same thing today spent a bunch of time on step2 at 90% then realized the pic was showing the spark on its side. Did the whole cartwheel thing on all sides and it's good. Did the Compass as well after. Actually went through all the options and settings and tweaked a few things I never saw before.

Kloo Gee Posted at 2018-2-27 14:33
Here is a video I made a while back about the IMU calibration.  A lot of people don't notice the change in direction and think its stuck...

https://youtu.be/wYCK6HXwLTs

Thanks for your hard work. The video has a specific explanation about IMU. It is really helpful.

fans0e88a218 Posted at 2018-2-27 16:24
Got it!!.....thanks to all for your great help. After bringing the tablet out of the direct sunshine, I could read the prompts properly.
Special props to Kloo Gee for the fine tutorial.
Also, I left the propellers on and the guards in place and hand-held the unit in place, following the prompts.....worked just fine.........dave

Glad you solve the problem. Have fun with your spark.

nmac Posted at 2018-2-27 16:37
Good but imu is not compass cal. both different. but will say i now see just like me you did the same as me and not standing on side on step two. but i did have another issue that dji helped me. but must tell you that to do proper take all off of it as the props can interfere and give a bad reading. And to Kloo Gee thank you for your videos to help me learn and now more about this little guy. but.....................   please take all off and redo as i feel something would not be right as you did not do right.  Yes ask me how i know.
have fun and be safe.

True, I don't think it can be done right if the prop guards are still on, I'd definitely do it again without the guards. However, I don't see the need to remove the propellers (even though DJI says so): it's possible to position them in a way that they don't interfere with the procedure at all.