Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

IMU Warning and slow warm up

Discussion in 'Pro/Adv Discussion' started by FASTFJR, Sep 10, 2015.

  1. FASTFJR

    Joined:
    Nov 7, 2013
    Messages:
    1,201
    Likes Received:
    169
    Location:
    South East PA
    Ever since the update on Monday I get an IMU warning. I've calibrated the IMU 3 times on a flat level surface. Each time I do it the numbers are perfect. Its take the P3 (pro) about 2-3 minutes for the warning to go away and "Warmed Up". What am I missing? what is the issue? Once its ready to fly its fine and will hold a spot perfect
     
  2. D4T_PoM

    Joined:
    Jul 28, 2015
    Messages:
    693
    Likes Received:
    183
    Location:
    London UK
    I believe in order to minimize warm up you have to calibrate the IMU when the P3 is cooled down.

    So wait a few hours when the P3 has cooled off do the IMU calibration again.

    I think i read somewhere some members put the P3 in a fridge (without battery) and let it cool off faster but personally I would just wait out and let it cool off on its own.
     
    eseckinger likes this.
  3. bbfpv

    Joined:
    Feb 3, 2015
    Messages:
    3,745
    Likes Received:
    1,092
    Location:
    Long Island, NY
    calibrate when the bird is cold. ie, put it in front of the AC for a few mins, then do the IMU calibration.
     
  4. FASTFJR

    Joined:
    Nov 7, 2013
    Messages:
    1,201
    Likes Received:
    169
    Location:
    South East PA
    Yea, I've done that. I calibrated in the house at 72F, maybe thats not cool enough. But what am I missing? Each time I have done the calibration its fine, numbers are fine. Can you go thru the calibration process and it passes but its really not OK? That seems to be happening to mine? This only started on Monday with the latest update. What I don't understand if the IMU Calibration says its off or incorrect than it should be. But after waiting 2-3 minutes the message goes away and it fly's just fine

    Thanks
     
  5. adrian.ahonk

    Joined:
    Jul 27, 2015
    Messages:
    97
    Likes Received:
    13
    I used to calibrate the IMU many times by cooled the bird in rereferige
     
  6. sonic260

    Joined:
    Sep 9, 2015
    Messages:
    1
    Likes Received:
    0
    bbfpv is correct, it really needs to be cold, take the battery out and put it in front of the AC for a while, I've even read people have put it in the refrigerator but I think that's a little overkill!
     
  7. adrian.ahonk

    Joined:
    Jul 27, 2015
    Messages:
    97
    Likes Received:
    13
    I used to calibrate the IMU many times by cooled the bird in refrigerator first
     
  8. bbfpv

    Joined:
    Feb 3, 2015
    Messages:
    3,745
    Likes Received:
    1,092
    Location:
    Long Island, NY
    Needs to be colder. Your warm up times should be in the seconds range, not mins. Cold IMU calibration allows the sensors to record a bigger range of data, which means it doesn't have to collect the data again each time the ambient temp changes when you start up outdoors. It works.
     
  9. bobmyers

    Joined:
    May 10, 2015
    Messages:
    3,611
    Likes Received:
    866
    Location:
    San Antonio, TX
    on 1.1.9 I calibrated at AC room temp 72 degrees and everything was fine-- when I upgraded to 1.3.2 -- I did the same thing-- so now mine takes about 2 minutes to warm up before flight. Getting ready to go to 1.4.0 -- I think I will do it "Cold" this time.
     
  10. FASTFJR

    Joined:
    Nov 7, 2013
    Messages:
    1,201
    Likes Received:
    169
    Location:
    South East PA
    OK, I get the part about being cool and I'll put it in the fridge. But why do I get a good calibration (?) only to have an error when first starting up
     
  11. bbfpv

    Joined:
    Feb 3, 2015
    Messages:
    3,745
    Likes Received:
    1,092
    Location:
    Long Island, NY
    Probably a bug. Ignore it unless it comes back after the cold IMU cal.
     
    FASTFJR likes this.
  12. FASTFJR

    Joined:
    Nov 7, 2013
    Messages:
    1,201
    Likes Received:
    169
    Location:
    South East PA
    Thanks
     
  13. Spry25

    Joined:
    Aug 20, 2015
    Messages:
    10
    Likes Received:
    5
    I had similar issues and recalibration after 15 minutes in the fridge fixed it.
     
    FASTFJR likes this.
  14. FASTFJR

    Joined:
    Nov 7, 2013
    Messages:
    1,201
    Likes Received:
    169
    Location:
    South East PA
    Just a quick follow up. I put the P3 Pro in the fridge for one, recalibrated the IMU and everything seems to be fine. No IMU error message on start up and the "Warm Up" message went away after 10-15 seconds. I did not realize the P3 has a little heater to warm up the sensors
     
  15. Kevin Paluch

    Joined:
    Aug 25, 2015
    Messages:
    8
    Likes Received:
    1
    The imu reacts to temperature when you calibrate. I placed mine in the fridge for 10 minutes and then calibrated. It warms up instantly!