MINIMOSD STOPS OVERLAYING DATA

Hello there,
I have decided to start a new discussion on this subject as I can't understand why from time to time and without notice, my Minimosd will clear the screen from data overlay and what I get is clear video from cam. all looks to work perfectly before this happens and sometimes, too often I would say, Overly disappears without any notice.

first of all, I would like to know if I am the only one who suffers from this symptoms.
If any of you out there experienced or experiencing the same phenomenon, please come forward before I loose my sanity :-)

 

My Setup:
APM 2.76, minimosd extra r710, 3dr hw ver 1.1, 3DR telemetry. OSD is powered from APM 5V ( parallel to telemetry port without TX connected - only RX,GND, +5V), all soldering pads are soldered. Voltage is constant at 5.20V at all times.

Please remember - all looks to be working great, and out of the blue overly goes away like an invisible hand pushed this non existing OFF button which by then switching panels stops working - no control over OSD.

this can happen just like that without doing anything, or when switching to RTL using my remote control,  etc..

This happens with two of my identical minimosd's.


Thanks U.

 

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Replies

  • Hi, I was the one to start this thread because i was so frustrated with my MinimOsd boards - such a great small device and still always failed. i can now say that two years down the road (Hard to believe more then two years passed since) and my issues are almost solved completely by utilizing a very big 550000uf capacitor on the 5V rail. since then i can recall maybe two times where i lost the overlay while first powering the plane before take off but not during flight. so clearly the problem was related to power - either instability or lower then required.

    • I tried almost any way of powering minimOSD. Currently I use external 5V bec (exactly 5.00V) to power only minimOSD. Also added lot of capacitors on input (electrolytic + ceramic + tantalum). Everything works great on ground but as soon as I take off and do more aggressive movements overlay disappears.

      I thought that camera could be source of these problems so I tried few more CCD cameras. No success, same problems occur. Silly idea was to mount GoPro Hero 4 directly on multirotor and guess what? No matter how hard I push aircraft overlay stays stable. But I cannot use GoPro for FPV, it is expensive and these cameras are nor reliable as Security cameras. 

      Now I tried to use NTSC CCD camera to see if it solves my problem but as soon as I connect this camera overlay disappears. By disconnecting camera overlay instantly appears. Of course, I selected NTSC in minimOSD configurator. 

      More than one year I'm trying to solve my problems, without success, grrr.

      • Some cameras are not compatible with the MAX chip on the MinimOSD. perhaps thats your issue?

        You could also try a LC filter after the BEC before the OSD.

      • I know *exactly* what you mean.
        Let me tell you why you're here. You're here because you know something. What you know you can't explain, but you feel it. You've felt it during your flights, that there's something wrong with MinimOSD. You don't know what it is, but it's there, like a splinter in your mind, driving you mad.
        It is this feeling that has brought you here..

        :-)

  • I found the video chip on the MinimOSD is very sensitive to voltage. I think anything below 4.9V and it resets itself. I add a big cap on input to the OSD, and never power it off the same 5V as servos, because they cause huge voltage spikes.
  • Ok I have been following this and other threads about the same problem for months with no joy until today when I had my first ever completely successful flight with a minimOSD!!!

    I tried almost all of the fixes and suggestions mentioned here with not much success and still could not get the board to perform outside of the house.

    Indoors no problem even with the motors going full blast sold as a rock. Take it to the field I see the board boot up request data from the APM and vanish leving me nothing but video.  So what has changed I here you all say??

     To answer this properly will take a great deal more exploration sins as I said I have played around with a lot a different possible solutions some of which were still in place today.

    1) First off I never did solve the problem of getting the RS0 parameters to not revert do defaults so for me that was a dead end.

    2) I powered my OSD from an independent BEC on one side only 5V.

    3) The camera is powered from the Video Transmitter but the earh from the camera goes to my OSD

    4) MinimOSD-Extra worked for me on everything but the battery voltages which I never managed to fix so I reverted to the original 2.2 firmware where at least when Indoor's and working !!!! everything worked.

    5) I tried placing a 220uF 10v Cap across the Pos and neg pins to help regulate the voltage which is still in place.

    6) Lastly and this is where it started working outdoors in the field I went back to the minimOSD setup and put some entries into the second Panel which up until know I have nothing configured in. My thinking here was that suppose something was triggering the OSD to switch panels from 1 to 2 and I had nothing in 2 therefore would see no image!!! 

    Know it so happens that when I did this I noticed that my board was configured to allow switching panels on ch8 so I turned this off also. I have to say however I have had so many attempts at fixing this and have checked most times that panel switching was disabled that I don't think this could have been the only fault. However I now have a working all flying minimOSD three boards and a great deal of lost hair later. Which combination of these fixes did the trick I have no real idea.

    Surely its time for a new OSD for the APM community there has to be an easier way.

    • Nice find Colin. I'll try that too. It really makes sense.

      After shielding all cables from OSD I managed to reduce these problems noticeably. But I still get problem with overlay when doing aggressive maneuvers.

      I'll try your tip and report it here.

  • I have the same issue of lost overlay in multiple copter configurations, many times, i might have a strong clue here:

    While i was flying in the proximity of some RF antennas towers, both minimosd and gimball controller stopped working. They have in common long wires going out to camera respectively to IMU sensor. It seems that long wires act like an antenna and disrupts the max7456.

    Once i flew with my copter immediately after a storm and static electricity from air caused MAX7456 eeprom data coruption, the osd showd chinese :) I had to upload the character set again and everything got back to normal.

    So it seems that the situation cames from max7456 itself, not from APM or atmega328 controller.  Any ideea how this should be approached? I'll try to mount some rf filters and see what will happen.

    • Hello Dragu Mihai,

      it makes sense but I have these problems even on clear day far away from antenna towers.
      I tried almost everything to solve this problem, nothing helped.
      Problems occurs mostly when I give higher throttle, rotate or it is windy. (When motors change its RPM quickly) So it must have something to do with motors.

      My first thought was defective OSD so I bought another one. New one is more tolerant but overlay still disappears within 20-30 seconds.

      Tried to use separate power supply for 5V and 12V stage, tried to power second stage from Pixhawk, tried to use separate bec (5.2V). Even tried to solder additional tantal and ceramic capacitor directly to 5V and 12V pins.

      Yes, I have long wires from OSD to Tx (about 40cm) but why is it so sensitive?

      Only what I can additionally do is to shield these wires with aluminum foil...
      As soon as I try it I'll report it here.

  • Guys,

    Finally i fixed my issue with the OSD, There are few things i did but i dont know what exactly helped.

    First the switch mode BEC could create harmful emf and that can cause certain issue if you keep a device close to it. Buy a BEC that's shielded or keep away from the osd wires as well as the device itself. This could cause OSD to stop even though power line fairly smooth.

    Second I changed the OSD firmware back to 2.0 from 2.2. This could potentially help but i don't see why.

    BTW cable that goes from the APM to OSD; make sure cable is nicely twisted or to gather. If there is excess wire laying around make a ring out of it. Finally keep the data cable out of the motor wires and esc's as much as you can. I didn't realize how harm full it could when there is alternating current goes though a wire. 

    I hope this helps to figure out whats wrong with you OSD's.

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