Discussions

MinimOSD - Black screen/no image

Posted by Jérôme Niklès on May 10, 2012 at 12:45pm

Hi all !

I need help about my MinimOSD freshly unpacked.

I've triple checked the cabling and I don't know why I've just a black image on my screen.
There is a suspicious comportement when I power on the system. I explain how it happens:
1. Connect correctly the Vin/Vout/RX/BLK between APM, MinimOSD and video transmitter 
2. Power on the APM 
3. Connect the battery balance connector 12V to the MinimOSD  

At point 2, the ST led (orange) blink and the D PWR (red) led power on and still.  
When I do the point 3, the ST led shut off and the A PWR led power on and still. 
After that, I just have a black screen... It's weird because the system worked at least once!  
The firmware is up to date and I use a XBee but I've not connected the TX port on the minimOSD.

What's wrong ? Someone can help me ?

Thanks in advance ;-)

Jerome

You need to be a member of diydrones to add comments!

Join diydrones

Tags: minimosd, black, image, issue, no, problem, screen
Email me when people reply –
Follow

Replies

  • gustavo April 2, 2013 at 1:44pm
    Jerome,
    Cold you please tell me what your final configuration was , and if your chip is not heating up now?,
    Thanks
  • Josh Potter December 13, 2012 at 6:00pm

    I've been powering mine directly from my main 3 cell battery and never had any problems.  I'm using the 1.1 rev, any ideas why I'm not seeing this problem?

  • steve October 15, 2012 at 4:56am
    Jani do you see anything wrong with the way I set it up? I've never had the black screen problem but after reading these posts I want to make sure I don't have the problem :) are my grounds isolated because I'm using switching reg to power apm and another to power video side of OSD because I use 4S so can't power video side directly with that so I use second 9v switching reg just for that.
  • Developer
    Jani Hirvinen October 15, 2012 at 4:04am

    Hmm I don't know what happened to my earlier message so here goes again, I hope that it will come trough fully now.

    MinimOSD has two power areas, one digital and one analog. Digital area is normally powered directly from APM and with +5V (4 pin telemetry cable). Analog side can be powered from battery directly. If your board have switching regulator, you can power it from 2-6S LiPos easily. If you don't have switching regulator then maximum power is around 3S LiPo. 

    jDrones miniOSD's have always been having switching regulator. Goodluckbuy etc do not have as they are using old design. 

    How to know if you have or not have switching regulator. Look top right corner of your OSD on above of Video IN/OUT pins, if you only have one small IC there and a lot of space around it.. You don't have switching regulator, but if you have a lot of components and especially one square components with white sticker on it, Yes in this case you do have switching regulator and you are free to use 2-6S LiPo's

    Using one power source only, there are small solder jumpers on board that can connect analog and digital areas together and this way use only one power source. One jumper is on Bottom of the PCB (around middle, on jDrones board it is just above letters "ro") and another jumper is on Top side of the PCB between those small resistors/capasitors under square MAX7456 Video IC.

    IF you connect these two jumpers, then you only need to provide one power source from Video PINs area. Also if you connect these jumpers, do NOT connect +5V from APM. I say NOT just in case, nothing bad will happen but if you have another switching regulator powering APM you might have power conflicts and that can cause crashes.

    Reason to have two sources is that some systems don't like that we mix analog and digital power sources together, 

    We 2S users, don't worry we use a lot of 2S LiPos to power up our OSDs while doing testing and other things, only bottom silk says +12 on Video PINs area.

  • steve October 15, 2012 at 3:27am
    I have a jdrones 1.0 board which should have the switching regulator and have had no problems with it. I use a 4s battery for everything and power my apm1 with 5v 10a reg from castle creations and since my Pixim camera requires more than 5v I have a second castle 10a reg that I changed to output 9v. Even though I'm using one battery for all I guess my grounds are isolated because I've never had this problem of black screen. On the video side I have all 4 wires connected. Video in out and +- also.

    Does anyone know if I could do the same thing with the dc-dc buck converter. The castles are really overpriced in comparison!
  • Fête Mobile July 25, 2012 at 1:14am
    Hi Andre. I fried the latest revision hardware (with the switching regulator), and have switched back to the v0.1 hardware. I've removed the centre pin from the in/out headers and so far so good...

    Thanks, Gábor, for your code change. I had a solder blob on the back of the board to default to PAL, but it wasn't working, it seems. Works fine now. No extra reboots required.
  • Fête Mobile July 23, 2012 at 7:09pm
    I did a bit of testing and can confirm that using a V0.1 minimOSD powered by the APM works. I haven't fried this OSD (at least not yet), but have been careful to power up the APM before the video system. I have added solder blobs to the back of the board to tie the analog and digital power rails, and have removed the V+ pins from the pin headers that connect to the video in/out connectors.

    I'm not sure why this is, however, but I have to cycle power to the APM after the minimOSD boots up. Otherwise, I just get the video passed through with no OSD at all. Can anyone comment on why this might be or other workarounds?

    I'll keep testing with this miniOSD and hope I don't fry it. I hope this hardware flaw is repaired so the minimOSD firmware can continue to improve.
  • Fête Mobile July 19, 2012 at 10:30pm
    I bought two minimOSD modules: a 0.1 and the 2.0 version (with the switching regulator). Just before my second flight out I fried the 2.0. I hadn't read the warnings from this thread but suspected a grounding loop fried it. I was, needless to say, a bit miffed. I had powered the video system before powering the ESC.

    What's the point of making a super-small OSD if it requires a dedicated battery? I got it for small drones, after all. I hope that someone can solve the self-destruct hardware flaw as the firmware is coming along nicely.

    I have been using the v0.1 model (powered by the APM). As a precaution, I now power up my drone as follows:

    * Power to the APM/ESC (via deans plug)
    * Power to the video system (via the balancing header)
    * Wait a few seconds and cycle power to the APM, as the minimOSD won't boot otherwise.

    As an additional bit of OSD flakiness, I note that if I power up the OSD and am getting good video, but then take off the lens cap, I lose the OSD. Cycling power to the APM brings the OSD back. I'm going to test this bug more tomorrow as it sounds a bit too strange to be true.
  • Patricio June 3, 2012 at 9:15pm

    Jerome, i am in the same situation than you. No video output on the minimOSD. I got this unit from jdrones but have been unable to get support from them.

     

    Did you Have any  luck on resolving this?

     

     

  • vilnis.lauva May 11, 2012 at 12:07am

    Do you use the same battery for video and APM ?

    Sadly I blow out two minimOSD, first one by don't knowing it, second one just accidently. If you use common ground on video and data input (and by using one battery you definitely do that) your minimOSD is dead.

    There must be huge red letters in minimOSD wiki not to do this which can looks like normal thing like common ground.

    Now I just want to know what exactly blows out, maybe diydrones can give some helpfull hand. I changed max chip, but still no picture, atmega works fine.

This reply was deleted.

Activity