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 ;-)


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I think that it is safer to connect the digital & analog grounds together as well. At least mine is wired this way now and it is still alive after many tests.
Two remarks:
- I haven't noticed any visible parasites on the video  (even when using (cheap) servos & motor).
- In my case, I observed that this problem [=death of the max chip] arised just at the moment when I connected (or disconnected?) the digital and/or analog power, and not  during in a "steady state" use (it is probably a transient voltage that kills the video chip).

Hi Ronny! Please, double check your connections and the board for some other issue. The chip should NOT fume just because the two stages are not tied. The max7456 "analog gnd" and the "digital gnd" are engineered to work that way apart from each other if you need that.

For more details, please check it here: http://code.google.com/p/arducam-osd/wiki/How_to_start_minim

Hi Sandro! I have checked the connections and the video link is working when bypassing the OSD, when board is connected there is only black screen, i can still connect the config tool and update software but thats all...

2 new boards on order... plus extra 7456chip

Regards Ronny

Hi Sandro. I agree that the two grounds need not be connected, but the max7456 datasheet also specifies that the voltage difference between the two grounds (AGND & DGND) should not exceed 0.3v, which is quite small. This is not a "typical" value, but an "Absolute maximum rating"...  So, if they are not connected one must be careful, in particular when connecting/disconnecting the analog or digital power lines.

What hardware version do you see printed on your board? Is that from 3DRobotics?

HobbyKing and others did clone the old version which has a linear regulator. It gets really hot with 12V at the video IO pins. Even worse is that they usually sell it wrapped on a heat-shrink.

I Have a 3d robotics arducopter with minim osd , directly wired from factory , and it got burned , so it is so clear tha t the design is flawed that I can't really believed that a this point nobody from design has was successfull to clarify how to properly connect .this card , not two or three different setups , but the one that is right.

The sure fire way is to power it from the 5v side only and bridge the 2 solder gaps. Powering it with 2 batteries is a recipe for smoke :)

Yep. I know that it's from -0.3V to 0.3V. However, I did test it so many times at so many different ways, and different boards... it never was a problem here. The suggestion of a transient "punch" makes sense though like a troublemaker. I'll talk to 3DR guys about it.

Anyway, my original design had no that option.  I personally do prefer tying the two stages. It was a good intention on the current design, but looks like it's figuring as a weak point.

Just a thought: If the noise is a problem when tying the stages, we can still power the board from the switching power of the second stage with a dedicated battery (not connecting the VCC from the telemetry, of course). It should minimize that kind of issue.

I used the genuine 3DR 1.1

but I have now ordered a HK.....

Mine is also showing black screen only.

If bypassed all is good.

From the start i used two bats. One for APM and one for VTx Cam and OSD.

Do i need to connect two GNDs together for it to work???

Anyone can help me with the ISP pin order on the MinimOSD, I have an AVR programmer and a FTDI cable and I understand that if I want to burn the bootloader I have to use ISP connector ? I don't know the order of the pins on the minim OSD

PS> I'm also seeing a black screen, andnever used 2 different batteries with this board, I first started it without powering the video side, I forgot to solder the two pins, than I soldered the pins so the video side will be powered from 5v supplied by FBOSD but I could see only a black screen. Before this there was no signal sent on the video cable, now MinimOSD is sending only a black screen and it seems I can't anymore update the firmaware, or upload any sketch using arduino IDE ...or any other config tools :(

Any suggestions are welcome. 

Thank you.

I want to share what I've learned and also get some advice before I proceed with the next step.

It was always my intention to power my entire video setup with a single battery to keep it all isolated and clean. I have a small 200mw transmitter, a genuine 3DR MinimOSD, and a gopro. The video tx can be powered with a 1s lipo at minimum voltage. It runs at 3.3v.

Turns out the MinimOSD is also running soundly on a discharged 1s lipo, which is the size of a pack of gum.

I have the analog and digital sides tied together with the solder jumpers. The ground on the video side ties to the battery, The GoPro, the OSD, and ends at the Vtx. The positive side of the battery is not connected to the OSD at all.

For testing, I have another tiny lilo powering the 5v side (again, I am NOT powering the other side, only passing through a common ground.

I want to do it all on one battery. I feel like the ground between the 5v side and the other side is already tied together because of the solder jumpers. I just want to make sure.

(Final thoughts: I thought there was a brownout fuse on the OSD that would kick in at 4.1 volts, but it keeps chugging away with no trouble right down to 3.8 volts. And there is no heat at all).

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