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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Started searching all possible discussions.

found this: http://diydrones.com/forum/topics/minimosd-board-have-athermal-cut-out

very similar to my problem but can't see any comments / solutions. 

Did you try the original Minimosd software ? This is what I did when I experienced freeze with extra 2.2, just to be sure it's a software problem, or not.

Maybe the Mavlink telemetry stop, or some rates are incorrectly set on SR3. Just guessing.

Thank you Bravojul for trying to help. Trust me to try almost everything possible.

what I did notice is that minimosd, regardless if It's running extra 2.4 r710 or 2.2, sometimes does not read Mavlink as the yellow led sometimes stops blinking and when it stops, I get no data overlay.

I am not sure if minimosd needs to requests mavlink messages or APM pushes these anyway and regardless.

this might give a clue.

SR3 parameters are as advised here:



This is becoming quite annoying.


Minimosd displays data when they come in. No need to ask. When you have a 3dr radio in parallel, it is advised to remove the link from the minimosd to the apm. I see that you did exactly that, so it should work.

You didn't say what was the outcome of trying 2.0 from here : http://code.google.com/p/arducam-osd/downloads/list

Hi Navigant,

Could you post some pictures of your setup?

What I would like to see:

1 - minimOSD FTDI pins connection

2 - Video pins connection

3 - minimOSD board overall picture

4 - 3DR radio FTDI pins connection

One important test:

When your osd goes off please check if telemetry is still sent to Mission Planner via 3DR radio.


Thanks Miguel, I will upload some pictures.

1 - minimOSD FTDI pins connection -  Only RX, GND, +5V

2 - Video pins connection - Only Signal and ground are connected to both cam and TX - no power.

3 - minimOSD board overall picture - will send later.

4 - 3DR radio FTDI pins connection - Original cable from apm telem to ftdi plug. not really relevant since I have continued my tests after disconnecting my Telemetry module and still OSD clears from time to time.

One important test:

When your osd goes off please check if telemetry is still sent to Mission Planner via 3DR radio.


what I have noticed last night is that I get this flashing yellow led on minimosd board to stop flashing with adviced SR3 parameters following by lost of overlay. when I have changed these to the SR3 parameters I found last night, I could not get this yellow led to stop flashing. what I want to say is this:


when with adviced SR3 parameters, each time I reset the board, when initializing complete  - Yellow led sometimes blinks (communication and overly on) and sometimes after reset it wont blink - in that case no communication - no overly.


when I have changed the SR3 values, and it's very preliminary results as I am due to have more tests later today, It was obvious that each time I reset minimosd - the yellow led came back flashing and overlay was working,


so, I will do some more tests and will come back with pictures.

Thank you all so very much for helping me out.


How do you manage to get an image if you don't provide power to the minimosd video stage ? (according to your point 2 - )

Hi Bravojul

I power both Camera and TX separately.

the middle pins, the ones that are +12V were taken out from these servo plugs connected to MINIMOSD analog side.

these two are soldered together and being fed by main 3S lipo (+12V) . Lipo (-) is connected to minimosd analog outs ground pins.

I did this cause I was reading lots of users got their osd's to either brownout or very hot.



Went to sleep when I had issues.

Came back from work, did some OSD flashing, APM SR3 changes, and now, after 1 hours playing with the system, and I can't reproduce what I was experiencing at 3am in the morning. so far, system works, but I will be the last person on earth to open up my champagne. not yet.


What I did is this:

saved my APM params with SR3 settings as I always had. called it "OLD_SR3".

changed SR3 settings, wrote these to APM. saved a copy called NEW_SR3.

then, I reloaded the "OLD_SR3" params followed by me re-flashing my OSD with latest 2.4.r710. flashed it twice.

then, I re-practiced what I did at 3am which was resetting osd every few seconds. early morning and every second or third reset, I saw mavlink / yellow led on osd stops flashing and no overlay.

now when I reset the osd every few second, I was never able to get read of the overly - it always came back!


even though these are good news, I don't like this :-) as I can't reproduce and know why now the system behaves as it should

I will do more tests but the real test will be out on the field. Can you relate to what I did and the outcome of things?

this is by all means not a real test but the odd thing is that I can't tell why now things behaves differently.

can it be that flashing a chip will not be 100% ok and with errors but still operate?

I will now open up a bottle of beer and will keep pushing this reset button till I fall asleep or overly will go away - which ever comes first.





Hi Miguel.

Do you know if this Yellow led I am talking about, the one on the OSD which blinks when it receives data stream, - is it pure hw indication, or you need OSD code to enable this?

This might give an indication whether the problem is with minimosd or APM.



I think i know why is this.

It is that i have modified the values for switching, to allow the use of the same channel for mission reset also.

I have added a detailed description about this, in downloads.


Hope that this was it.


Hey Gabor!

I am not using a 3 way switch but a push button.

I have checked my PWM and saw that the pulse was between 1000 and 1844, so can this have caused my problems? I have now reduced the toggle span to be:

Idle :1000

Pushed: 1680 ( Instead of previously 1844)

Have I understood you correctly?


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