Hello guys, 

Actually this is the most helpful place in the whole internet for me so maybe someone here will know what is going on. 
I'm using Arduino nano to flash MWOSD to minimOSD and get a lot of troubles. I can't get it working with arduino software and tried different things and always get the error that device isn't connected or something like this. When I connect only Arduino to PC everything seems to be ok. I can flash "epprom clear" successfully but when I connect it to minimosd I get the error all the time. 

I'm connected like below:

DTR => RST
TX => RX0
RX => TX1
5V => 5V
GND => GND



I tried swapping tx and rx cables with no success and then tried without RST => DTR connection (using only 4 cables = power and ground and TX, RX connected) and first time it was working. Then I realized that it doesn't flash anything to osd because LEDs are always solid on (like on the picture) i can disconnect it and it works only with arduino. Any ideas what can I do?

I tried to swap TX and RX, change COM port, install many drivers, toggle NTSC and PAL etc.
I get the picture on the googles but no OSD.

My wiring looks like this: http://x3.cdn03.imgwykop.pl/c3201142/com...JQEDg6.jpg

EDIT: Actually I couldn't get it to work with Arduino nano the solution was to use FTDI Adapter. Now it works perfectly.

It should be able to connect without DTR. One of my minims was refusing to flash, both leds were on - what helped was me powering OSD board the moment Arduino started uploading. Maybe try this. (EDIT: I was using FTDI, so can't comment if ardu nano pinout is correct)

Your diagram looks fine, only thing I would change is to move + and GND wires to pads on the side of the board (diagram below) - I know it seems pointless, but it actually improves stability of the board. 

Seems you took the photo with the attempt with TX->TX0 connection ?
Anyway, I used ftdi, but had similar problem until I used the first GND pin (on minimosd) instead of the one next to 5V (*GND* GND *5V* ... ). No idea why, but with the second gnd it just didn't work.

"It should be able to connect without DTR."
And it connects but I'm not sure how to even check that it flashed Minimosd instead of only Arduino. Is there any way to find this is flashed by some blinking led during flashing or so?

"One of my minims was refusing to flash, both leds were on - what helped was me powering OSD board the moment Arduino started uploading. "
I read about that also have to try it.

"Your diagram looks fine, only thing I would change is to move + and GND wires to pads on the side of the board (diagram below) - I know it seems pointless, but it actually improves stability of the board. "
Thanks for an info will try this also.

Seems you took the photo with the attempt with TX->TX0 connection ?
Probably I'm messing all the time with this I will also try solution with first GND pin. My friend will bring me an FTDI Adapter tomorrow so I will try with this first because It seems to work with this adapter.

The green LED should be blinking as an indication that its software is working properly. When you flash the miniosd with the Arduino, I find that connecting both grd connections up as a sure way to get the firmware to be flashed properly.

In my case i had to have connected DTR and grounds... dunno why but then it worked, before wasn't able to connect in osd config.

i'd recommend to try with FTDI as they are less complex (also ensure that you have selected correct board on arduino

eventually it might turn out that ie board that you have might be damaged so question is do you have a spare to test ?