While playing with newly arrived Micro MinimOSD and attempting to flash it with latest MW OSD software, I've discovered that offical tutorial, as well as many other are missing one tiny detail that makes whole process much harder than expected. In theory, MinimOSD just Arduino Pro Mini with additional hardware. So, in theory, you plug in your FTDI USB adapter and upload a sketch. But if you never worked with Arduino Pro Mini (like me, it was always Uno, Pro Micro, or barebone Atmega328) you might not know one detail. Yesterday it took me more than 30 minutes to figure out firmware upload is not working, while it should. So, another tutorial will be written.

Micro MinimOSD with soldered pins

Micro MinimOSD pinout


To flash MW OSD to Micro MinimOSD we will need:

  1. connect FTDI adapter to MinimOSD
    MinimOSD FTDI
    5V 5V
    RX TX
    TX RX

    Micro MinimOSD connected to FTDIThe thing that most of tutorials ommit, is DTR line. Without it programming Atmega on MinimOSD with Arduino bootloader will fail. Obvious for people using Arduino Pro Mini. Not so obvious for all the other,

  2. Connect FTDI USB to Serial adapter to a PC,
  3. Open Arduino software and open WM_OSD.ino from MW OSD software package,
  4. Select board: Arduino Pro or Pro Mini (5V, 16MHz) w/ Atmega328 Arduino Board for MinimOSD
  5. Select correct Serial port. For Windows users it will be one of COMs, for Linux and Mac /dev/tty.* serial port for FTDI on Mac
  6. Press Upload button and this is all. MinimOSD will be flashed with latest MW OSD software and will be ready to connect to configuration software that comes with MW OSD software package. But I will write about this next time...