A FuriousFPV FTDI such as this one is required to program/update firmware on arduino based microcontrollers such as the MinimOSD.
In comparison to using a FTDI cable, this USB breakout board has TX and RX LEDs which provide a visual indication to verify that data is transferring.
USB TO UART Converter CP2102 for Arduino.
Download driver here:
Designed for PIGGY OSD.