I'm confused
Wasn't the original idea;
Isolated from USB supply.
NO USB communication because it couldn't be isolated, and would considerable up the cost if it was.
Fits into a small box with switches and display on the top.
No battery backup.
As simple but efficient as it can be.
Lots and Lots of No's to other posters suggestions of control from the pc/laptop.
Now we have buttons on the side, USB interface chip, battery backup, menu options and a soft on/off switch.
Or has it been sooooooooooooooo long since Dave started this that I've missed something major.
Mr Smiley