Caveat: I bought one of these boards (labeled "ZYPDE" "YZXSTUDIO") that supposedly had soft programming capability--you hold down a button for the right amount

Caveat: I bought one of these boards (labeled "ZYPDE" "YZXSTUDIO") that supposedly had soft programming capability--you hold down a button for the right amount of time and it programs it to produce 5v, 9v, 15v, etc the next time you turn it on. But it never worked. It always came up in a mode where you had to push the button the right number of times to get the voltage you wanted. I like the idea of DIP switches or soldered jumpers much better.