Turning an Arduino of virtually any sort into a simple AVR 6-pin ISP programmer is old hat ... and constitute the only chip on board a Leonardo or Micro. The catch? You’re going to have to ...

But why stop there? That’s what [Jeroen Brinkman] must have been thinking while creating the Programmer’s Macro Pad. Based on the Arduino Pro Micro, this hand-wired pad is unique in that a ...

Except, on the Micro, there is no actual serial bus involved in programming ... to be normal Arduino I/Os, but were give some commands to turn them on and off, as described in this SparkFun tutorial ...