Paired with an ATMega, and you really have something ... The board has an unpopulated ISP header from the assembler, so pogo pins are the answer. How do you make a pogo pin jig?

The board is laid out in Fritzing with just a few parts including a crystal, a few caps, an ISP connector, and pins for a serial connector. Not much, but that’s all you need for a prototyping board.