Leonard Pirate (NOT Leonardo !!) is also Arduino Leonardo clone. You can connect this into USB port easily (no cables!!) and enjoy Arduino environment.
Some Arduino ports (e.g. 3.3V, IOREF) was omitted.
I was inspired this from Bus Pirate. Bus Pirate is easy to control or hack SPI/I2C devices from CLI (Command Line Interface).
So, you can play with Bus Pirate clone, Bus Ninja!! (I'm Japanese.)
(Ian taught me Bus Ninja. This is not a syntax compatible, but it's also easy to use.)
I strongly recommend USB-A style. But, you can choose Micro-B with cable, when you build.
USB connector is EXCLUSIVE!! Do not load both A&B!!
I refered Arduino's github master blanch. pins_arduino.h
Most of parts could buy from Akizuki and Sengoku in Tokyo, Japan.
Fuse is difficult to buy in Japanese stores. I bought “NANOSMDC050F/13.2-2” of TE, from mouser.
I don't have any special advice for SMD soldering guys.
I omitted XTAL's silk print, so please see the picture below. Pins are on opposite angle. So, you need to care only long or short sides of a rectangle.
Please refer this board layout.
After soldering, please write bootloader to the 32U4.
You can burn with Arduino 1.0. Choose your Programmer, Arduino Leonardo for the boards. And just click “Burn Bootloader”. If you can't see “Arduino Leonardo” on your Arduino 1.0, please edit “boards.txt”.
Or, I ported “Bus Ninja” to this board. You can download hex file from here. And, customized “Bus Ninja” code is available on my github repository.
When you flash hex, here is the sample command.
avrdude -p atmega32u4 -c stk500v2 -P usb -F -U flash:w:ninja-leonard-pirate-atmega32u4.hex -U lfuse:w:0xCE:m -U hfuse:w:0xD8:m -U efuse:w:0xFF:m