FPGA/CPLD
Papilio DUO Development Board
The Papilio DUO is an Open Source FPGA development board designed with the Arduino Mega footprint. It has a Spartan 6 FPGA on the top and an AVR Atmega32U4 (the same chip used in the Arduino Leonardo) on the bottom. It has 54 I/O lines, dual channel USB, integrated JTAG programmer, 512KB or 2MB of SRAM, and an efficient switching power supply.