The ARD-DCCSHIELD is an optoisolated interface shield for connecting an Arduino (as a decoder) to a model railroad DCC control system. Additionally, the board has provisions for sending a DCC ACK pulse, connecting I2C accessories and general purpose I/O lines, as well as optionally (jumper selectably) powering the Arduino off of DCC power and providing up to 400mA of 5VDC to connected circuitry.
The board is designed to be compatible with various DCC decoder libraries and Arduino boards. We typically use Alex Shepherd's excellent NmraDcc library.
Note: The board implements the functionality necessary for being a decoder. It does not implement the ability to generate DCC signals (ie, act as a command station).
All documentation, source code, and hardware design files are in the ARD-DCCShield Project on Github.