This project is some early work I did on an automated test system for Teensyduino, which someday will verify nearly all the Arduino functionality on every board and also test most of the Arduino libraries.
The main idea, which began in November 2012, behind this test is the use of AD75019 switch matrix chips to allow the control board (on top) to configure which pins on the other 3 boards (the test boards, each with a different Teensy) connect to each other and to various peripheral hardware.