AD75019 crosspoint analog switch

Paul over at Dorkbotpdx has written an article about his AD75019 crosspoint analog switch:

The chip is controlled by a big 256 bit shift register.  I just chained the 3 chips in tandem, so the shift register is 768 bits.

In the regression tester, I used 3 of these chips to allow any combination of the 48 signals (on the X pins) to connect to any of 16 signals (on the Y pins).  The 16 Y pins are connected as a 16 bit bus between these 3 chips, and the sets of 3 chips on the other boards in the tester.  This “anything to the 16 signal bus” approach is important for understanding the code.

For more details and the Arduino code for these AD75019 chips visit Dorkbotpdx webpage.