The Inter-Integrated-Circuit protocol, more commonly known as I²C, was designed around daisy-chaining. With I²C, multiple “slave” devices can communicate with one or more “master” devices. The protocol uses two communication pins: a serial data line (SDA) which is shared by both the “master” and “slave” devices and a serial clock line (SCK) which the master controls. The I²C standard requires four signals, serial data (SDA), serial clock (SCK), ground (GND) and power (VCC).
Prior to 2018, our I²C Pmods were designed with a 2X4 male pin header for daisy chaining. As of Digilent Pmod Interface Specification 1.1.0, I²C Pmods are now designed with a 6-pin male header on one end and a 6-pin female header opposite. This allows for daisy chaining, through the use of an onboard jumper, and improves the mechanical compatibility within the Pmod ecosystem.
Click here to learn more about I²C.