Practical IoT Hacking

8 SPI and I²C

This chapter introduces you to the Serial Peripheral Interface (SPI) and the Inter-Integrated Circuit (I²C), two common communication protocols in IoT devices that use microcontrollers and peripheral devices. As you learned in Chapter 7, sometimes simply connecting to interfaces, such as UART and JTAG, gives us direct access to a system shell, maybe one that the manufacturers left purposely. But what if the device’s JTAG or UART interfaces require authentication? Or worse, what if they’re not implemented? In those cases, you’ll still likely find older protocols like SPI and I²C built into the microcontrollers.

In this chapter, ...