We've already introduced external network connectivity relative to Ethernet and wireless technologies. There are many different communication interfaces that are more traditionally associated with embedded devices and are commonly available as hardware peripherals on an MCU. The interfaces that are used for communicating with on- and off-board sensors and actuators are as follows:

• Inter-IC Communication (I2C)
• Serial peripheral interface (SPI)
• Universal Synchronous/Asynchronous Receiver Transmitter (USART)

The following peripherals are regularly used in automotive and industrial environments for inter-module communication:

• USARTs
• Controller area network (CAN)
• Local interconnect network (LIN)