What is "SPI"?

"SPI" stands for "Serial Peripheral Interface" and it is a synchronous serial communication interface used to transfer data between microcontrollers, sensors, memory devices, and other digital integrated circuits.

In an SPI setup, there are typically two devices: a master device that controls the communication and one or more slave devices that receive and transmit data. The master device generates a clock signal and sends data to the slave devices on a MOSI (Master Out Slave In) line. The slave devices send data back to the master on a MISO (Master In Slave Out) line. The clock signal and chip select signals (one for each slave device) are also sent by the master device to control the communication.

SPI is a full-duplex communication protocol, meaning that data can be transmitted in both directions simultaneously. It is also a synchronous protocol, meaning that the timing of the communication is controlled by a clock signal. The clock speed and other characteristics of the SPI communication can be configured in software by the master device.

SPI is a popular interface in embedded systems and is used in many applications, such as data acquisition, sensors, displays, and memory devices. It is a relatively simple and fast interface, making it suitable for many real-time applications.