BOTH I2C AND SPI ARDUINO SERIAL

CS : Chip Select ( active low signal from main to address subs and initiate transmission).MISO : Main In Sub Out (data output from sub).MOSI : Main Out Sub In (data output from main).

BOTH I2C AND SPI ARDUINO SERIAL

SCLK : Serial Clock ( clock signal from main).SPI has four logic signals (which go by alternative namings): Each device internally uses a shift register for serial communication, which together forms an inter-chip circular buffer. (Note: Variations section describes operation of non-standard variants.) Figure 1: Basic SPI configuration using a single main and a single sub. SPI may be accurately described as a synchronous serial interface, but it is different from the Synchronous Serial Interface (SSI) protocol. Typical applications include interfacing microcontrollers with peripheral chips for Secure Digital cards, liquid crystal displays, analog-to-digital and digital-to-analog converters, flash and EEPROM memory, and various communication chips. It is sometimes called a four-wire serial bus to contrast with three-wire variants which are half duplex, and with the two-wire I☬ and 1-Wire serial buses. Motorola's original specification uses four wires to perform full duplex communication. SPI uses a main–subnode (master/slave) architecture, where one main device orchestrates communication by providing the clock signal and chip select signal(s) which control any number of subservient peripherals. Serial Peripheral Interface ( SPI) is a de facto standard (with many variants) for synchronous serial communication, used primarily in embedded systems for short-distance wired communication between integrated circuits. This article may need to be rewritten to comply with Wikipedia's quality standards, as it reads like a guide or textbook.

Both i2c and spi arduino