Data is sent in 8-bit bytes, most significant bit first, with each byte followed by an ACK/NACK bit.
I2C (Inter-Integrated Circuit), often pronounced "eye-squared-see" or "eye-two-see," is a popular, synchronous, multi-master/multi-slave communication protocol invented in 1982 by Philips Semiconductors (now NXP). It is used for short-distance, intra-board communication between a processor and low-speed peripherals such as sensors, LCDs, and memory chips. Its hallmark is using only two wires for communication, making it highly efficient for managing multiple devices on a single bus. I2C Overview
The master sends the 7-bit unique address of the target slave, followed by a R/W bit (0 for write, 1 for read). Data is sent in 8-bit bytes, most significant
SDA and SCL are connected to a voltage source via pull-up resistors, allowing devices to pull the lines low without creating short circuits. Its hallmark is using only two wires for
Each slave device has a unique 7-bit (or 10-bit) address, eliminating the need for complex Chip Select (CS) lines used in SPI.
The slave device with the matching address responds with an Acknowledge (ACK) bit (low), signaling it is ready, or a Not Acknowledge (NACK) bit (high).