I2C communication is master-controlled. The master initiates, manages, and terminates communication, generating the clock signal.
The master sends the 7-bit unique address of the target slave, followed by a R/W bit (0 for write, 1 for read). I2C Overview
The master releases the SDA line to high while SCL is high, signaling the end of transmission. Advantages and Limitations Understanding I2C I2C communication is master-controlled
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. The master releases the SDA line to high
SDA and SCL are connected to a voltage source via pull-up resistors, allowing devices to pull the lines low without creating short circuits.
Data is sent in 8-bit bytes, most significant bit first, with each byte followed by an ACK/NACK bit.
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).