Two-wire bus with addressable devices and pull-up resistors.
I²C uses two open-drain lines, SDA and SCL with pull-ups, 7-bit addresses, ACK bits and speeds 100 kHz–3.4 MHz. Multi-master with arbitration. Pull-up value depends on bus capacitance. Great for sensors and EEPROMs.
An IMU and OLED share one I²C bus at different addresses.
I2C connects many devices on two wires, which is very convenient for sensors and small peripherals.
Two-wire bus with addressable devices and pull-up resistors.
I2C connects many devices on two wires, which is very convenient for sensors and small peripherals.
The bus lines are open drain, so pull-ups are needed to bring them high, and their value sets the rise time and power.
A seven-bit device identifier sent at the start of a transaction, which lets many devices share the same two wires.
Typical applications include connecting a temperature sensor and an EEPROM to one microcontroller, reading a real-time clock chip over a shared bus and configuring a camera module with a register interface.
Study "SPI" first (topic 65 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
Start and stop conditions. Clock stretching. Address conflicts need multiplexer.
An IMU and OLED share one I²C bus at different addresses.
The next topic is "CAN bus", which builds directly on this one.
It is classed as Intermediate in Electronics & Embedded (topic 66 of 104). It is an intermediate topic. Work through the beginner topics in Electronics & Embedded first.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.