I2Cderived

I2Cderived is a descriptive term used in embedded systems to refer to a design approach in which a wide range of system signals and functionalities are derived from or controlled via devices on the I2C bus. It emphasizes using I2C as a backbone to expand I/O, aggregate data, or generate higher-level signals without expanding the microcontroller’s native pin count.

Overview and mechanism

The concept relies on I2C-enabled peripherals such as GPIO expanders, analog-to-digital converters, digital-to-analog converters, sensor hubs, and bus multiplexers. By integrating these devices, a single microcontroller can monitor and control many subsystems indirectly, deriving outputs or interpretations from data collected over I2C. The approach is common in cost- and pin-starved designs where chip count and wiring need to be kept minimal. It is not a formal standard or protocol; rather, it is a design pattern or architectural description used in documentation and discussions.

Implementation patterns

Typical patterns include using I/O expanders to provide additional digital outputs or inputs, employing sensor hubs that fuse data from multiple I2C sensors, and leveraging multiplexers to route devices on a shared bus. Derived functionality may involve software processing of I2C data to generate higher-level signals, such as status flags, alerts, or coordinated control signals, all while the MCU communicates primarily over I2C.

Advantages and considerations

Benefits include reduced pin requirements, scalable I/O, and streamlined wiring. Limitations involve added bus traffic, potential latency, address management, and timing constraints. Designers must consider bus speed, power consumption, and fault tolerance when adopting an I2Cderived approach.

See also

I2C, SMBus, GPIO expander, I/O expander, I2C multiplexer, sensor hub.