Questions regarding Port or IO Expanders, be it I2C, SPI, 1-Wire, serial/uart or similar. Shift-Registers are normally NOT considered Expanders, and have their own tag.
Questions regarding Port or IO Expanders, be it i2c, spi, 1-wire, serial/uart or similar. shift-register are normally NOT considered Expanders, and have their own tag.
Port Expanders are typically addressable devices, with individually settable IO pins. They come in a variety of packages, with multiple features. Expanders can be Output only, Input Only, or both Inputs and Outputs. They can have interrupt features, PWM, and constant current options. They can be Open Drain/Collector or Push/Pull devices.
shift-register are similar, but are often only serial to parallel output only devices.
Addressable LED Drivers are also similar in use, except for having a niche target of driving LEDs. LED Drivers can easily be used as GPIO Port Expanders, either directly, or through a simple inverted transistor circuit.
