Read 10 or more switches using only two I/O pins of a microcontroller

摘要

There are several ways to read multiple switch inputs using a reduced number of microcontroller-unit (MCU) pins. For example, you can use an analog MCU pin to read multiple switches by assigning a unique voltage to each switch through a resistor network, or you can use a one-wire device, such as the Maxim DS2408 8-channel addressable switch.