Microchip MCP23017 i2c 16 input/output port expander

Add 16 additional pins to your microcontroller via an MCP23017 port. The MCP23017 uses two I2C pins (which can be shared with other I2C devices) and provides you with 16 general-purpose pins in return. You can configure each of the 16 pins as an input, output, input with a pull-up, or open drain. There is even the option to receive an interrupt via an external pin when one of the inputs changes, so you don’t have to poll the chip.

Use this chip with a voltage of 2.7 to 5.5 V (suitable for any 3.3 V or 5 V configuration), and it can handle or supply up to 20 mA from each of the I/O pins, making it ideal for LEDs and similar applications. If you need a high-power MOSFET, you can combine it with a high-performance MOSFET for more power. The DIP package means it fits into any breadboard or perfboard.

You can set the I2C address by connecting the ADDR0-2 pins to power or ground, allowing for up to 8 unique addresses. This means that 8 chips can share a single I2C bus – that’s 128 I/O pins!

For more information, please refer to the attached datasheet.

We even wrote an Arduino library with example code that allows you to set the pin state and read from and write to individual pins.