A common way to expand the set of available output Pins on the Arduino is to use shift registers like the 74HC595 IC. 74HC595 IC needs 3 pins to control these chips – Clock, Latch, Data and increase the number the Pins.

The MCP23017 is the all-singing-all-dancing Arduino port expander with 16 I/O pins and it gives you virtually identical pin capability to the existing pins of a microcontroller. They can be individually set to input or output and you can enable an internal pullup (also individually).

Jul 16, 2020 · Port expanders can be used to create extra GPIO pins on the Arduino. In this tutorial, we will learn how to use port expanders by building a project using the MPC23017 port expander to create two additional 8-bit ports and read and write to them using I …

Nov 19, 2022 · In this guide you will learn how to use the GPIO expander MCP23017 with Arduino. It enables you to add up to 128 GPIO pins using only two pins on your Arduino. If you sometimes don’t have a enough GPIO pins for a project then this is the tutorial for you.

The IOExtension module is based on four shift registers (74HC595) to provide 16 Digital Inputs and 16 Digital Outputs, you will need only four pins in your Dev Board to control the module, plus the Vcc and the Gnd pins.

Connect I2C SCL and SDA lines to same on the MCU. If used, connect the INT line to an interrupt input on the MCU and use a pull-up resistor. I write a library to use i2c pcf8575 IC with arduino and esp8266. I try to simplify the use of this IC, with a minimal set of operation. I2C works with it’s two wires, the SDA (data line) and SCL (clock line).

Jun 21, 2013 · Using a MCP23017 port expander costs 2 pins and gives you 16 leaving you with 14 up BUT you can connect 8 of them with the same two pins giving you 128 pins leaving you with 126 up. And unlike a shift register the pins are individually addressable and there is no penalty for cascading them.

This "GPIO (General Purpose Input Output) pin extender" provides an additional 8 pins (P0 ~ P7) which can be used to 'output a signal' or 'read a signal as an input'. These modules run on the I2C bus, and if daisy-chained you can connect upto 8 of these devices in a project.

Dec 24, 2023 · Arduino port expanders can be used to give your Arduino projects additional inputs and outputs. By connecting an Arduino port expander to the I2C bus of your Arduino, you gain access to a variety of digital input/output (I/O) pins, which can then be …

Too few pins on your Arduino? Use this I2C controlled pin extender (with optional interrupt) to make life easier! This supports my YouTube channel https://www.youtube.com/c/RalphBacon, and specifically video #49 PCF8574 Pin Extender. There are three sketches here, starting with the simplest one, an LED flasher.