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MCP23017 16-pin I2C IO-expander library for Arduino
This is a MCP23017 16-pin I2C IO-expander library for Arduino with interrupt change/edge support and extensive examples.
Library features
- I2C interface
- Input/output/read/write/toggle/mask control per pin or per 16-pins
- Configurable pullup per pin
- Interrupt change/falling/rising per pin
- Interrupt edge handled by the library, because the chip supports pin change / level only.
- Low-power support
- Generic examples / AVR / ESP8266 / ESP32 support
Hardware
The following targets are supported:
- AVR: UNO, MINI, Pro Mini 8/16 MHz, ATMega2560, Leonardo
- ARM: DUE
- ESP8266: Mini D1 & D2, NodeMCU
- ESP32: Lolin D32
Examples
Extensive examples are located here.
Documentation
Getting started LED blink
#include <Arduino.h>
#include <Wire.h>
#include <ErriezMCP23017.h>
// PORTA: pins 0..7
// PORTB: pins 8..15
#define LED_PIN 8 // Pin B0
// Default I2C Address 0x20
#define MCP23017_I2C_ADDRESS 0x20
// Create MCP23017 object
ErriezMCP23017 mcp = ErriezMCP23017(MCP23017_I2C_ADDRESS);
void setup()
{
// Initialize Wire
Wire.begin();
Wire.setClock(400000);
// Initialize MCP23017
while (!mcp.begin()) {
// MCP23017 not detected
delay(3000);
}
// LED pin output
mcp.pinMode(LED_PIN, OUTPUT);
}
void loop()
{
mcp.digitalWrite(LED_PIN, HIGH);
delay(1000);
mcp.digitalWrite(LED_PIN, LOW);
delay(1000);
}
Library installation
Please refer to the Wiki page.