com.diozero.devices.MCP23017 Maven / Gradle / Ivy
package com.diozero.devices;
/*
* #%L
* Organisation: diozero
* Project: Device I/O Zero - Core
* Filename: MCP23017.java
*
* This file is part of the diozero project. More information about this project
* can be found at http://www.diozero.com/
* %%
* Copyright (C) 2016 - 2020 diozero
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
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*/
import com.diozero.api.I2CConstants;
import com.diozero.api.I2CDevice;
import com.diozero.internal.provider.mcp23xxx.MCP23x17;
import com.diozero.util.RuntimeIOException;
/**
* Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf.
* The MCP23X17 consists of multiple 8-bit configuration registers for input, output and polarity selection. The
* system master can enable the I/Os as either inputs or outputs by writing the I/O configuration bits (IODIRA/B).
* The data for each input or output is kept in the corresponding input or output register. The polarity of
* the Input Port register can be inverted with the Polarity Inversion register. All registers can be read by the
* system master.
* The 16-bit I/O port functionally consists of two 8-bit ports (PORTA and PORTB). The MCP23X17 can be
* configured to operate in the 8-bit or 16-bit modes via IOCON.BANK.
* There are two interrupt GPIOs, INTA and INTB, that can be associated with their respective ports, or can be
* logically OR'ed together so that both GPIOs will activate if either port causes an interrupt.
* A special mode (Byte mode with IOCON.BANK = 0) causes the address pointer to toggle between
* associated A/B register pairs. For example, if the BANK bit is cleared and the Address Pointer is initially set
* to address 12h (GPIOA) or 13h (GPIOB), the pointer will toggle between GPIOA and GPIOB. Note that the
* Address Pointer can initially point to either address in the register pair.
*/
public class MCP23017 extends MCP23x17 {
// Default I2C address
private static final int DEVICE_ADDRESS = 0x20;
private static final String DEVICE_NAME = "MCP23017";
private I2CDevice device;
public MCP23017() throws RuntimeIOException {
this(I2CConstants.BUS_1, DEVICE_ADDRESS, INTERRUPT_GPIO_NOT_SET, INTERRUPT_GPIO_NOT_SET);
}
public MCP23017(int interruptGpio) throws RuntimeIOException {
this(I2CConstants.BUS_1, DEVICE_ADDRESS, interruptGpio, interruptGpio);
}
public MCP23017(int interruptGpioA, int interruptGpioB) throws RuntimeIOException {
this(I2CConstants.BUS_1, DEVICE_ADDRESS, interruptGpioA, interruptGpioB);
}
public MCP23017(int controller, int address, int interruptGpio) throws RuntimeIOException {
this(controller, address, interruptGpio, interruptGpio);
}
public MCP23017(int controller, int address, int interruptGpioA, int interruptGpioB) throws RuntimeIOException {
super(DEVICE_NAME + "-" + controller + "-" + address, interruptGpioA, interruptGpioB);
device = new I2CDevice(controller, address, I2CConstants.ADDR_SIZE_7, I2CConstants.DEFAULT_CLOCK_FREQUENCY);
initialise();
}
@Override
public void close() throws RuntimeIOException {
super.close();
device.close();
}
@Override
protected void writeByte(int register, byte value) {
device.writeByte(register, value);
}
@Override
protected byte readByte(int register) {
return device.readByte(register);
}
}