fixing directory tree

chp10/gpioExpander/build

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+#!/bin/bash
+g++ -o example example.cpp gpioExpander.cpp bus/SPIDevice.cpp bus/I2CDevice.cpp bus/BusDevice.cpp
+g++ -Wall -o testSPI testSPI.cpp bus/SPIDevice.cpp bus/I2CDevice.cpp bus/BusDevice.cpp
+g++ -o testI2C testI2C.cpp bus/I2CDevice.cpp bus/BusDevice.cpp
+g++ -o display displayRegisters.cpp gpioExpander.cpp bus/I2CDevice.cpp bus/SPIDevice.cpp bus/BusDevice.cpp

chp10/gpioExpander/bus/BusDevice.cpp

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+/*
+ * BusDevice.cpp  Created on: 23 May 2014
+ * Copyright (c) 2014 Derek Molloy (www.derekmolloy.ie)
+ * Made available for the book "Exploring Raspberry Pi"
+ */
+
+#include "BusDevice.h"
+
+namespace exploringRPi {
+
+BusDevice::BusDevice(unsigned int bus, unsigned int device) {
+	this->bus = bus;
+	this->device = device;
+	this->file=-1;
+}
+
+BusDevice::~BusDevice() {}
+
+} /* namespace exploringRPi */

chp10/gpioExpander/bus/BusDevice.h

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+/*
+ * BusDevice.h  Created on: 23 May 2015
+ * Copyright (c) 2014 Derek Molloy (www.derekmolloy.ie)
+ * Made available for the book "Exploring Raspberry Pi"
+ */
+
+#ifndef BUSDEVICE_H_
+#define BUSDEVICE_H_
+
+namespace exploringRPi {
+
+/**
+ * @class BusDevice
+ * @brief This class is the parent of I2C and SPI devices, so that devices that use both
+ * SPI and I2C interfaces can use those interfaces interchangeably. Because it contains
+ * abstract methods, the child classes MUST implement the methods that are listed in this
+ * class. This means that the
+ */
+class BusDevice {
+protected:
+	unsigned int bus;
+	unsigned int device;
+	int file;
+public:
+	BusDevice(unsigned int bus, unsigned int device);
+	virtual int open()=0;
+	virtual unsigned char readRegister(unsigned int registerAddress)=0;
+	virtual unsigned char* readRegisters(unsigned int number, unsigned int fromAddress=0)=0;
+	virtual int write(unsigned char value)=0;
+	virtual int writeRegister(unsigned int registerAddress, unsigned char value)=0;
+	virtual void debugDumpRegisters(unsigned int number = 0xff)=0;
+	virtual void close()=0;
+	virtual ~BusDevice();
+};
+
+} /* namespace exploringRPi */
+
+#endif /* BUSDEVICE_H_ */

chp10/gpioExpander/bus/I2CDevice.cpp

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+/*
+ * I2C.cpp  Created on: 17 May 2015
+ * Copyright (c) 2015 Derek Molloy (www.derekmolloy.ie)
+ * Made available for the book "Exploring Raspberry Pi"
+ * See: www.exploringrpi.com
+ * Licensed under the EUPL V.1.1
+ *
+ * This Software is provided to You under the terms of the European 
+ * Union Public License (the "EUPL") version 1.1 as published by the 
+ * European Union. Any use of this Software, other than as authorized 
+ * under this License is strictly prohibited (to the extent such use 
+ * is covered by a right of the copyright holder of this Software).
+ * 
+ * This Software is provided under the License on an "AS IS" basis and 
+ * without warranties of any kind concerning the Software, including 
+ * without limitation merchantability, fitness for a particular purpose, 
+ * absence of defects or errors, accuracy, and non-infringement of 
+ * intellectual property rights other than copyright. This disclaimer 
+ * of warranty is an essential part of the License and a condition for 
+ * the grant of any rights to this Software.
+ * 
+ * For more details, see http://www.derekmolloy.ie/
+ */
+
+#include"I2CDevice.h"
+#include<iostream>
+#include<sstream>
+#include<fcntl.h>
+#include<iomanip>
+#include<stdio.h>
+#include<unistd.h>
+#include<sys/ioctl.h>
+#include<linux/i2c.h>
+#include<linux/i2c-dev.h>
+using namespace std;
+
+#define HEX(x) setw(2) << setfill('0') << hex << (int)(x)
+
+namespace exploringRPi {
+
+/**
+ * Constructor for the I2CDevice class. It requires the bus number and device number. The constructor
+ * opens a file handle to the I2C device, which is destroyed when the destructor is called
+ * @param bus The bus number. Usually 0 or 1 on the RPi
+ * @param device The device ID on the bus.
+ */
+I2CDevice::I2CDevice(unsigned int bus, unsigned int device):
+	BusDevice(bus,device){
+	this->open();
+}
+
+/**
+ * Open a connection to an I2C device
+ * @return 1 on failure to open to the bus or device, 0 on success.
+ */
+int I2CDevice::open(){
+   string name;
+   if(this->bus==0) name = RPI_I2C_0;
+   else name = RPI_I2C_1;
+
+   if((this->file=::open(name.c_str(), O_RDWR)) < 0){
+      perror("I2C: failed to open the bus\n");
+	  return 1;
+   }
+   if(ioctl(this->file, I2C_SLAVE, this->device) < 0){
+      perror("I2C: Failed to connect to the device\n");
+	  return 1;
+   }
+   return 0;
+}
+
+/**
+ * Write a single byte value to a single register.
+ * @param registerAddress The register address
+ * @param value The value to be written to the register
+ * @return 1 on failure to write, 0 on success.
+ */
+
+int I2CDevice::writeRegister(unsigned int registerAddress, unsigned char value){
+   unsigned char buffer[2];
+   buffer[0] = registerAddress;
+   buffer[1] = value;
+   if(::write(this->file, buffer, 2)!=2){
+      perror("I2C: Failed write to the device\n");
+      return 1;
+   }
+   return 0;
+}
+
+/**
+ * Write a single value to the I2C device. Used to set up the device to read from a
+ * particular address.
+ * @param value the value to write to the device
+ * @return 1 on failure to write, 0 on success.
+ */
+int I2CDevice::write(unsigned char value){
+   unsigned char buffer[1];
+   buffer[0]=value;
+   if (::write(this->file, buffer, 1)!=1){
+      perror("I2C: Failed to write to the device\n");
+      return 1;
+   }
+   return 0;
+}
+
+/**
+ * Read a single register value from the address on the device.
+ * @param registerAddress the address to read from
+ * @return the byte value at the register address.
+ */
+unsigned char I2CDevice::readRegister(unsigned int registerAddress){
+   this->write(registerAddress);
+   unsigned char buffer[1];
+   if(::read(this->file, buffer, 1)!=1){
+      perror("I2C: Failed to read in the value.\n");
+      return 1;
+   }
+   return buffer[0];
+}
+
+/**
+ * Method to read a number of registers from a single device. This is much more efficient than
+ * reading the registers individually. The from address is the starting address to read from, which
+ * defaults to 0x00.
+ * @param number the number of registers to read from the device
+ * @param fromAddress the starting address to read from
+ * @return a pointer of type unsigned char* that points to the first element in the block of registers
+ */
+unsigned char* I2CDevice::readRegisters(unsigned int number, unsigned int fromAddress){
+	this->write(fromAddress);
+	unsigned char* data = new unsigned char[number];
+    if(::read(this->file, data, number)!=(int)number){
+       perror("IC2: Failed to read in the full buffer.\n");
+	   return NULL;
+    }
+	return data;
+}
+
+/**
+ * Method to dump the registers to the standard output. It inserts a return character after every
+ * 16 values and displays the results in hexadecimal to give a standard output using the HEX() macro
+ * that is defined at the top of this file. The standard output will stay in hexadecimal format, hence
+ * the call on the last like.
+ * @param number the total number of registers to dump, defaults to 0xff
+ */
+
+void I2CDevice::debugDumpRegisters(unsigned int number){
+	cout << "Dumping Registers for Debug Purposes:" << endl;
+	unsigned char *registers = this->readRegisters(number);
+	for(int i=0; i<(int)number; i++){
+		cout << HEX(*(registers+i)) << " ";
+		if (i%16==15) cout << endl;
+	}
+	cout << dec;
+}
+
+/**
+ * Close the file handles and sets a temporary state to -1.
+ */
+void I2CDevice::close(){
+	::close(this->file);
+	this->file = -1;
+}
+
+/**
+ * Closes the file on destruction, provided that it has not already been closed.
+ */
+I2CDevice::~I2CDevice() {
+	if(file!=-1) this->close();
+}
+
+} /* namespace exploringRPi */

chp10/gpioExpander/bus/I2CDevice.h

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+/*
+ * I2C.h  Created on: 17 May 2015
+ * Copyright (c) 2015 Derek Molloy (www.derekmolloy.ie)
+ * Made available for the book "Exploring Raspberry Pi"
+ * See: www.exploringrpi.com
+ * Licensed under the EUPL V.1.1
+ *
+ * This Software is provided to You under the terms of the European 
+ * Union Public License (the "EUPL") version 1.1 as published by the 
+ * European Union. Any use of this Software, other than as authorized 
+ * under this License is strictly prohibited (to the extent such use 
+ * is covered by a right of the copyright holder of this Software).
+ * 
+ * This Software is provided under the License on an "AS IS" basis and 
+ * without warranties of any kind concerning the Software, including 
+ * without limitation merchantability, fitness for a particular purpose, 
+ * absence of defects or errors, accuracy, and non-infringement of 
+ * intellectual property rights other than copyright. This disclaimer 
+ * of warranty is an essential part of the License and a condition for 
+ * the grant of any rights to this Software.
+ * 
+ * For more details, see http://www.derekmolloy.ie/
+ */
+
+#ifndef I2C_H_
+#define I2C_H_
+#include"BusDevice.h"
+
+#define RPI_I2C_0 "/dev/i2c-0"
+#define RPI_I2C_1 "/dev/i2c-1"
+
+namespace exploringRPi{
+
+/**
+ * @class I2CDevice
+ * @brief Generic I2C Device class that can be used to connect to any type of I2C device and read or write to its registers
+ */
+class I2CDevice:public BusDevice{
+
+public:
+	I2CDevice(unsigned int bus, unsigned int device);
+	virtual int open();
+	virtual int write(unsigned char value);
+	virtual unsigned char readRegister(unsigned int registerAddress);
+	virtual unsigned char* readRegisters(unsigned int number, unsigned int fromAddress=0);
+	virtual int writeRegister(unsigned int registerAddress, unsigned char value);
+	virtual void debugDumpRegisters(unsigned int number = 0xff);
+	virtual void close();
+	virtual ~I2CDevice();
+};
+
+} /* namespace exploringRPi */
+
+#endif /* I2C_H_ */