updating adc examples

chp08/can/simpleCAN.c

@@ -0,0 +1,42 @@
+// From https://en.wikipedia.org/wiki/SocketCAN
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <net/if.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <linux/can.h>
+#include <linux/can/raw.h>
+
+int main(void) {
+	int s;
+	int nbytes;
+	struct sockaddr_can addr;
+	struct can_frame frame;
+	struct ifreq ifr;
+	const char *ifname = "can0";
+	if((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0) {
+		perror("Error while opening socket");
+		return -1;
+	}
+	strcpy(ifr.ifr_name, ifname);
+	ioctl(s, SIOCGIFINDEX, &ifr);
+	addr.can_family  = AF_CAN;
+	addr.can_ifindex = ifr.ifr_ifindex;
+	printf("%s at index %d\n", ifname, ifr.ifr_ifindex);
+	if(bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+		perror("Error in socket bind");
+		return -2;
+	}
+	frame.can_id  = 0x123;
+	frame.can_dlc = 3;
+	frame.data[0] = 0x11;
+	frame.data[1] = 0x22;
+        frame.data[2] = 0x33;
+	nbytes = write(s, &frame, sizeof(struct can_frame));
+	printf("Wrote %d bytes\n", nbytes);
+	return 0;
+}

chp09/simple/motor.c

@@ -0,0 +1,106 @@
+// This code comes from pololu.com directly
+// Uses POSIX functions to send and receive data from the virtual serial
+// port of a Pololu Simple Motor Controller.
+// NOTE: The Simple Motor Controller's Input Mode must be set to Serial/USB.
+// NOTE: You must change the 'const char * device' line below.
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <termios.h>
+#define SERIAL_ERROR -9999
+
+// Reads a variable from the SMC and returns it as number between 0 and 65535.
+// Returns SERIAL_ERROR if there was an error.
+// The 'variableId' argument must be one of IDs listed in the
+// "Controller Variables" section of the user's guide.
+// For variables that are actually signed, additional processing is required
+// (see smcGetTargetSpeed for an example).
+int smcGetVariable(int fd, unsigned char variableId) {
+  unsigned char command[] = {0xA1, variableId};
+  if(write(fd, &command, sizeof(command)) == -1)
+  {
+    perror("error writing");
+    return SERIAL_ERROR;
+  }
+  unsigned char response[2];
+  if(read(fd,response,2) != 2)
+  {
+    perror("error reading");
+    return SERIAL_ERROR;
+  }
+  return response[0] + 256*response[1];
+}
+
+// Returns the target speed (-3200 to 3200).
+// Returns SERIAL_ERROR if there is an error.
+int smcGetTargetSpeed(int fd) {
+  int val = smcGetVariable(fd, 20);
+  return val == SERIAL_ERROR ? SERIAL_ERROR : (signed short)val;
+}
+
+// Returns a number where each bit represents a different error, and the
+// bit is 1 if the error is currently active.
+// See the user's guide for definitions of the different error bits.
+// Returns SERIAL_ERROR if there is an error.
+int smcGetErrorStatus(int fd) {
+  return smcGetVariable(fd,0);
+}
+
+// Sends the Exit Safe Start command, which is required to drive the motor.
+// Returns 0 if successful, SERIAL_ERROR if there was an error sending.
+int smcExitSafeStart(int fd) {
+  const unsigned char command = 0x83;
+  if (write(fd, &command, 1) == -1)
+  {
+    perror("error writing");
+    return SERIAL_ERROR;
+  }
+  return 0;
+}
+
+// Sets the SMC's target speed (-3200 to 3200).
+// Returns 0 if successful, SERIAL_ERROR if there was an error sending.
+int smcSetTargetSpeed(int fd, int speed)
+{
+  unsigned char command[3];
+  if (speed < 0) {
+    command[0] = 0x86; // Motor Reverse
+    speed = -speed;
+  }
+  else {
+    command[0] = 0x85; // Motor Forward
+  }
+  command[1] = speed & 0x1F;
+  command[2] = speed >> 5 & 0x7F;
+  if (write(fd, command, sizeof(command)) == -1)
+  {
+    perror("error writing");
+    return SERIAL_ERROR;
+  }
+  return 0;
+}
+
+int main()
+{
+  printf("Starting the motor controller example\n");
+  const char * device = "/dev/ttyO4";  // Linux
+  int fd = open(device, O_RDWR | O_NOCTTY);
+  if (fd == -1) {
+    perror(device);
+    return 1;
+  }
+  struct termios options;
+  tcgetattr(fd, &options);
+  options.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+  options.c_oflag &= ~(ONLCR | OCRNL);
+  tcsetattr(fd, TCSANOW, &options);
+  smcExitSafeStart(fd);
+  printf("Error status: 0x%04x\n", smcGetErrorStatus(fd));
+  int speed = smcGetTargetSpeed(fd);
+  printf("Current Target Speed is %d.\n", speed);
+  int newSpeed = (speed <= 0) ? 3200 : -3200;
+  printf("Setting Target Speed to %d.\n", newSpeed);
+  smcSetTargetSpeed(fd, newSpeed);
+  close(fd);
+  return 0;
+}

chp09/stepper/StepperMotorApp.cpp

@@ -1,25 +1,22 @@
 /* A Stepper Motor Application
-* Written by Derek Molloy for the book "Exploring BeagleBone: Tools and 
-* Techniques for Building with Embedded Linux" by John Wiley & Sons, 2014
-* ISBN 9781118935125. Please see the file README.md in the repository root 
-* directory for copyright and GNU GPLv3 license information.
 * The pins for this example are wired as follows:
-* MS1 - BBB P8_12 = GPIO 1_12 = GPIO 44
-* MS2 - BBB P8_18 = GPIO 2_01 = GPIO 65
-* STEP- BBB P8_14 = GPIO 0_26 = GPIO 26
-* SLP - BBB P8_11 = GPIO 1_13 = GPIO 45
-* DIR - BBB P8_16 = GPIO 1_14 = GPIO 46
+* MS1 - GPIO 1_20 = GPIO 52
+* MS2 - GPIO 1_12 = GPIO 44
+* STEP- GPIO 2_00 = GPIO 64
+* SLP - GPIO 1_28 = GPIO 60
+* DIR - GPIO 1_14 = GPIO 46
 */
 
 #include <iostream>
+#include <unistd.h>
 #include "motor/StepperMotor.h"
 using namespace std;
 using namespace exploringBB;
 
 int main(){
    cout << "Starting EBB Stepper Motor Example:" << endl;
    //Using 5 GPIOs, RPM=60 and 200 steps per revolution
-   StepperMotor m(44,65,26,45,46,60,200);
+   StepperMotor m(52,44,64,60,46,60,200);
    m.setDirection(StepperMotor::ANTICLOCKWISE);
    m.setStepMode(StepperMotor::STEP_FULL);
    m.setSpeed(100);  //rpm

chp09/testADC/testADC.cpp

@@ -9,6 +9,7 @@
 #include<string>
 #include<sstream>
 #include<cmath>
+#include<unistd.h>
 using namespace std;
 
 #define LDR_PATH "/sys/bus/iio/devices/iio:device0/in_voltage"

chp09/tmp36/build

@@ -0,0 +1,2 @@
+#!/bin/bash
+g++ -o tmp36 tmp36.cpp bus/SPIDevice.cpp bus/BusDevice.cpp

chp09/tmp36/bus/BusDevice.cpp

@@ -0,0 +1,45 @@
+/*
+ * BusDevice.cpp  Created on: 23 May 2014
+ * Copyright (c) 2014 Derek Molloy (www.derekmolloy.ie)
+ * Made available for the book "Exploring BeagleBone"
+ * See: www.exploringbeaglebone.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 "BusDevice.h"
+
+namespace exploringBB {
+
+/**
+ * Constructor for a generic bus device
+ * @param bus the bus number
+ * @param device the device number
+ */
+BusDevice::BusDevice(unsigned int bus, unsigned int device) {
+	this->bus = bus;
+	this->device = device;
+	this->file=-1;
+}
+
+/**
+ * Destructor is unused
+ */
+BusDevice::~BusDevice() {}
+
+} /* namespace exploringBB */

chp09/tmp36/bus/BusDevice.h

@@ -0,0 +1,56 @@
+/*
+ * BusDevice.h  Created on: 23 May 2014
+ * Copyright (c) 2014 Derek Molloy (www.derekmolloy.ie)
+ * Made available for the book "Exploring BeagleBone"
+ * See: www.exploringbeaglebone.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 BUSDEVICE_H_
+#define BUSDEVICE_H_
+
+namespace exploringBB {
+
+/**
+ * @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.
+ */
+class BusDevice {
+protected:
+	unsigned int bus;    /**< the bus number */
+	unsigned int device; /**< the device number on the bus  */
+	int file;            /**< the file handle to the device */
+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 exploringBB */
+
+#endif /* BUSDEVICE_H_ */