MAXREFDES143#: DeepCover Embedded Security in IoT Authenticated Sensing & Notification

Dependencies:   MaximInterface mbed

The MAXREFDES143# is an Internet of Things (IoT) embedded security reference design, built to protect an industrial sensing node by means of authentication and notification to a web server. The hardware includes a peripheral module representing a protected sensor node monitoring operating temperature and remaining life of a filter (simulated through ambient light sensing) and an mbed shield representing a controller node responsible for monitoring one or more sensor nodes. The design is hierarchical with each controller node communicating data from connected sensor nodes to a web server that maintains a centralized log and dispatches notifications as necessary. The mbed shield contains a Wi-Fi module, a DS2465 coprocessor with 1-Wire® master function, an LCD, LEDs, and pushbuttons. The protected sensor node contains a DS28E15 authenticator, a DS7505 temperature sensor, and a MAX44009 light sensor. The mbed shield communicates to a web server by the onboard Wi-Fi module and to the protected sensor node with I2C and 1-Wire. The MAXREFDES143# is equipped with a standard shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The simplicity of this design enables rapid integration into any star-topology IoT network requiring the heightened security with low overhead provided by the SHA-256 symmetric-key algorithm.

More information about the MAXREFDES143# is available on the Maxim Integrated website.

Revision:
32:0a09505a656d
Parent:
17:41be4896ed6d
--- a/Display.cpp	Tue Apr 04 14:10:48 2017 -0500
+++ b/Display.cpp	Mon Nov 06 17:34:13 2017 -0600
@@ -28,63 +28,66 @@
 * trademarks, maskwork rights, or any other form of intellectual
 * property whatsoever. Maxim Integrated Products, Inc. retains all
 * ownership rights.
-*******************************************************************************
-*/
+*******************************************************************************/
 
 #include <sstream>
+#include <I2C.h>
+#include <wait_api.h>
 #include "Display.hpp"
-#include "I2C.h"
-#include "wait_api.h"
 
-//LCD Commands
-//If the RS bit is set to logic 1, these display bytes are stored in the display RAM at the address specified by the data pointer. The data pointer is
-//automatically updated and the data is directed to the intended ST7036i device. If the RS bit of the last control byte is set to
-//logic 0, these command bytes will be decoded and the setting of the device will be changed according to the received commands.
-enum LCD_Commands
-{
-  ControlByte = 0x00,	        //Only one control byte will be sent. Only a stream of data bytes is allowed to follow.
-  ControlByte_RS_Set = 0x40,  	//Only one control byte will be sent with the RS bit set. Only a stream of data bytes is allowed to follow.
-  ControlBytes = 0x80,          //Another control byte will follow, unless an I2C Stop condition is received.
-  ControlBytes_RS_Set = 0xC0, 	//RS Set and another control byte will follow, unless an I2C Stop condition is received.
+// LCD Commands
+// If the RS bit is set to logic 1, these display bytes are stored in the
+// display RAM at the address specified by the data pointer. The data pointer is
+// automatically updated and the data is directed to the intended ST7036i
+// device. If the RS bit of the last control byte is set to logic 0, these
+// command bytes will be decoded and the setting of the device will be changed
+// according to the received commands.
+enum LCD_Commands {
+  // Only one control byte will be sent.
+  // Only a stream of data bytes is allowed to follow.
+  ControlByte = 0x00,
+  // Only one control byte will be sent with the RS bit set.
+  // Only a stream of data bytes is allowed to follow.
+  ControlByte_RS_Set = 0x40,
+  // Another control byte will follow, unless an I2C Stop condition is received.
+  ControlBytes = 0x80, 
+  // RS Set and another control byte will follow, unless an I2C Stop condition
+  // is received.
+  ControlBytes_RS_Set =0xC0
 };
 
-//LCD Instructions
-enum LCD_Instructions
-{
+// LCD Instructions
+enum LCD_Instructions {
   ClearDisplay = 0x01,
-  Display_OFF = 0x08,     	//Display off
-  Display_ON = 0x0C,     	        //Display on, cursor off, cursor position off
+  Display_OFF = 0x08, // Display off
+  Display_ON = 0x0C,  // Display on, cursor off, cursor position off
   ReturnHome = 0x02,
   SetDdramAddress = 0x80
 };
 
 // LED Driver Port Registers
 // Initial port state 0x80
-enum LED_Driver_Ports
-{
+enum LED_Driver_Ports {
   P1 = 0x01,
-  P2 = 0x02,  // Blue LED
-  P3 = 0x03,  // Green LED
-  P4 = 0x04   // Red LED
+  P2 = 0x02, // Blue LED
+  P3 = 0x03, // Green LED
+  P4 = 0x04  // Red LED
 };
 
 // Convert a byte color value into the representation used by the MAX7306 PWM registers
-static uint8_t convertColorToPwmRegVal(uint8_t color)
-{
+static uint8_t convertColorToPwmRegVal(uint8_t color) {
   const uint8_t staticOffRegVal = 0x80; // LED is static off by setting to input
-  const uint8_t staticOnRegVal = 0x00; // LED is static on
-  const uint8_t minOnRegVal = 0x01; // LED on for minimum duty cycle
-  
+  const uint8_t staticOnRegVal = 0x00;  // LED is static on
+  const uint8_t minOnRegVal = 0x01;     // LED on for minimum duty cycle
+
   uint8_t regVal;
   if (color == 0x00) // Use static off for no color
   {
     regVal = staticOffRegVal;
-  }
-  else if (color == 0xFF) // Use static on for full color
+  } else if (color == 0xFF) // Use static on for full color
   {
     regVal = staticOnRegVal;
-  }
-  else // Use standard PWN for all other values
+  } else // Use standard PWN for all other values
   {
     // The 3 least significant bits cannot be rendered with the MAX7306
     regVal = color >> 3;
@@ -94,176 +97,164 @@
   return regVal;
 }
 
-Display::Display(mbed::I2C & I2C_intf, uint8_t LCD_I2C_addr, uint8_t LED_driver_I2C_addr)
-  : m_I2C_intf(I2C_intf), m_LCD_I2C_addr(LCD_I2C_addr), m_LED_driver_I2C_addr(LED_driver_I2C_addr)
-{
-  
-}
+Display::Display(mbed::I2C & I2C_intf, uint8_t LCD_I2C_addr,
+                 uint8_t LED_driver_I2C_addr)
+    : m_I2C_intf(I2C_intf), m_LCD_I2C_addr(LCD_I2C_addr),
+      m_LED_driver_I2C_addr(LED_driver_I2C_addr) {}
 
-void Display::initialize(void)
-{
+void Display::initialize() {
   initializeLCD();
   initializeLED_Driver();
 }
 
-void Display::initializeLED_Driver(void)
-{
-  const uint8_t Configuration26 = 0x26;  //intial port state 0xEC
-  const uint8_t Configuration27 = 0x27;  //intial port state 0x8F
-  
-  //Intial mode
-  //write to Configuration Register 0x26
+void Display::initializeLED_Driver() {
+  const uint8_t Configuration26 = 0x26; // Intial port state 0xEC
+  const uint8_t Configuration27 = 0x27; // Intial port state 0x8F
+
+  // Intial mode
+  // Write to Configuration Register 0x26
   m_I2C_intf.start();
   m_I2C_intf.write(m_LED_driver_I2C_addr);
   m_I2C_intf.write(Configuration26);
-  //RST does  reset PWM/blink counters, RST resets registers to power-on-reset state
-  m_I2C_intf.write(0x1F); 
+  // RST resets registers to power-on-reset state
+  // RST does reset PWM/blink counters, 
+  m_I2C_intf.write(0x1F);
   m_I2C_intf.stop();
-  
-  //Write to Configuration Register 0x27
+
+  // Write to Configuration Register 0x27
   m_I2C_intf.start();
   m_I2C_intf.write(m_LED_driver_I2C_addr);
   m_I2C_intf.write(Configuration27);
-  //Enable bus time out, set P1,P2,P3 to be controlled by their registers (0x01,0x02,0x03)
-  m_I2C_intf.write(0x0E); 
+  // Enable bus time out, and set P1, P2, P3 to be controlled by their registers
+  // (0x01, 0x02, 0x03)
+  m_I2C_intf.write(0x0E);
   m_I2C_intf.stop();
 }
 
-void Display::setBackLightColor(const Color & color)
-{  
+void Display::setBackLightColor(const Color & color) {
   // Red
   m_I2C_intf.start();
   m_I2C_intf.write(m_LED_driver_I2C_addr);
   m_I2C_intf.write(P4);
-  m_I2C_intf.write(convertColorToPwmRegVal(color.R)); 
+  m_I2C_intf.write(convertColorToPwmRegVal(color.R));
   m_I2C_intf.stop();
-   
+
   // Green
   m_I2C_intf.start();
   m_I2C_intf.write(m_LED_driver_I2C_addr);
   m_I2C_intf.write(P3);
-  m_I2C_intf.write(convertColorToPwmRegVal(color.G)); 
+  m_I2C_intf.write(convertColorToPwmRegVal(color.G));
   m_I2C_intf.stop();
-  
+
   // Blue
   m_I2C_intf.start();
   m_I2C_intf.write(m_LED_driver_I2C_addr);
   m_I2C_intf.write(P2);
-  m_I2C_intf.write(convertColorToPwmRegVal(color.B)); 
+  m_I2C_intf.write(convertColorToPwmRegVal(color.B));
   m_I2C_intf.stop();
 }
 
-void Display::clearLine(Line line)
-{
+void Display::clearLine(Line line) {
   writeCompleteLine("", line);
   setCursorPosition(line);
 }
 
-void Display::clearDisplay(void)
-{
+void Display::clearDisplay() {
   m_I2C_intf.start();
   m_I2C_intf.write(m_LCD_I2C_addr);
-  m_I2C_intf.write(ControlByte);     //No more control bytes will be sent
+  m_I2C_intf.write(ControlByte); //No more control bytes will be sent
   m_I2C_intf.write(ClearDisplay);
   m_I2C_intf.stop();
 }
 
-void Display::initializeLCD(void)
-{
+void Display::initializeLCD() {
   m_I2C_intf.start();
   m_I2C_intf.write(m_LCD_I2C_addr);
-  m_I2C_intf.write(ControlByte);    //No more control bytes will be sent
-  m_I2C_intf.write(0x38);               //Function Set IS[2:1] = 0,0 (&h38 = Single height font, 0x3C = double height font)
-  m_I2C_intf.write(0x39);               //Function Set IS[2:1] = (0,1)
-  //When IS[2:1]=(0,0): normal instruction be selected(refer instruction table 0)
-  //When IS[2:1]=(0,1): extension instruction be selected(refer instruction table 1 )
-  //When IS[2:1]=(1,0): extension instruction be selected(refer instruction table 2 )
-  m_I2C_intf.write(0x14);               //BIAS SET
-  m_I2C_intf.write(0x70);               //CONTRAST (was 0x78)
-  m_I2C_intf.write(0x5E);               //POWER/ICON CONTROL/CONTRAST (upper two bits)
-  m_I2C_intf.write(0x6D);               //FOLLOWER CONTROL
+  m_I2C_intf.write(ControlByte); // No more control bytes will be sent
+  // Function Set IS[2:1] = 0,0 (&h38 = Single height font, 0x3C = double height font)
+  m_I2C_intf.write(0x38);
+  m_I2C_intf.write(0x39); //Function Set IS[2:1] = (0,1)
+  // When IS[2:1]=(0,0): normal instruction be selected(refer instruction table 0)
+  // When IS[2:1]=(0,1): extension instruction be selected(refer instruction table 1)
+  // When IS[2:1]=(1,0): extension instruction be selected(refer instruction table 2)
+  m_I2C_intf.write(0x14); // BIAS SET
+  m_I2C_intf.write(0x70); // CONTRAST (was 0x78)
+  m_I2C_intf.write(0x5E); // POWER/ICON CONTROL/CONTRAST (upper two bits)
+  m_I2C_intf.write(0x6D); // FOLLOWER CONTROL
   m_I2C_intf.stop();
-  wait_ms(200);                         //Wait for power stable
+  wait_ms(200); // Wait for power stable
   m_I2C_intf.start();
   m_I2C_intf.write(m_LCD_I2C_addr);
-  m_I2C_intf.write(ControlByte);        //No more control bytes will be sent
-  m_I2C_intf.write(Display_ON);         //Display on, cursor on, cursor position on
-  m_I2C_intf.write(ClearDisplay);       //Clear Display
-  m_I2C_intf.write(0x06);               //ENTRY MODE
+  m_I2C_intf.write(ControlByte);  // No more control bytes will be sent
+  m_I2C_intf.write(Display_ON);   // Display on, cursor on, cursor position on
+  m_I2C_intf.write(ClearDisplay); // Clear Display
+  m_I2C_intf.write(0x06);         // ENTRY MODE
   m_I2C_intf.stop();
 }
 
-void Display::writeCharacter(uint8_t character)
-{
+void Display::writeCharacter(uint8_t character) {
   m_I2C_intf.start();
   m_I2C_intf.write(m_LCD_I2C_addr);
-  m_I2C_intf.write(ControlByte_RS_Set);	//No more control bytes will be sent
-  m_I2C_intf.write(character);	        //Display on, cursor on, cursor position on
-  m_I2C_intf.stop();	
+  m_I2C_intf.write(ControlByte_RS_Set); // No more control bytes will be sent
+  m_I2C_intf.write(character); // Display on, cursor on, cursor position on
+  m_I2C_intf.stop();
 }
 
-void Display::writeText(const std::string & text)
-{
+void Display::writeText(const std::string & text) {
   const char RETURN_CHAR = 0x16;
-  
+
   size_t length = text.length();
   if (length > lineLength)
     length = lineLength;
-  
+
   //Write to LCD
   m_I2C_intf.start();
   m_I2C_intf.write(m_LCD_I2C_addr);
   m_I2C_intf.write(ControlByte_RS_Set);
-  
-  for(size_t i = 0; i < length; i++)
-  {
-    if(text[i] != RETURN_CHAR)
+
+  for (size_t i = 0; i < length; i++) {
+    if (text[i] != RETURN_CHAR)
       m_I2C_intf.write(text[i]);
   }
-  
+
   m_I2C_intf.stop();
 }
 
-void Display::setCursorPosition(Line line, size_t position)
-{  
-  if (position > (lineLength - 1)) // Set to last line character for values outside the upper bound
+void Display::setCursorPosition(Line line, size_t position) {
+  // Set to last line character for values outside the upper bound
+  if (position > (lineLength - 1))
     position = (lineLength - 1);
 
   m_I2C_intf.start();
   m_I2C_intf.write(m_LCD_I2C_addr);
   m_I2C_intf.write(ControlByte); // No more control bytes will be sent
-  if(line == SecondLine) // Offset for second line
+  if (line == SecondLine)        // Offset for second line
     position += 0x40;
   m_I2C_intf.write(SetDdramAddress | position);
   m_I2C_intf.stop();
 }
 
-void Display::writeLine(const std::string & text, Line line)
-{  
+void Display::writeLine(const std::string & text, Line line) {
   setCursorPosition(line);
   writeText(text);
 }
 
-void Display::writeCompleteLine(const std::string & text, Line line)
-{
+void Display::writeCompleteLine(const std::string & text, Line line) {
   // Add padding to user's string
   std::string writeText(text);
   if (writeText.length() < lineLength)
     writeText.append(lineLength - writeText.length(), ' ');
-  
+
   writeLine(writeText, line);
 }
 
-void Display::writeMessage(const std::string & message)
-{
-  if (message.length() > lineLength)
-  {
+void Display::writeMessage(const std::string & message) {
+  if (message.length() > lineLength) {
     // Find split point
     std::istringstream messageStream(message);
     std::string word;
     size_t splitIndex = 0;
-    do
-    {
+    do {
       if (word.length() > 0)
         splitIndex += (word.length() + 1);
       std::getline(messageStream, word, ' ');
@@ -272,15 +263,11 @@
     {
       writeCompleteLine(message.substr(0, lineLength), FirstLine);
       writeCompleteLine(message.substr(lineLength), SecondLine);
-    }
-    else
-    {
+    } else {
       writeCompleteLine(message.substr(0, splitIndex - 1), FirstLine);
       writeCompleteLine(message.substr(splitIndex), SecondLine);
     }
-  }
-  else
-  {
+  } else {
     writeCompleteLine(message, FirstLine);
     writeCompleteLine("", SecondLine);
   }