Diff: main.cpp

Revision:

0:e72ea6decc70

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri May 22 11:45:19 2015 +0000
@@ -0,0 +1,2165 @@
+/* Main application file for the device side of the
+ * MWC demo 2015.
+ *
+ * Copyright (C) u-blox Melbourn Ltd
+ * u-blox Melbourn Ltd, Melbourn, UK
+ *
+ * All rights reserved.
+ *
+ * This source file is the sole property of u-blox Melbourn Ltd.
+ * Reproduction or utilization of this source in whole or part is
+ * forbidden without the written consent of u-blox Melbourn Ltd.
+ */
+
+#include "mbed.h"
+#include "IapApi.h"
+#include "MDM.h"
+#include "IotMeterApi.hpp"
+#include "WaterMeterApi.hpp"
+
+#define FILE_REV "Revision 1.0"
+#define FILE_CL  "Pushed by RobMeades"
+#define FILE_DATETIME "2015/05/15"
+
+// ----------------------------------------------------------------
+// GENERAL COMPILE-TIME CONSTANTS
+// ----------------------------------------------------------------
+
+// The time for which the flash turns the LED on or off for
+#define FLASH_DURATION_MS 250
+
+// The maximum number of datagrams that are available for use
+// at any one time (i.e. the total of send and receive)
+#define MAX_NUM_DATAGRAMS 10
+
+// The number of milliseconds to wait for a received message
+// after a send
+#define RECEIVE_DURATION_MS 1000
+
+// The number of seconds to wait for device registration
+#define WAIT_REG_S 300
+
+// The number of SOS flashes at an assert before restarting
+// if not in development mode; in development mode there
+// is no restart, just flashing forever
+#define NUM_ASSERT_SOS_BEFORE_RESTART 3
+
+// Baud rate of the PC interface
+//#define PC_BAUD_RATE 9600
+#define PC_BAUD_RATE 9600
+
+// The maximum length of a MACTEST string (as raw bytes)
+#define MACTEST_STRING_MAX_SIZE 48
+
+// The time to wait for a user to interrupt to change
+// the mactest string
+#define USER_WAIT_DECISECONDS 50
+
+// The size of the stack required by IAP
+#define SIZE_STACK_FOR_IAP 32
+
+// An ID for the NVRAM contents so that we
+// can tell if it's there.
+#define NVRAM_ID 0x12345678
+
+// NVRAM bytes to write (can be a set of fixed sizes, min 256)
+#define NVRAM_SIZE 256
+
+// Macro to convert to upper case
+#define TO_UPPER(x) (((x) >= 'a' && (x) <= 'z') ? x & ~0x20 : x)
+
+// Macro to tell is something is odd
+#define IS_ODD(x) (((x) & 0x01) == 0x01 ? true : false)
+
+// Macro to tell is something is even
+#define IS_EVEN(x) (((x) & 0x01) == 0x01 ? false : true)
+
+// Highlight for talking to the user at the PC side
+#define COLOUR_HIGHLIGHT "\033[33m"
+
+// Default colour
+#define COLOUR_DEFAULT "\033[39m"
+
+// ----------------------------------------------------------------
+// TYPES
+// ----------------------------------------------------------------
+
+/// A type to hold a datagram
+// Used for encoding AT commands on the send side and
+// receiving messages on the receive side.
+typedef struct DatagramTag_t
+{
+    uint32_t size;
+    char pBody[MAX_DATAGRAM_SIZE_RAW];
+} Datagram_t;
+
+/// A linked list entry holding a datagram
+typedef struct DatagramEntryTag_t
+{
+    bool inUse;
+    Datagram_t datagram;
+    DatagramEntryTag_t * pPrevEntry;
+    DatagramEntryTag_t * pNextEntry;
+
+} DatagramEntry_t;
+
+/// Debug flashes
+typedef enum DebugSosTypeTag_t
+{
+    DEBUG_SOS_WATER_METER_PROBLEM = WAKE_UP_CODE_WATER_METER_PROBLEM,
+    DEBUG_SOS_AT_COMMAND_PROBLEM = WAKE_UP_CODE_AT_COMMAND_PROBLEM,
+    DEBUG_SOS_NETWORK_SEND_PROBLEM = WAKE_UP_CODE_NETWORK_SEND_PROBLEM,
+    DEBUG_SOS_MEMORY_ALLOC_PROBLEM = WAKE_UP_CODE_MEMORY_ALLOC_PROBLEM,
+    DEBUG_SOS_PROTOCOL_PROBLEM = WAKE_UP_CODE_PROTOCOL_PROBLEM,
+    DEBUG_SOS_GENERIC_FAILURE = WAKE_UP_CODE_GENERIC_FAILURE,
+    DEBUG_SOS_REBOOT = WAKE_UP_CODE_REBOOT,
+} DebugSosType_t;
+
+/// Context data, which will be in NVRAM
+// and must be no bigger than NVRAM_SIZE
+typedef struct NvContextTag_t
+{
+    uint32_t id;                             //<! An ID for the NVRAM
+    bool devModeOnNotOff;                    //<! Development mode
+    WakeUpCode_t wakeUpCode;                 //<! Wake-up code
+    uint32_t readingIntervalSeconds;         //<! The read interval
+    bool ledOnNotOff;                        //<! The LED state
+    bool flashOnNotOff;                      //<! The Flash state
+    char mactestString[MACTEST_STRING_MAX_SIZE]; //<! The MACTEST string, only used with phase 1 modules
+                                             //<! this is a string of bytes (so NOT the hex coded form)
+                                             //<! and no terminator is stored
+    uint32_t mactestStringSize;              //<! The size of the MACTEST string
+} NvContext_t;
+
+
+typedef union NvramTag_t
+{
+    char rawBytes[NVRAM_SIZE];
+    NvContext_t nvContext;
+} Nvram_t;
+
+// Note that order is important below: modules of newer phases
+// should be of higher values
+typedef enum ModulePhase_t
+{
+    MODULE_PHASE_UNKNOWN,
+    MODULE_PHASE_1,     //<! As used at Mobile World Congress Barcelona 2015
+    MODULE_PHASE_2,    //<! As used at Mobile World Congress Shanghai 2015
+    MODULE_PHASE_3
+} ModulePhase;
+
+// ----------------------------------------------------------------
+// PRIVATE VARIABLES
+// ----------------------------------------------------------------
+
+// Non-volatile storage area, aligned on a 4-byte boundary
+Nvram_t  __attribute__((aligned(4))) nvram;
+
+// Instantiate the NVRAM handling code
+static IAP iap;
+
+// Pointer to instance of the Neul modem, populated once we
+// get into main() as its constructor requires some initialisation
+// that is only complete on entry into main()
+MDMSerial *pgNeul = NULL;
+
+// Instantiate the interface to the water meter
+static WaterMeterHandler gWaterMeter;
+
+// Instantiate the messaging API to the C027N
+// as an IoT metering device
+static MessageCodec gMessageCodec;
+
+// The module phase
+static ModulePhase gModulePhase = MODULE_PHASE_UNKNOWN;
+
+// A good default MACTEST string
+static char defaultMactestString[] = {0x02, 0x00, 0x00, 0x00, 0x60, 0xb3, 0xc8, 0x37, 0x20, 0x0e, 0x1a, 0x35, 0x16, 0x00, 0x00, 0x00, 0x45, 0x23, 0x01, 0x00, 0x01, 0x02, 0x01, 0x00};
+
+// The LED
+static DigitalOut led(LED);
+static const int gpioTable[] = {D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13};
+
+// The connected GPIO(s)
+static DigitalOut pump((PinName) gpioTable[GPIO_WATER_PUMP]);
+
+// Head of free datagram linked list
+static DatagramEntry_t gFreeDatagramListHeadUnused;
+// Head of send datagram linked list
+static DatagramEntry_t gSendDatagramListHead;
+// Head of receive datagram linked list
+static DatagramEntry_t gRecvDatagramListHead;
+
+const char hexTable[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', \
+                         '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+
+// ----------------------------------------------------------------
+// GENERIC PRIVATE FUNCTION PROTOTYPES
+// ----------------------------------------------------------------
+
+static void doDebugFlash (uint32_t numberOfFlashes);
+static void debugSos(DebugSosType_t debugSosType);
+#ifdef DEBUG
+  static void debugPrintLists (void);
+#endif
+static void getModulePhase (void);
+static bool isValidHex (char digit);
+static uint8_t hexToNibble (char digit);
+static uint8_t hexTobyte (char digit1, char digit2);
+static char peekChar (void);
+static char getChar (void);
+static uint32_t getUserHexString (uint32_t size, char * buf);
+static void printByteString (uint32_t size, const char * buf);
+static void printMactestString (uint32_t size, const char * string);
+static void configureModule (void);
+static void assert (bool condition, DebugSosType_t debugSosType, const char * pFormat, ...);
+static void assertAlways (DebugSosType_t debugSosType, const char * pFormat, ...);
+static bool writeNvContext (Nvram_t * pNvram);
+static NvContext_t * resetNvContext (void);
+static NvContext_t * readNvContext (void);
+static void doSendFlash (void);
+static void doRecvFlash (void);
+static bool setGpio (GpioState_t * pGpioState);
+static bool getGpio (GpioState_t * pGpioState);
+static void setWakeUpCode (WakeUpCode_t wakeUpCode);
+static void setDevMode (bool onNotOff);
+static void setReadingIntervalSeconds (uint32_t readingIntervalSeconds);
+static void setLed (bool onNotOff);
+static void setFlash (bool onNotOff);
+static bool init (void);
+static void deInit (void);
+static Datagram_t * allocDatagram (DatagramEntry_t * pDatagramListHead);
+static Datagram_t * allocSendDatagram (void);
+static Datagram_t * allocRecvDatagram (void);
+static void freeDatagram (Datagram_t *pDatagram, DatagramEntry_t * pDatagramListHead);
+static void freeRecvDatagram (Datagram_t *pDatagram);
+static void freeAllDatagrams (DatagramEntry_t *pDatagramListHead);
+static void freeUnusedDatagrams (DatagramEntry_t *pDatagramListHead);
+static void freeUnusedSendDatagrams (void);
+static void freeUnusedRecvDatagrams (void);
+static bool waitReg (uint32_t durationSeconds);
+static bool sendAndReceive (void);
+static bool queueInitialDatagram (void);
+static bool queuePeriodicDatagram (void);
+static bool handleSerialNumberGetReqDlMsg (void);
+static bool handleRebootReqDlMsg (bool devModeOnNotOff);
+static bool enqueueReadingIntervalSetGetCnfUlMsg (bool setNotGet);
+static bool handleReadingIntervalSetReqDlMsg (uint32_t readingIntervalSeconds);
+static bool handleReadingIntervalGetReqDlMsg (void);
+static bool enqueueGpioSetGetCnfUlMsg (bool setNotGet, GpioState_t * gpioState);
+static bool handleGpioSetReqDlMsg (GpioState_t * pGpioState);
+static bool handleGpioGetReqDlMsg (uint8_t gpio);
+static bool enqueueLedSetGetCnfUlMsg (bool setNotGet);
+static bool handleLedSetReqDlMsg (bool onNotOff);
+static bool handleLedGetReqDlMsg (void);
+static bool enqueueFlashSetGetCnfUlMsg (bool setNotGet);
+static bool handleFlashSetReqDlMsg (bool onNotOff);
+static bool handleFlashGetReqDlMsg (void);
+static bool processReceivedDatagrams (void);
+static MDMSerial *getMDMSerial(void);
+
+// ----------------------------------------------------------------
+// GENERIC PRIVATE FUNCTIONS
+// ----------------------------------------------------------------
+
+// Debug
+static void doDebugFlash (uint32_t numberOfFlashes)
+{
+    uint32_t x;
+    uint32_t y;
+    bool devModeOnNotOff = readNvContext()->devModeOnNotOff;
+
+    led = 0;
+    wait_ms (1000);
+    for (y = 0; (y < NUM_ASSERT_SOS_BEFORE_RESTART) | devModeOnNotOff; y++)
+    {
+        for (x = 0; x < numberOfFlashes; x++)
+        {
+            led = !led;
+            wait_ms (FLASH_DURATION_MS);
+            led = !led;
+            wait_ms (FLASH_DURATION_MS);
+        }
+        wait_ms (2000);
+    }
+
+    // Restart the system and try again
+    printf ("Resetting system...\n");
+    wait_ms (2000);
+    NVIC_SystemReset();
+
+}
+
+static void debugSos(DebugSosType_t debugSosType)
+{
+    switch (debugSosType)
+    {
+        case (DEBUG_SOS_WATER_METER_PROBLEM):
+        {
+            doDebugFlash (3);
+        }
+        break;
+        case (DEBUG_SOS_AT_COMMAND_PROBLEM):
+        {
+            doDebugFlash (4);
+        }
+        break;
+        case (DEBUG_SOS_NETWORK_SEND_PROBLEM):
+        {
+            doDebugFlash (5);
+        }
+        break;
+        case (DEBUG_SOS_MEMORY_ALLOC_PROBLEM):
+        {
+            doDebugFlash (6);
+        }
+        break;
+        case (DEBUG_SOS_PROTOCOL_PROBLEM):
+        {
+            doDebugFlash (7);
+        }
+        break;
+        case (DEBUG_SOS_GENERIC_FAILURE):
+        {
+            doDebugFlash (8);
+        }
+        break;
+        case (DEBUG_SOS_REBOOT):
+        {
+            doDebugFlash (9);
+        }
+        break;
+        default:
+        {
+            doDebugFlash (10);
+        }
+        break;
+    }
+}
+
+/// Print out the datagram lists for debugging
+#ifdef DEBUG
+static void debugPrintLists (void)
+{
+    uint32_t x;
+    DatagramEntry_t * pEntry;
+
+    printf ("LIST CONTENTS:\n");
+
+    printf ("Free list head is at 0x%ld.\n", &gFreeDatagramListHeadUnused);
+    pEntry = &gFreeDatagramListHeadUnused;
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        printf (" %d: prev 0x%lx, next 0x%lx, inUse 0x%x, datagram.size %d, datagram \"%s\".\n",
+                x, pEntry->pPrevEntry, pEntry->pNextEntry, pEntry->inUse, pEntry->datagram.size, pEntry->datagram.pBody);
+        pEntry = pEntry->pNextEntry;
+    }
+
+    printf ("Send list head is at 0x%ld.\n", &gSendDatagramListHead);
+    pEntry = &gSendDatagramListHead;
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        printf (" %d: prev 0x%lx, next 0x%lx, inUse 0x%x, datagram.size %d, datagram \"%s\".\n",
+                x, pEntry->pPrevEntry, pEntry->pNextEntry, pEntry->inUse, pEntry->datagram.size, pEntry->datagram.pBody);
+        pEntry = pEntry->pNextEntry;
+    }
+
+    printf ("Recv list head is at 0x%ld.\n", &gRecvDatagramListHead);
+    pEntry = &gRecvDatagramListHead;
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        printf (" %d: prev 0x%lx, next 0x%lx, inUse 0x%x, datagram.size %d, datagram \"%s\".\n",
+                x, pEntry->pPrevEntry, pEntry->pNextEntry, pEntry->inUse, pEntry->datagram.size, pEntry->datagram.pBody);
+        pEntry = pEntry->pNextEntry;
+    }
+}
+#endif
+
+// Set the phase of the module in a global variable
+static void getModulePhase (void)
+{
+    char * pVersion = NULL;
+
+    pVersion = pgNeul->getVersion();
+
+    if (pVersion != NULL)
+    {
+        printf ("Version: \"%s\", so ", pVersion);
+        if (strcmp(pVersion, "Neul CIoT Phase 2") == 0)
+        {
+            gModulePhase = MODULE_PHASE_2;
+            printf ("module is MODULE_PHASE_2.\n");
+        }
+        else if (strcmp(pVersion, "Neul CIoT") == 0)
+        {
+            gModulePhase = MODULE_PHASE_1;
+            printf ("module is MODULE_PHASE_1.\n");
+        }
+        else
+        {
+            printf ("module is MODULE_PHASE_UNKNOWN.\n");
+        }
+    }
+}
+
+#if 0
+// Convert to upper case
+// Not using this as found it didn't seem to work for the Chinese using their
+// terminal program.  Potential character set issues maybe?
+// Instead, please do a direct comparison against upper and lower case versions
+static char toUpper (char digit)
+{
+    if (digit >= 'a' && digit <= 'z')
+    {
+        digit &= ~0x20;
+    }
+
+    return digit;
+}
+#endif
+
+// Return true if digit is a valid hex
+// character, otherwise false
+static bool isValidHex (char digit)
+{
+    uint32_t x;
+    bool isValid = false;
+
+    for (x = 0; (x < sizeof (hexTable)) && !isValid; x++)
+    {
+        if (TO_UPPER(digit) == TO_UPPER(hexTable[x]))
+        {
+            isValid = true;
+        }
+    }
+
+    return isValid;
+}
+
+// Take a hex nibble and convert to a byte.
+static uint8_t hexToNibble (char digit)
+{
+    uint8_t nibbleValue = 0;
+
+    digit = TO_UPPER (digit);
+    if (isValidHex (digit))
+    {
+        if (digit >= '0' && digit <= '9')
+        {
+            nibbleValue = digit - '0';
+        }
+        else
+        {
+            if (digit >= 'A' && digit <= 'F')
+            {
+                nibbleValue = digit - 'A' + 10;
+            }
+        }
+    }
+
+    return nibbleValue;
+}
+
+// Take a hex value made up of digit1 and digit2
+// and return the corresponding byte value.
+// So if digit1 were 'a' and digit2 '3' the hex value
+// would be 0xA3.  Invalid hex digits are ignored.
+static uint8_t hexTobyte (char digit1, char digit2)
+{
+    return (hexToNibble (digit1) << 4) + hexToNibble (digit2);
+}
+
+// See if a character has been entered
+// at the PC serial port and return it,
+// or otherwise return 0.
+static char peekChar (void)
+{
+    char input = 0;
+    Serial pc (USBTX, USBRX);
+
+    pc.baud (PC_BAUD_RATE);
+
+    if (pc.readable())
+    {
+        input = pc.getc();
+    }
+
+    return input;
+}
+
+// Wait for a character to be entered
+// at the PC serial port and return it.
+static char getChar (void)
+{
+    Serial pc (USBTX, USBRX);
+
+    pc.baud (PC_BAUD_RATE);
+
+    return pc.getc();
+}
+
+// Get a string of numbers from the user as a hex
+// string and store it as a string of bytes in buf
+// String entry is terminated with <enter>, which is
+// NOT stored with the string and also no
+// terminator is stored.
+// If characters that aren't a valid part of a hex
+// string are entered they will be ignored.
+static uint32_t getUserHexString (uint32_t size, char * buf)
+{
+    char input;
+    char hexChar1 = 0;
+    bool done = false;
+    uint32_t charCount = 0;
+    uint32_t byteCount = 0;
+    Serial pc (USBTX, USBRX);
+
+    pc.baud (PC_BAUD_RATE);
+
+    while (!done && (byteCount < size))
+    {
+        input = pc.getc();
+        if (input == '\r')
+        {
+            done = true;
+        }
+        else
+        {
+            if (isValidHex(input))
+            {
+                pc.putc(input);
+                if (IS_EVEN (charCount))
+                {
+                    hexChar1 = input;
+                }
+                else
+                {
+                    buf[byteCount] = hexTobyte(hexChar1, input);
+                    byteCount++;
+                }
+                charCount++;
+            }
+        }
+    }
+
+    pc.putc('\n');
+
+    return byteCount;
+}
+
+/// Print a byte string as hex
+static void printByteString (uint32_t size, const char * buf)
+{
+    char hexBuf[MACTEST_STRING_MAX_SIZE * 2];
+    uint32_t x = 0;
+    uint32_t y = 0;
+
+    for (x = 0; (x < size) && (y < sizeof (hexBuf)); x++)
+    {
+        hexBuf[y] = hexTable[(buf[x] >> 4) & 0x0f]; // upper nibble
+        y++;
+        if (y < sizeof (hexBuf))
+        {
+            hexBuf[y] = hexTable[buf[x] & 0x0f]; // lower nibble
+            y++;
+        }
+    }
+
+    printf ("%.*s", (int) y, hexBuf);
+}
+
+// Print out the AT+MACTEST string
+static void printMactestString (uint32_t size, const char * string)
+{
+    if (size > 0)
+    {
+        printf ("The MACTEST string will be:\n");
+        printf ("AT+MACTEST=%d,", (int) size);
+        printByteString(size, string);
+        printf ("\n");
+    }
+    else
+    {
+        printf ("No MACTEST string has been set.\n");
+    }
+}
+
+// Enter transparent AT command mode until
+// CTRL-C is detected.
+static void transparentMode (void)
+{
+    char input;
+    bool done = false;
+    Serial pc (USBTX, USBRX);
+
+    pc.baud (PC_BAUD_RATE);
+
+    while (!done)
+    {
+        // transfer data from pc to modem
+        if (pc.readable() && pgNeul->writeable())
+        {
+            input = pc.getc();
+            if (input == '\x03') // CTRL-C
+            {
+                done = true;
+            }
+            else
+            {
+                pc.putc (input); // echo
+                pgNeul->putc (input);
+            }
+        }
+
+        // transfer data from modem to pc
+        if (pgNeul->readable() && pc.writeable())
+        {
+            pc.putc (pgNeul->getc());
+        }
+    }
+}
+
+// User configuration of the module
+// Should only be called after the module has been initialised
+static void configureModule (void)
+{
+    bool done = false;
+    uint32_t x;
+
+    printf ("%s\n", COLOUR_HIGHLIGHT);
+    /* get the phase of the module */
+    getModulePhase();
+
+    printf ("\n");
+    if (gModulePhase == MODULE_PHASE_UNKNOWN)
+    {
+        printf ("Phase of module SW unknown, skipping config...\n");
+    }
+    else
+    {
+        if (gModulePhase == MODULE_PHASE_1)
+        {
+            // Print out the AT+MACTEST command on the debug port and give the PC side
+            // some time to change it
+            printMactestString (readNvContext()->mactestStringSize, readNvContext()->mactestString);
+            printf ("Press 'y' within 5 seconds to change this, 'n' to continue. \n");
+        }
+        else
+        {
+            printf ("Press 'y' within 5 seconds to enter AT command mode. \n");
+        }
+
+        for (x = 0; (x < USER_WAIT_DECISECONDS) && !done; x++)
+        {
+            char input;
+            led = !led;
+            wait_ms (100);
+
+            input = peekChar();
+
+            if (input != 0)
+            {
+                printf ("You pressed '%c' (0x%x).\n", input, input);
+            }
+
+            if ((input == 'Y') || (input == 'y'))
+            {
+                uint32_t y;
+
+                led = 1;
+
+                if (gModulePhase == MODULE_PHASE_1)
+                {
+                    while (!done)
+                    {
+                        char string[MACTEST_STRING_MAX_SIZE];
+
+                        printf ("\n");
+                        printf ("Enter the new MACTEST string (just the part beyond the\n");
+                        printf ("comma) and press <enter>, or just press <enter> to clear\n");
+                        printf ("the current MACTEST string.  Backspace/delete will not work\n");
+                        printf ("but you can check your entry, and try again, before it is\n");
+                        printf ("committed: ");
+                        y = getUserHexString (sizeof (string), string);
+
+                        printf ("\n");
+                        printMactestString (y, string);
+
+                        printf ("\n");
+                        printf ("Is this correct? Press 'y' to save it, 'n' to try again,\n");
+                        printf ("any other key to continue without changes. ");
+                        input = getChar();
+                        printf ("\nYou pressed '%d'.\n", input);
+                        if ((input == 'Y') || (input == 'y'))
+                        {
+                            printf ("Saving...\n");
+                            nvram.nvContext.mactestStringSize = y;
+                            memcpy (nvram.nvContext.mactestString, string, y);
+                            writeNvContext (&nvram);
+                            done = true;
+                        }
+                        else
+                        {
+                            if (input != 'N')
+                            {
+                                printf ("OK, continuing...\n");
+                                done = true;
+                            }
+                        }
+                    }
+                }
+                else
+                {
+                    printf ("\n");
+                    printf ("You are now in transparent AT command mode with the modem.\n");
+                    printf ("Enter whatever commands are required to configure the modem\n");
+                    printf ("and press CTRL-C to continue.\n");
+                    transparentMode();
+                    done = true;
+                    printf ("\nContinuing...\n");
+                }
+            }
+            else
+            {
+                if ((input == 'N') || (input == 'n'))
+                {
+                    done = true;
+                    printf ("OK, continuing...\n");
+                }
+            }
+       }
+
+        if (x == USER_WAIT_DECISECONDS)
+        {
+            printf ("Timed out, no key-press detected...\n");
+        }
+
+        if ((gModulePhase == MODULE_PHASE_1) && (readNvContext()->mactestStringSize > 0))
+        {
+            // Send the mactest string to the module
+            // No need to do anything for a phase 2 module SW as those values are stored
+            // in NVRAM inside the module
+            printf ("Sending the MACTEST string to the module...\n");
+            if (pgNeul->sendMactest (readNvContext()->mactestStringSize, readNvContext()->mactestString))
+            {
+                printf ("Done.\n");
+            }
+            else
+            {
+                printf ("Module responded with ERROR.\n");
+            }
+        }
+    }
+
+    led = 0;
+
+    printf (COLOUR_DEFAULT);
+}
+
+// Asserts
+static void assert (bool condition, DebugSosType_t debugSosType, const char * pFormat, ...)
+{
+    if (!condition)
+    {
+        printf ("\n!!! ASSERT !!! ASSERT !!! ASSERT !!! ASSERT !!! ASSERT !!!\n");
+        va_list args;
+        va_start (args, pFormat);
+        printf (pFormat, args);
+        va_end (args);
+        printf ("\n!!! ASSERT !!! ASSERT !!! ASSERT !!! ASSERT !!! ASSERT !!!\n\n\n");
+        wait_ms (2000);
+        setWakeUpCode ((WakeUpCode_t) debugSosType);
+        debugSos (debugSosType);
+    }
+}
+
+static void assertAlways (DebugSosType_t debugSosType, const char * pFormat, ...)
+{
+    assert (false, debugSosType, pFormat);
+}
+
+/// Write to NVRAM, returning true if successful,
+// otherwise false.  The pointer pNvContext must be
+// on a 4 byte boundary and the structure size must
+// be a multiple of 4.
+static bool writeNvContext (Nvram_t * pNvram)
+{
+    bool success = false;
+    uint32_t iapResult;
+
+#ifdef DEBUG
+    printf ("Writing structure at 0x%08x to NVRAM.\n", pNvram);
+#endif
+    assert (((((uint32_t) pNvram) & 0x03) == 0), DEBUG_SOS_GENERIC_FAILURE, "pNvContext must be on a 4 byte boundary.");
+    assert (((sizeof (pNvram->rawBytes) & 0x03) == 0), DEBUG_SOS_GENERIC_FAILURE, "sizeof (pNvram->rawBytes) must be a multiple of 4.");
+
+    // Blank check: mbed erases all flash contents after downloading a new executable
+    iapResult = iap.blank_check (FLASH_SECTOR (USER_FLASH_AREA_START), FLASH_SECTOR (USER_FLASH_AREA_START));
+#ifdef DEBUG
+    printf ("NVRAM: blank check result = 0x%x\n", iapResult);
+#endif
+
+    // Erase sector, if required
+    if (iapResult == SECTOR_NOT_BLANK)
+    {
+        iap.prepare (FLASH_SECTOR (USER_FLASH_AREA_START), FLASH_SECTOR (USER_FLASH_AREA_START));
+        iapResult = iap.erase (FLASH_SECTOR (USER_FLASH_AREA_START), FLASH_SECTOR (USER_FLASH_AREA_START));
+#ifdef DEBUG
+        printf ("NVRAM: erase result = 0x%x\n", iapResult);
+#endif
+    }
+
+    // Copy RAM to Flash
+    iap.prepare (FLASH_SECTOR (USER_FLASH_AREA_START), FLASH_SECTOR (USER_FLASH_AREA_START));
+    iapResult = iap.write (&(pNvram->rawBytes[0]), sector_start_adress[FLASH_SECTOR (USER_FLASH_AREA_START)], sizeof (pNvram->rawBytes));
+#ifdef DEBUG
+    printf ("NVRAM: copied: SRAM (0x%08x) -> Flash (0x%08x), %d bytes, result = 0x%x\n", pNvram, sector_start_adress[FLASH_SECTOR (USER_FLASH_AREA_START)], sizeof (*pNvram), iapResult);
+#endif
+
+    // Compare
+    iapResult = iap.compare (&(pNvram->rawBytes[0]), sector_start_adress[FLASH_SECTOR (USER_FLASH_AREA_START)], sizeof (pNvram->rawBytes));
+    printf ("NVRAM: compare result = \"%s\"\n", iapResult ? "FAILED" : "OK" );
+    if (iapResult == CMD_SUCCESS)
+    {
+        success = true;
+    }
+
+    return success;
+}
+
+/// Write defaults to NVRAM and return
+// a pointer to the reset contents.
+static NvContext_t * resetNvContext (void)
+{
+    printf ("*** Resetting NVRAM to defaults.\n");
+
+    nvram.nvContext.id = NVRAM_ID;
+    nvram.nvContext.devModeOnNotOff = false;
+    nvram.nvContext.wakeUpCode = WAKE_UP_CODE_OK;
+    nvram.nvContext.readingIntervalSeconds = DEFAULT_READING_INTERVAL_SECONDS;
+    nvram.nvContext.flashOnNotOff = true;
+    nvram.nvContext.ledOnNotOff = false;
+    memcpy (nvram.nvContext.mactestString, defaultMactestString, sizeof (defaultMactestString));
+    nvram.nvContext.mactestStringSize = sizeof (defaultMactestString);
+
+    // Ignore the return value - must always return an answer
+    writeNvContext (&nvram);
+
+    return &(nvram.nvContext);
+}
+
+/// Read from NVRAM, always guaranteed to produce
+// a result (may be default values).
+static NvContext_t * readNvContext (void)
+{
+    NvContext_t * pNvContext = NULL;
+    uint32_t iapResult;
+
+    // Blank check
+    iapResult = iap.blank_check (FLASH_SECTOR (USER_FLASH_AREA_START), FLASH_SECTOR (USER_FLASH_AREA_START));
+
+    if (iapResult == SECTOR_NOT_BLANK)
+    {
+        if (nvram.nvContext.id != NVRAM_ID)
+        {
+#ifdef DEBUG
+            printf ("Loading NVRAM...\n");
+#endif
+            memcpy (&(nvram.rawBytes[0]), (const char *) USER_FLASH_AREA_START, sizeof (nvram.rawBytes));
+        }
+
+        if (nvram.nvContext.id == NVRAM_ID)
+        {
+            // Contents are valid
+            pNvContext = &(nvram.nvContext);
+        }
+        else
+        {
+#ifdef DEBUG
+            printf ("NVRAM contents invalid.\n");
+            // Contents are not valid so set them up
+#endif
+            pNvContext = resetNvContext ();
+        }
+    }
+    else
+    {
+#ifdef DEBUG
+        printf ("NVRAM blank.\n");
+#endif
+        // Contents are not there so set them up
+        pNvContext = resetNvContext ();
+    }
+
+    return pNvContext;
+}
+
+/// Do the flash thing, should be called on a Send
+static void doSendFlash (void)
+{
+    if (readNvContext()->flashOnNotOff)
+    {
+        led = !led;
+        wait_ms (FLASH_DURATION_MS);
+        led = !led;
+    }
+}
+
+/// Do the other flash thing, should be called on a Receive
+static void doRecvFlash (void)
+{
+    if (readNvContext()->flashOnNotOff)
+    {
+        led = !led;
+        wait_ms (FLASH_DURATION_MS /4);
+        led = !led;
+        wait_ms (FLASH_DURATION_MS /4);
+        led = !led;
+        wait_ms (FLASH_DURATION_MS /4);
+        led = !led;
+    }
+}
+
+/// Set the state of a GPIO
+static bool setGpio (GpioState_t * pGpioState)
+{
+    bool success = false;
+
+    if (pGpioState->gpio < (sizeof (gpioTable) / sizeof (gpioTable[0])))
+    {
+        if (pGpioState->inputNotOutput)
+        {
+            DigitalIn((PinName) gpioTable[pGpioState->gpio]);
+        }
+        else
+        {
+            DigitalOut * pOutput = new DigitalOut((PinName) gpioTable[pGpioState->gpio]);
+            *pOutput = pGpioState->onNotOff;
+        }
+        success = true;
+    }
+
+    return success;
+}
+
+/// Get the state of a GPIO
+static bool getGpio (GpioState_t * pGpioState)
+{
+    bool success = false;
+
+    if (pGpioState->gpio < (sizeof (gpioTable) / sizeof (gpioTable[0])))
+    {
+        if (pGpioState->inputNotOutput)
+        {
+            DigitalIn *pInput = new DigitalIn((PinName) gpioTable[pGpioState->gpio]);
+            pGpioState->onNotOff = *pInput;
+        }
+        else
+        {
+            DigitalOut *pOutput = new DigitalOut((PinName) gpioTable[pGpioState->gpio]);
+            pGpioState->onNotOff = *pOutput;
+        }
+        success = true;
+    }
+
+    return success;
+}
+
+/// Set the wake-up code
+static void setWakeUpCode (WakeUpCode_t wakeUpCode)
+{
+    if (nvram.nvContext.wakeUpCode != wakeUpCode)
+    {
+        nvram.nvContext.id = NVRAM_ID;
+        nvram.nvContext.wakeUpCode = wakeUpCode;
+        writeNvContext (&nvram);
+    }
+}
+
+/// Set development mode
+static void setDevMode (bool onNotOff)
+{
+    if (nvram.nvContext.devModeOnNotOff != onNotOff)
+    {
+        nvram.nvContext.id = NVRAM_ID;
+        nvram.nvContext.devModeOnNotOff = onNotOff;
+        writeNvContext (&nvram);
+    }
+}
+
+/// Set the reading interval in seconds
+static void setReadingIntervalSeconds (uint32_t readingIntervalSeconds)
+{
+    if (nvram.nvContext.readingIntervalSeconds != readingIntervalSeconds)
+    {
+        nvram.nvContext.id = NVRAM_ID;
+        nvram.nvContext.readingIntervalSeconds = readingIntervalSeconds;
+        writeNvContext (&nvram);
+    }
+}
+
+/// Set the LED state
+static void setLed (bool onNotOff)
+{
+    if (nvram.nvContext.ledOnNotOff != onNotOff)
+    {
+        nvram.nvContext.id = NVRAM_ID;
+        nvram.nvContext.ledOnNotOff = onNotOff;
+        writeNvContext (&nvram);
+    }
+    led = nvram.nvContext.ledOnNotOff;
+}
+
+/// Set the Flash state
+static void setFlash (bool onNotOff)
+{
+    if (nvram.nvContext.flashOnNotOff != onNotOff)
+    {
+        nvram.nvContext.id = NVRAM_ID;
+        nvram.nvContext.flashOnNotOff = onNotOff;
+        writeNvContext (&nvram);
+    }
+}
+
+/// Initialise ourselves
+static bool init (void)
+{
+    bool success = true;
+    uint32_t x;
+    GpioState_t waterPumpGpio = {GPIO_WATER_PUMP, false, false};
+    DatagramEntry_t * pPrevEntry = &gFreeDatagramListHeadUnused;
+    DatagramEntry_t ** ppEntry = &(gFreeDatagramListHeadUnused.pNextEntry);
+
+    memset (&gFreeDatagramListHeadUnused, 0, sizeof (gFreeDatagramListHeadUnused));
+    memset (&gSendDatagramListHead, 0, sizeof (gSendDatagramListHead));
+    memset (&gRecvDatagramListHead, 0, sizeof (gRecvDatagramListHead));
+
+    // Create a malloc()ed free list attached to the (unused) static
+    // head of the free list
+    for (x = 1; (x < MAX_NUM_DATAGRAMS) && success; x++)  // from 1 as it's from head.pNextEntry onwards
+    {
+        *ppEntry = (DatagramEntry_t *) malloc (sizeof (DatagramEntry_t));
+        if (*ppEntry != NULL)
+        {
+            memset (*ppEntry, 0, sizeof (**ppEntry));
+            // Link it in
+            (*ppEntry)->pPrevEntry = pPrevEntry;
+            (*ppEntry)->pNextEntry = NULL;
+            (*ppEntry)->inUse = false;
+            if (pPrevEntry != NULL)
+            {
+                pPrevEntry->pNextEntry = *ppEntry;
+            }
+            pPrevEntry = *ppEntry;
+
+            // Next
+            ppEntry = &((*ppEntry)->pNextEntry);
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "failed malloc().");
+            success = false;
+        }
+    }
+
+#ifdef DEBUG
+    debugPrintLists ();
+#endif
+
+    if (success)
+    {
+        /* set the water pump control pin to an output and to off */
+        success = setGpio (&waterPumpGpio);
+        assert (success, DEBUG_SOS_GENERIC_FAILURE, "failed to set water pump pin.");
+
+        if (success)
+        {
+            // Check NVRAM
+            printf ("\n=== IAP: NVRAM check ===\n");
+            printf ("  device-ID = 0x%08x\n", iap.read_ID());
+            printf ("  serial# = 0x%08x\n", iap.read_serial());
+            printf ("  CPU running at %ld MHz\n", SystemCoreClock / 1000000);
+            printf ("  user reserved flash area: start_address = 0x%08lx\n", (long unsigned int) iap.reserved_flash_area_start());
+            printf ("                            size = %d bytes\n", iap.reserved_flash_area_size());
+            printf ("  read_BootVer = 0x%08x\n", iap.read_BootVer());
+            printf ("  local ID value = 0x%08lx\n", readNvContext()->id);
+
+            // And finally, setup the LED.
+            led = readNvContext()->ledOnNotOff;
+        }
+    }
+
+    return success;
+}
+
+/// Tidy up
+static void deInit (void)
+{
+    uint32_t x = 0;
+    DatagramEntry_t * pEntry = NULL;
+
+    // Return send datagram memory to the free list
+    freeAllDatagrams (&gSendDatagramListHead);
+    // Return receive datagram memory to the free list
+    freeAllDatagrams (&gRecvDatagramListHead);
+
+    // Free the free list from the end
+    pEntry = &gFreeDatagramListHeadUnused;
+    for (x = 0; (pEntry->pNextEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        pEntry = pEntry->pNextEntry;
+    }
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        DatagramEntry_t * pNextOne = pEntry->pPrevEntry;
+        free (pEntry);
+        pEntry = pNextOne;
+    }
+}
+
+/// Allocate room for a datagram from the given list, returning a pointer
+// to it or NULL if unsuccessful
+static Datagram_t * allocDatagram (DatagramEntry_t * pDatagramListHead)
+{
+    Datagram_t * pAlloc = NULL;
+    uint32_t x = 0;
+    DatagramEntry_t * pEntry;
+
+    // If there is already an unused entry in the list, just return it
+    pEntry = pDatagramListHead;
+    for (x = 0; (pEntry != NULL) && (pEntry->inUse) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        pEntry = pEntry->pNextEntry;
+    }
+
+    if ((pEntry != NULL) && (!pEntry->inUse))
+    {
+#ifdef DEBUG
+        printf ("allocDatagram: found existing unused entry in list.\n");
+#endif
+        // Good, use this one
+        memset (&(pEntry->datagram), 0, sizeof (pEntry->datagram));
+        pEntry->inUse = true;
+        pAlloc = &(pEntry->datagram);
+    }
+    else
+    {
+#ifdef DEBUG
+        printf ("allocDatagram: finding malloc()ed entry in the free list...\n");
+#endif
+        // Find the malloc()ed entry at the end of the free list
+        pEntry = &gFreeDatagramListHeadUnused;
+        for (x = 0; (pEntry->pNextEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+        {
+            pEntry = pEntry->pNextEntry;
+        }
+
+        // If there is one, move it to the given list
+        if ((pEntry != NULL) && (pEntry->pNextEntry == NULL) && pEntry != &gFreeDatagramListHeadUnused)
+        {
+            DatagramEntry_t * pWantedEntry = pEntry;
+
+            // Unlink it from the end of the free list
+            if (pWantedEntry->pPrevEntry != NULL)
+            {
+                pWantedEntry->pPrevEntry->pNextEntry = pWantedEntry->pNextEntry;
+                pWantedEntry->pPrevEntry = NULL;
+            }
+
+            // Attach it to the end of the given list
+            pEntry = pDatagramListHead;
+            for (x = 0; (pEntry->pNextEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+            {
+                pEntry = pEntry->pNextEntry;
+            }
+
+            if (pEntry->pNextEntry == NULL)
+            {
+                pEntry->pNextEntry = pWantedEntry;
+                pWantedEntry->pPrevEntry = pEntry;
+                pWantedEntry->inUse = true;
+                pAlloc = &(pWantedEntry->datagram);
+            }
+            else
+            {
+                assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "allocDatagram: failed to find end of list (x = %d).", x);
+            }
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "allocDatagram: failed to find malloc()ed entry in free list (x = %d).", x);
+        }
+
+    }
+
+    return pAlloc;
+}
+
+/// Allocate room for a send datagram, returning a pointer
+// to it or to NULL if unsuccessful
+static Datagram_t * allocSendDatagram (void)
+{
+    return allocDatagram (&gSendDatagramListHead);
+}
+
+/// Allocate room for a receive datagram, returning a pointer
+// to it or to NULL if unsuccessful
+static Datagram_t * allocRecvDatagram (void)
+{
+    return allocDatagram (&gRecvDatagramListHead);
+}
+
+/// Free a datagram from the given list
+static void freeDatagram (Datagram_t *pDatagram, DatagramEntry_t * pDatagramListHead)
+{
+    uint32_t x = 0;
+    DatagramEntry_t * pEntry;
+
+    if (pDatagram != NULL)
+    {
+#ifdef DEBUG
+        printf ("Freeing a datagram (at 0x%lx)...\n", pDatagram);
+#endif
+        // Find the entry in the list
+        pEntry = pDatagramListHead;
+        for (x = 0; (pEntry != NULL) && (&(pEntry->datagram) != pDatagram) && (x < MAX_NUM_DATAGRAMS); x++)
+        {
+            pEntry = pEntry->pNextEntry;
+        }
+
+        if ((pEntry != NULL) && (&(pEntry->datagram) == pDatagram))
+        {
+            DatagramEntry_t * pWantedEntry = pEntry;
+
+#ifdef DEBUG
+            printf ("Found the datagram.\n");
+#endif
+            // Found it, mark it as not in use and, if it is a malloc()ed
+            // entry, unlink it from the current list and move it to the
+            // free list
+            pWantedEntry->inUse = false;
+            memset (&(pWantedEntry->datagram), 0, sizeof (pWantedEntry->datagram));
+            if (pWantedEntry != pDatagramListHead)
+            {
+#ifdef DEBUG
+                printf ("freeDatagram: moving malloc()ed entry to free list.\n");
+#endif
+                if (pWantedEntry->pPrevEntry != NULL)
+                {
+                    pWantedEntry->pPrevEntry->pNextEntry = pWantedEntry->pNextEntry;
+                    pWantedEntry->pPrevEntry = NULL;
+                }
+                if (pWantedEntry->pNextEntry != NULL)
+                {
+                    pWantedEntry->pNextEntry->pPrevEntry = pWantedEntry->pPrevEntry;
+                    pWantedEntry->pNextEntry = NULL;
+                }
+
+                // Find the end of the free list
+                pEntry = &gFreeDatagramListHeadUnused;
+                for (x = 0; (pEntry->pNextEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+                {
+                    pEntry = pEntry->pNextEntry;
+                }
+
+                // Link it there
+                if (pEntry->pNextEntry == NULL)
+                {
+                    pEntry->pNextEntry = pWantedEntry;
+                    pWantedEntry->pPrevEntry = pEntry;
+                }
+                else
+                {
+                    assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "freeDatagram: failed to find end of free list (x = %d).", x);
+                }
+            }
+#ifdef DEBUG
+            else
+            {
+                printf ("freeDatagram: just marking head entry as unused.\n");
+            }
+#endif
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM,
+                          "freeDatagram: couldn't find entry in list (pDatagram = 0x%lx, gDatagramListHead = 0x%lx, x = %d).",
+                          pDatagram, pDatagramListHead, x);
+        }
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "freeDatagram: NULL pointer passed in.");
+    }
+}
+
+/// Free a specific datagram from the receive list
+static void freeRecvDatagram (Datagram_t *pDatagram)
+{
+    freeDatagram (pDatagram, &gRecvDatagramListHead);
+}
+
+// Empty a datagram list (either send or receive)
+static void freeAllDatagrams (DatagramEntry_t *pDatagramListHead)
+{
+    uint32_t x;
+    DatagramEntry_t * pEntry = NULL;
+
+    pEntry = pDatagramListHead;
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        pEntry->inUse = false;
+        pEntry = pEntry->pNextEntry;
+    }
+
+    freeUnusedDatagrams(pDatagramListHead);
+}
+
+/// Free unused datagrams from the send or receive lists
+static void freeUnusedDatagrams (DatagramEntry_t *pDatagramListHead)
+{
+    uint32_t x = 0;
+    DatagramEntry_t * pEntry = NULL;
+
+    if ((pDatagramListHead != NULL) && (pDatagramListHead != &gFreeDatagramListHeadUnused))
+    {
+        // Go to the end of the list
+        pEntry = pDatagramListHead;
+        for (x = 0; (pEntry->pNextEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+        {
+            pEntry = pEntry->pNextEntry;
+        }
+
+        if ((pEntry != NULL) && (pEntry->pNextEntry == NULL))
+        {
+            // Now work backwards up the list freeing unused things until we get
+            // to the head
+            for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+            {
+                DatagramEntry_t * pNextOne = pEntry->pPrevEntry;
+                // Check that this entry is unused and not the first static entry then,
+                // if it is, free it
+                if ((!(pEntry->inUse)) && (pEntry != pDatagramListHead))
+                {
+                    freeDatagram (&(pEntry->datagram), pDatagramListHead);
+#ifdef DEBUG
+                    printf ("freeUnusedDatagrams: freeing an entry.\n");
+#endif
+                }
+                pEntry = pNextOne;
+            }
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "freeUnusedDatagrams : failed to find end of list (x = %d).", x);
+        }
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "freeUnusedDatagrams: NULL or free list head pointer passed in (== 0x%lx).", pDatagramListHead);
+    }
+}
+
+/// Free unused datagrams from the send list
+static void freeUnusedSendDatagrams (void)
+{
+    freeUnusedDatagrams (&gSendDatagramListHead);
+}
+
+/// Free unused datagrams from the receive list
+static void freeUnusedRecvDatagrams (void)
+{
+    freeUnusedDatagrams (&gRecvDatagramListHead);
+}
+
+/// Wait for the device to register on the network
+static bool waitReg (uint32_t durationSeconds)
+{
+    uint32_t count = 0;
+    bool success = false;
+
+    while (!success && (count < durationSeconds))
+    {
+        success = pgNeul->checkNetStatus (NULL);
+        wait_ms (1000);
+        count++;
+    }
+
+    return success;
+}
+
+/// Do Sending (working through the inUse datagrams in the Send queue) and
+// then a Receive of a single datagram (putting it in the Receive queue).
+// \return true if the send was successful, otherwise false.
+static bool sendAndReceive (void)
+{
+    bool success = true; // Set to true as otherwise will fail if there's nothing to send
+    uint32_t x;
+    DatagramEntry_t * pEntry;
+    Datagram_t *pRecvDatagram;
+    bool somethingInRxQueue = false;
+
+#ifdef DEBUG
+    printf ("\nSending datagram(s)...\n");
+#endif
+    // Do the sending first
+    pEntry = &gSendDatagramListHead;
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS) && success; x++)
+    {
+        if (pEntry->inUse)
+        {
+            success = false;
+            printf ("\nSending datagram %ld...\n", x);
+            // Send the datagram.
+            if (pgNeul != NULL)
+            {
+                success = pgNeul->datagramSend (pEntry->datagram.size, pEntry->datagram.pBody);
+            }
+
+            if (success)
+            {
+                doSendFlash();
+                printf ("Sent.\n");
+            }
+            else
+            {
+                assertAlways (DEBUG_SOS_NETWORK_SEND_PROBLEM, "Couldn't send datagram.");
+            }
+
+            // Lose it always, don't want to clog up
+            pEntry->inUse = false;
+        }
+        pEntry = pEntry->pNextEntry; // Move to the next entry
+    }
+
+    freeUnusedSendDatagrams();
+
+    // Now the receiving
+    do
+    {
+        somethingInRxQueue = false;
+        pRecvDatagram = allocRecvDatagram ();
+        if (pRecvDatagram != NULL)
+        {
+#ifdef DEBUG
+            printf ("Checking for downlink...\n");
+#endif
+            pRecvDatagram->size = sizeof (pRecvDatagram->pBody);
+            // Don't check the return value here (as we don't want to fail
+            // if nothing has been received) check the size returned instead
+            if (pgNeul != NULL)
+            {
+                somethingInRxQueue  = pgNeul->datagramRecv ((int *) &(pRecvDatagram->size), pRecvDatagram->pBody, RECEIVE_DURATION_MS);
+            }
+            // If something was received say so, otherwise free the buffer
+            if (somethingInRxQueue && (pRecvDatagram->size > 0))
+            {
+                doRecvFlash ();
+                printf ("A datagram was received.\n");
+            }
+            else
+            {
+                freeRecvDatagram (pRecvDatagram);
+            }
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate a datagram for receive.");
+        }
+    }
+    while (somethingInRxQueue);
+
+    return success;
+}
+
+/// Prepare an InitInd, plus a SerialNumberInd.
+// \param indNotCnf  if true encode an initInt, else encode an initCnf
+// \return true if the preparation was successful, otherwise false.
+static bool queueInitialDatagram (void)
+{
+    bool success = false;
+    InitIndUlMsg_t initIndUlMsg;
+    SerialNumberIndUlMsg_t serialNumberIndUlMsg;
+    Datagram_t * pDatagram;
+    uint32_t bytesEncoded = 0;
+
+    printf ("\nPreparing initial datagram...\n");
+
+    pDatagram = allocSendDatagram();
+    if (pDatagram != NULL)
+    {
+        printf ("Reading serial number from water meter...\n");
+        // Read the serial number from the water meter
+        gWaterMeter.readSerialNumber (&(serialNumberIndUlMsg.serialNumber));
+        // Ignore the return value and just set success == true so that the code
+        // can run without a water meter attached.
+        success = true;
+        if (success)
+        {
+            printf ("Serial number is %ld.\n", serialNumberIndUlMsg.serialNumber);
+
+            // Encode the InitInd and SerialNumberInd messages into a datagram
+            printf ("Encoding datagram...\n");
+
+            // Set up the InitInd contents
+            initIndUlMsg.wakeUpCode = readNvContext()->wakeUpCode;
+            printf ("Wake-up code is 0x%x.\n", initIndUlMsg.wakeUpCode);
+
+            setWakeUpCode (WAKE_UP_CODE_OK);
+            bytesEncoded += gMessageCodec.encodeInitIndUlMsg (&(pDatagram->pBody[bytesEncoded]), &initIndUlMsg);
+            bytesEncoded += gMessageCodec.encodeSerialNumberIndUlMsg (&(pDatagram->pBody[bytesEncoded]), &serialNumberIndUlMsg);
+            pDatagram->size = bytesEncoded;
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_WATER_METER_PROBLEM, "Failed to read serial number from water meter.");
+        }
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+    }
+
+    return success;
+}
+
+/// Prepare the periodic datagram.
+// \return true if the preparation was successful, otherwise false.
+static bool queuePeriodicDatagram (void)
+{
+    bool success = false;
+    VolumeIndUlMsg_t volumeIndMsg;
+    RssiIndUlMsg_t rssiIndMsg;
+    uint32_t bytesEncoded =  0;
+    Datagram_t * pDatagram;
+
+    printf ("\nPreparing periodic datagram...\n");
+
+    pDatagram = allocSendDatagram();
+    if (pDatagram != NULL)
+    {
+        // Read the volume in litres
+        printf ("Reading volume from water meter...\n");
+        gWaterMeter.readLitres (&(volumeIndMsg.volumeLitres));
+        printf ("Volume is %ld litres.\n", volumeIndMsg.volumeLitres);
+
+        // Ignore the return value and just set success == true so that the code
+        // can run without a water meter attached.
+        success = true;
+
+        if (success)
+        {
+            // Read the RSSI
+            printf ("Reading RSSI from module...\n");
+            if (pgNeul != NULL)
+            {
+                success = pgNeul->getRssi ((int *) &(rssiIndMsg.rssi));
+                printf ("RSSI is %ld.\n", rssiIndMsg.rssi);
+            }
+            if (success)
+            {
+                printf ("Encoding datagram...\n");
+                // Encode the VolumeInd and RssiInd messages into a datagram
+                bytesEncoded += gMessageCodec.encodeVolumeIndUlMsg (&(pDatagram->pBody[bytesEncoded]), &volumeIndMsg);
+                bytesEncoded += gMessageCodec.encodeRssiIndUlMsg (&(pDatagram->pBody[bytesEncoded]), &rssiIndMsg);
+                pDatagram->size = bytesEncoded;
+            }
+            else
+            {
+                assertAlways (DEBUG_SOS_AT_COMMAND_PROBLEM, "Failed to read RSSI from module.");
+            }
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_WATER_METER_PROBLEM, "Failed to read volume from water meter.");
+        }
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+    }
+
+    return success;
+}
+
+/// Handle a SerialNumberGetReq message
+static bool handleSerialNumberGetReqDlMsg (void)
+{
+    bool success = false;
+    SerialNumberGetCnfUlMsg_t serialNumberGetCnfUlMsg;
+    uint32_t bytesEncoded =  0;
+    Datagram_t * pDatagram;
+
+    printf ("\nHandling SerialNumberGetReqDlMsg.\n");
+    printf ("Reading serial number from water meter...\n");
+    // Read the serial number from the water meter
+    gWaterMeter.readSerialNumber (&(serialNumberGetCnfUlMsg.serialNumber));
+
+    // Ignore the return value and just set success == true so that the code
+    // can run without a water meter attached.
+    success = true;
+
+    if (success)
+    {
+        printf ("Serial number is %ld.\n", serialNumberGetCnfUlMsg.serialNumber);
+        printf ("Preparing SerialNumberGetCnfUlMsg response in a datagram...\n");
+        pDatagram = allocSendDatagram();
+        if (pDatagram != NULL)
+        {
+            // Encode the serialNumberGetCnfUlMsg into a datagram
+            printf ("Encoding datagram...\n");
+
+            bytesEncoded += gMessageCodec.encodeSerialNumberGetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &serialNumberGetCnfUlMsg);
+
+            pDatagram->size = bytesEncoded;
+            success = true;
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+        }
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_WATER_METER_PROBLEM, "Failed to read volume from water meter.");
+    }
+
+    return success;
+}
+
+/// Handle a RebootReq message
+static bool handleRebootReqDlMsg (bool devModeOnNotOff)
+{
+    bool success = true;
+    printf ("\nHandling RebootReqDlMsg, devMode is 0x%d.\n", devModeOnNotOff);
+
+    setDevMode (devModeOnNotOff);
+
+    wait_ms (1000);
+
+    printf ("Resetting system...\n");
+    wait_ms (2000);
+    NVIC_SystemReset();
+
+    return success;
+}
+
+/// Enqueue a ReadingIntervalSetCnf or a ReadingIntervalGetCnf message
+static bool enqueueReadingIntervalSetGetCnfUlMsg (bool setNotGet)
+{
+    bool success = false;
+    uint32_t bytesEncoded =  0;
+    Datagram_t * pDatagram;
+
+     printf ("Preparing ReadingIntervalxxxCnfUlMsg response...\n");
+     pDatagram = allocSendDatagram();
+     if (pDatagram != NULL)
+     {
+         // Encode the ledxxxCnfUlMsg into a datagram
+         printf ("Encoding datagram...\n");
+         if (setNotGet)
+         {
+             ReadingIntervalSetCnfUlMsg_t readingIntervalSetCnfUlMsg;
+
+             readingIntervalSetCnfUlMsg.readingIntervalSeconds = readNvContext()->readingIntervalSeconds;
+             bytesEncoded += gMessageCodec.encodeReadingIntervalSetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &readingIntervalSetCnfUlMsg);
+         }
+         else
+         {
+             ReadingIntervalGetCnfUlMsg_t readingIntervalGetCnfUlMsg;
+
+             readingIntervalGetCnfUlMsg.readingIntervalSeconds = readNvContext()->readingIntervalSeconds;
+             bytesEncoded += gMessageCodec.encodeReadingIntervalGetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &readingIntervalGetCnfUlMsg);
+         }
+
+         pDatagram->size = bytesEncoded;
+         success = true;
+     }
+     else
+     {
+         assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+     }
+
+     return success;
+}
+
+/// Handle a ReadingIntervalSetReq message
+static bool handleReadingIntervalSetReqDlMsg (uint32_t readingIntervalSeconds)
+{
+    printf ("\nHandling ReadingIntervalSetReqDlMsg, set to %ld.\n", readingIntervalSeconds);
+    setReadingIntervalSeconds (readingIntervalSeconds);
+
+    return enqueueReadingIntervalSetGetCnfUlMsg (true);
+}
+
+/// Handle a ReadingIntervalGetReq message
+static bool handleReadingIntervalGetReqDlMsg (void)
+{
+     printf ("\nHandling ReadingIntervalGetReqDlMsg.\n");
+
+     return enqueueReadingIntervalSetGetCnfUlMsg (false);
+}
+
+/// Enqueue a GpioSetCnf or a GpioGetCnf message
+static bool enqueueGpioSetGetCnfUlMsg (bool setNotGet, GpioState_t * gpioState)
+{
+    bool success = false;
+    uint32_t bytesEncoded =  0;
+    Datagram_t * pDatagram;
+
+     printf ("Preparing GpioxxxCnfUlMsg response in a datagram...\n");
+     pDatagram = allocSendDatagram();
+     if (pDatagram != NULL)
+     {
+         // Encode the gpioxxxCnfUlMsg into a datagram
+         printf ("Encoding datagram...\n");
+         if (setNotGet)
+         {
+             GpioSetCnfUlMsg_t gpioSetCnfUlMsg;
+
+             gpioSetCnfUlMsg.gpioState = *gpioState;
+             bytesEncoded += gMessageCodec.encodeGpioSetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &gpioSetCnfUlMsg);
+         }
+         else
+         {
+             GpioGetCnfUlMsg_t gpioGetCnfUlMsg;
+
+             gpioGetCnfUlMsg.gpioState = *gpioState;
+             bytesEncoded += gMessageCodec.encodeGpioGetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &gpioGetCnfUlMsg);
+         }
+
+         pDatagram->size = bytesEncoded;
+         success = true;
+     }
+     else
+     {
+         assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+     }
+
+     return success;
+}
+
+/// Handle a GpioSetReq message
+static bool handleGpioSetReqDlMsg (GpioState_t * pGpioState)
+{
+    bool success = false;
+
+    printf ("\nHandling GpioSetReqDlMsg, gpio %d, inputNotOutput 0x%x, onNotOff 0x%x.\n",
+            pGpioState->gpio,
+            pGpioState->inputNotOutput,
+            pGpioState->onNotOff);
+
+    success = setGpio (pGpioState);
+
+    if (success)
+    {
+        success = enqueueGpioSetGetCnfUlMsg (true, pGpioState);
+    }
+
+    return success;
+}
+
+/// Handle a GpioGetReq message
+static bool handleGpioGetReqDlMsg (uint8_t gpio)
+{
+    bool success = false;
+    GpioState_t gpioState;
+
+    printf ("\nHandling GpioGetReqDlMsg, gpio %d.\n", gpio);
+
+    gpioState.gpio = gpio;
+    success = getGpio (&gpioState);
+
+    if (success)
+    {
+        success = enqueueGpioSetGetCnfUlMsg (false, &gpioState);
+    }
+
+    return success;
+}
+
+/// Enqueue an LedSetCnf or an LedGetCnf message
+static bool enqueueLedSetGetCnfUlMsg (bool setNotGet)
+{
+    bool success = false;
+    uint32_t bytesEncoded =  0;
+    Datagram_t * pDatagram;
+
+     printf ("Preparing LedxxxCnfUlMsg response in a datagram...\n");
+     pDatagram = allocSendDatagram();
+     if (pDatagram != NULL)
+     {
+         // Encode the ledxxxCnfUlMsg into a datagram
+         printf ("Encoding datagram...\n");
+         if (setNotGet)
+         {
+             LedSetCnfUlMsg_t ledSetCnfUlMsg;
+
+             ledSetCnfUlMsg.onNotOff = readNvContext()->ledOnNotOff;
+             bytesEncoded += gMessageCodec.encodeLedSetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &ledSetCnfUlMsg);
+         }
+         else
+         {
+             LedGetCnfUlMsg_t ledGetCnfUlMsg;
+
+             ledGetCnfUlMsg.onNotOff = readNvContext()->ledOnNotOff;
+             bytesEncoded += gMessageCodec.encodeLedGetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &ledGetCnfUlMsg);
+         }
+
+         pDatagram->size = bytesEncoded;
+         success = true;
+     }
+     else
+     {
+         assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+     }
+
+     return success;
+}
+
+/// Handle an LedSetReq message
+static bool handleLedSetReqDlMsg (bool onNotOff)
+{
+    printf ("\nHandling LedSetReqDlMsg, set gLedOnNotOff to 0x%x.\n", onNotOff);
+    setLed (onNotOff);
+
+    return enqueueLedSetGetCnfUlMsg (true);
+}
+
+/// Handle an LedGetReq message
+static bool handleLedGetReqDlMsg (void)
+{
+     printf ("\nHandling LedGetReqDlMsg.\n");
+
+     return enqueueLedSetGetCnfUlMsg (false);
+}
+
+/// Enqueue a FlashSetCnf or a FlashGetCnf message
+static bool enqueueFlashSetGetCnfUlMsg (bool setNotGet)
+{
+    bool success = false;
+    uint32_t bytesEncoded =  0;
+    Datagram_t * pDatagram;
+
+     printf ("Preparing FlashxxxCnfUlMsg response in a datagram...\n");
+     pDatagram = allocSendDatagram();
+     if (pDatagram != NULL)
+     {
+         // Encode the flashSetCnfUlMsg or flashGetCnfUlMsg into a datagram
+         printf ("Encoding datagram...\n");
+         if (setNotGet)
+         {
+             FlashSetCnfUlMsg_t flashSetCnfUlMsg;
+
+             flashSetCnfUlMsg.onNotOff = readNvContext()->flashOnNotOff;
+             bytesEncoded += gMessageCodec.encodeFlashSetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &flashSetCnfUlMsg);
+         }
+         else
+         {
+             FlashGetCnfUlMsg_t flashGetCnfUlMsg;
+
+             flashGetCnfUlMsg.onNotOff = readNvContext()->flashOnNotOff;
+             bytesEncoded += gMessageCodec.encodeFlashGetCnfUlMsg (&(pDatagram->pBody[bytesEncoded]), &flashGetCnfUlMsg);
+         }
+
+         pDatagram->size = bytesEncoded;
+         success = true;
+     }
+     else
+     {
+         assertAlways (DEBUG_SOS_MEMORY_ALLOC_PROBLEM, "Couldn't allocate send datagram.");
+     }
+
+     return success;
+}
+
+/// Handle a FlashSetReq message
+static bool handleFlashSetReqDlMsg (bool onNotOff)
+{
+    printf ("\nHandling FlashSetReqDlMsg, set gFlashOnNotOff to 0x%x.\n", onNotOff);
+    setFlash (onNotOff);
+
+    return enqueueFlashSetGetCnfUlMsg (true);
+}
+
+/// Handle a FlashGetReq message
+static bool handleFlashGetReqDlMsg (void)
+{
+    printf ("\nHandling FlashGetReqDlMsg.\n");
+
+    return enqueueFlashSetGetCnfUlMsg (false);
+}
+
+/// Process any received datagrams, queueing any response datagrams
+// as appropriate.
+static bool processReceivedDatagrams (void)
+{
+    bool success = true;
+    uint32_t x;
+    DlMsgUnion_t dlMsg;
+    MessageCodec::DecodeResult_t decodeResult;
+    DatagramEntry_t * pEntry;
+    const char * pBuffer;
+
+#ifdef DEBUG
+    printf ("\nProcessing received datagrams...\n");
+#endif
+
+    pEntry = &gRecvDatagramListHead;
+    for (x = 0; (pEntry != NULL) && (x < MAX_NUM_DATAGRAMS); x++)
+    {
+        if (pEntry->inUse)
+        {
+            printf ("\nProcessing %ld (%ld bytes).\n", x, pEntry->datagram.size);
+            pBuffer = pEntry->datagram.pBody;
+
+            // Go through the entire datagram buffer looking for messages
+            while (pBuffer < (pEntry->datagram.pBody + pEntry->datagram.size))
+            {
+                decodeResult = gMessageCodec.decodeDlMsg (&pBuffer, pEntry->datagram.size, &dlMsg);
+
+                switch (decodeResult)
+                {
+                    case (MessageCodec::DECODE_RESULT_REBOOT_REQ_DL_MSG):
+                    {
+                        success = handleRebootReqDlMsg (dlMsg.rebootReqDlMsg.devModeOnNotOff);
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_SERIAL_NUMBER_GET_REQ_DL_MSG):
+                    {
+                        success = handleSerialNumberGetReqDlMsg();
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_READING_INTERVAL_SET_REQ_DL_MSG):
+                    {
+                        success = handleReadingIntervalSetReqDlMsg (dlMsg.readingIntervalSetReqDlMsg.readingIntervalSeconds);
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_READING_INTERVAL_GET_REQ_DL_MSG):
+                    {
+                        success = handleReadingIntervalGetReqDlMsg();
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_GPIO_SET_REQ_DL_MSG):
+                    {
+                        success = handleGpioSetReqDlMsg (&(dlMsg.gpioSetReqDlMsg.gpioState));
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_GPIO_GET_REQ_DL_MSG):
+                    {
+                        success = handleGpioGetReqDlMsg(dlMsg.gpioGetReqDlMsg.gpio);
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_LED_SET_REQ_DL_MSG):
+                    {
+                        success = handleLedSetReqDlMsg (dlMsg.ledSetReqDlMsg.onNotOff);
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_LED_GET_REQ_DL_MSG):
+                    {
+                        success = handleLedGetReqDlMsg();
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_FLASH_SET_REQ_DL_MSG):
+                    {
+                        success = handleFlashSetReqDlMsg (dlMsg.flashSetReqDlMsg.onNotOff);
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_FLASH_GET_REQ_DL_MSG):
+                    {
+                        success = handleFlashGetReqDlMsg ();
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_FAILURE):
+                    {
+                        success = false;
+                        assertAlways (DEBUG_SOS_PROTOCOL_PROBLEM, "Message decode failure.");
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_INPUT_TOO_SHORT):
+                    {
+                        success = false;
+                        assertAlways (DEBUG_SOS_PROTOCOL_PROBLEM, "Message decode failure due to input too short.");
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_OUTPUT_TOO_SHORT):
+                    {
+                        success = false;
+                        assertAlways (DEBUG_SOS_PROTOCOL_PROBLEM, "Message decode failure due to output buffer too short.");
+                    }
+                    break;
+                    case (MessageCodec::DECODE_RESULT_UNKNOWN_MSG_ID):
+                    {
+                        success = false;
+                        assertAlways (DEBUG_SOS_PROTOCOL_PROBLEM, "Unknown message ID.");
+                    }
+                    break;
+                    default:
+                    {
+                        success = false;
+                        assertAlways (DEBUG_SOS_PROTOCOL_PROBLEM, "Unknown decode result: 0x%x.", decodeResult);
+                    }
+                    break;
+                }
+            }
+            pEntry->inUse = false;  // Done with this one now
+        }
+        pEntry = pEntry->pNextEntry; // Move to the next entry
+    }
+
+    freeUnusedRecvDatagrams();
+
+    return success;
+}
+
+#ifdef C027N_USE_SOFT_RADIO
+  //  SoftModem should be connected to header pins 0 (Rx) and 1 (Tx)
+  MDMSerial gNeulSoftRadio (D1, D0, 57600, NC, NC);
+#else
+  // When compiling under GCC off-line, this works.
+  // However, when building under the on-line IDE
+  // it seems one has to define MDMSerial using the D1 and D0
+  // pins _outside_ a function, static is just not good enough,
+  // whereas we must define MDMSerial using MDMTXD and MDMRXD
+  // _inside_ a function since it depends on some initialisation
+  // that is performed just before entry to main.
+  // Hence the lines above.  But I'm leaving this here to
+  // show how it is meant to work.
+
+  // Create the Neul modem instance
+  static MDMSerial *getMDMSerial(void)
+  {
+  //#ifdef C027N_USE_SOFT_RADIO
+  //    printf ("\nC027N_USE_SOFT_RADIO is defined.\n");
+  //    printf ("The on-board modem will be ignored.\n");
+  //    printf ("SoftModem should be connected to header pins 0 (Rx) and 1 (Tx).\n");
+  //    static MDMSerial gNeul (D1, D0, 57600, NC, NC);
+  //#else
+      static MDMSerial gNeul (MDMTXD, MDMRXD, 57600, NC, NC);
+  //#endif
+      return &gNeul;
+  }
+#endif
+
+// ----------------------------------------------------------------
+// PUBLIC FUNCTIONS
+// ----------------------------------------------------------------
+int realMain (uint8_t * pReserve)
+{
+    bool success = false;
+
+    Serial pc (USBTX, USBRX);
+
+    pc.baud (PC_BAUD_RATE);
+
+    // Use pReserve to stop any attempts by the compiler to get rid of it
+    printf ("Reserved 0x%08lX-0x%08lX for IAP stack.\n", (long unsigned int) pReserve, (long unsigned int) (pReserve + SIZE_STACK_FOR_IAP - 1));
+
+    printf ("\n%s revision details:\n", __FILE__);
+    printf ("%s (European time).\n", FILE_DATETIME);
+    printf ("%s, %s.\n\n", FILE_REV, FILE_CL);
+
+    printf ("This build will still run if no water meter is connected.\n");
+    printf ("The water volume and serial number will be garbage.\n");
+
+    // Instantiate the Neul modem class
+#ifdef C027N_USE_SOFT_RADIO
+    pgNeul = &gNeulSoftRadio;
+#else
+    pgNeul = getMDMSerial();
+#endif
+
+    if (pgNeul != NULL)
+    {
+        // Initialise main
+        success = init();
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_GENERIC_FAILURE, "Unable to instantiate modem class.");
+    }
+
+    if (success)
+    {
+        // Initialise the water meter
+        printf ("Initialising water meter...\n");
+        //gWaterMeter.setDebugOn(true);
+        gWaterMeter.init();
+
+        // Initialise the Neul module
+        printf ("Initialising module...\n");
+        pgNeul->setDebug(3);  // Normally set to 2, set to 3 for maximum debug
+        success = pgNeul->init();
+
+        if (success)
+        {
+            // Allow the user to configure the module
+            configureModule();
+
+            if (gModulePhase > MODULE_PHASE_1)
+            {
+                // Wait for registration to complete but
+                // only if phase 2 or higher as the CONNECT
+                // string was never returned in earlier versions
+                printf ("Waiting for device to register...\n");
+                success = waitReg (WAIT_REG_S);
+            }
+
+            if (success)
+            {
+                // Prepare the initial messages in a datagram
+                success = queueInitialDatagram();
+
+                while (success)
+                {
+                    Timer timer;
+                    uint32_t readingIntervalSeconds = readNvContext()->readingIntervalSeconds;
+
+                    timer.start();
+
+                    // Prepare the periodic messages in a datagram
+                    success = queuePeriodicDatagram ();
+
+                    // Now do sends and then receives for the interval
+                    printf ("\nSending and then receiving datagrams for %ld seconds...\n", readingIntervalSeconds);
+                    while ((timer.read() < readingIntervalSeconds) && success)
+                    {
+                        success = sendAndReceive() && processReceivedDatagrams();
+                        printf (".");
+                    }
+                    printf ("\n");
+                }
+
+                assertAlways (DEBUG_SOS_GENERIC_FAILURE, "Exited main loop with success = false.");
+            }
+            else
+            {
+                assertAlways (DEBUG_SOS_NETWORK_SEND_PROBLEM, "Registration failed.");
+            }
+        }
+        else
+        {
+            assertAlways (DEBUG_SOS_AT_COMMAND_PROBLEM, "Modem initialisation failed.");
+        }
+
+        // Tidy up
+        deInit();
+    }
+    else
+    {
+        assertAlways (DEBUG_SOS_GENERIC_FAILURE, "Initialisation failed.");
+    }
+
+    return 0;
+}
+
+// This is necessary as the IAP functions use the top SIZE_STACK_FOR_IAP bytes of
+// RAM for their own purposes
+int main()
+{
+    uint8_t reserve[SIZE_STACK_FOR_IAP];
+
+    return realMain (reserve);
+}
+
+// End Of File