myapp_ex04a.c

This network protcol stack,it is very strong and powerful!

/******************************************************************************
*   MyApp_Ex01.c  - Initialization and main loop. 
*   MyApp_Ex02.c  - Energy Detection Scan
*   MyApp_Ex03a.c - A PAN Coordinator is started 
*   MyApp_Ex03b.c - Device locates coordinator using Active Scan 
* = MyApp_Ex04a.c - Coordinator responds to an Associate request = This file ==
*   MyApp_Ex04b.c - Device Associates to the PAN coordinator
*   MyApp_Ex05a.c - Coordinator receives data from device
*   MyApp_Ex05b.c - Device sends direct data to the coordinator
*   MyApp_Ex06a.c - Coordinator sends indirect data to device
*   MyApp_Ex06b.c - Device polls for data from the coordinator
*   MyApp_Ex07a.c - Coordinator starts a beaconed network
*   MyApp_Ex07b.c - Device receives data using automatic polling
*   MyApp_Ex08a.c - Coordinator uses security
*   MyApp_Ex08b.c - Device uses security
*
* This demo application builds on MyApp_Ex03a.c. In Ex03a it was demonstrated
* how to start a PAN coordinator. In the present example we will enable the 
* coordinator to respond to associate requests from devices.
*
* Associations are used for making a logical connection between devices and
* coordinators. One advantage of associations is that the communication can be
* performed using 2 byte addresses instead of 8 byte addresses. The benefit of
* this is longer battery life since less power is required for the radio.
*
* It is the coordinator that assigns short addresses to devices wishing to
* associate. The devices do so by sending out an Associate Request command.
* On the coordinator the command becomes an Associate Indication at the 
* network/application layer which then must select a unique short address for
* the new device. The network or application layer of the coordinator accepts
* the associate request by sending an Associate Response message to the MLME.
* When the MLME has sent the Associate Response to the device, it will send
* an MLME-Comm-Status Indication to the network or application layer with the
* status code for the transmission of the response. In this example we ignore
* the MLME-Comm-Status Indication to keep the code as simple as possible.
* 
* Some devices may chose not to request a short address. In such cases, the
* coordinator must assign the address 0xfffe to the device meaning that it
* is associated, but that the devices long address is used in every
* communication between the device and coordinator.
*
* The steps required for responding to an Associate Request are:
* 1) Receive an Associate Indication message.
* 2) Determine if we want or are able to accept the Associate Request.
* 3) Send an Associate Response with either gSuccess_c or an error code,
*    and the short address if any was assigned.
*
* Step 1-3 are all performed in the 'stateListen' state.
*
******************************************************************************/

#include "802_15_4.h" /* Include everything related to the 802.15.4 interface*/
#include "Uart.h"     /* Defines the interface of the demo UART. */
#include "ToolBox.h"  /* Defines for memcpy, memcmp. */

/* Defines the channels to scan. Each bit represents one channel. Use
   0x07FFF800 to scan all 16 802.15.4 channels in the 2.4GHz band. */
#define SCAN_CHANNELS 0x07FFF800

/* Forward declarations of helper functions */
uint8_t App_StartScan(uint8_t scanType);
void    App_HandleScanEdConfirm(nwkMessage_t *pMsg);
uint8_t App_StartCoordinator(void);
uint8_t App_HandleMlmeInput(nwkMessage_t *pMsg);
uint8_t App_SendAssociateResponse(nwkMessage_t *pMsgIn);
uint8_t App_WaitMsg(nwkMessage_t *pMsg, uint8_t msgType);


/* The various states of the application state machine. */
enum {
  stateInit,
  stateScanEdStart,
  stateScanEdWaitConfirm,
  stateStartCoordinator,
  stateStartCoordinatorWaitConfirm,
  stateListen,
  stateTerminate
};

/* Error codes */
enum {
  errorNoError,
  errorWrongConfirm,
  errorNotSuccessful,
  errorNoMessage,
  errorAllocFailed,
  errorInvalidParameter,
  errorNoScanResults
};

/* The current state of the applications state machine */
uint8_t state;

/* The status parameter of the latest confirm message from the MLME */
uint8_t confirmStatus;

/* The current logical channel (frequency band) */
uint8_t logicalChannel;

/* These byte arrays stores an associated
   devices long and short addresses. */
uint8_t deviceShortAddress[2];
uint8_t deviceLongAddress[8];

/* We want the coordinators short address to be 0xCAFE. */
const uint8_t shortAddress[2] = { 0xFE, 0xCA };

/* PAN ID is 0xBEEF */ 
const uint8_t panId[2] = { 0xEF, 0xBE };

/* Application input queues */
anchor_t mMlmeNwkInputQueue;

/* Application Main Loop */
void main(void)
{ 
  /* Pointer for storing the messages from MLME */
  void *pMsgIn;
  /* Stores the error/success code returned by some functions. */
  uint8_t ret;
  /* return value of Mlme_Main() - not used yet */
  uint8_t macStatus;
  
  /* Initialize variables */
  state = stateInit;
 
  /* Prepare input queues.*/
  MSG_InitQueue(&mMlmeNwkInputQueue);

  /* Execute the application state machine */    
  while(state < stateTerminate)
  {
    /* Preset return code to contain the success code */
    ret = errorNoError;
    
    /* Try to get a message from MLME */
    if(MSG_Pending(&mMlmeNwkInputQueue))
      pMsgIn = MSG_DeQueue(&mMlmeNwkInputQueue);
    else
      pMsgIn = NULL;
      
    switch(state)
    {
    case stateInit:
      /* Initialize the UART so that we can print out status messages */
      Uart_Init();
      /* Initialize the 802.15.4 stack */
      Init_802_15_4();
      /* Goto Energy Detection state. */
      state = stateScanEdStart;

      /* Print a welcome message to the UART */
      Uart_Print("The Myapp_Ex04a demo application is initialized and ready.\n\n");
      break;
      
    case stateScanEdStart:
      /* Start the Energy Detection scan, and goto wait for confirm state. */
      Uart_Print("Initiating the Energy Detection Scan\n");
      ret = App_StartScan(gScanModeED_c);
      if(ret == errorNoError)
      {
        state = stateScanEdWaitConfirm;
      }
      break;
      
    case stateScanEdWaitConfirm:
      /* Stay in this state until the MLME Scan confirm message arrives,
         and has been processed. Then goto Start Coordinator state. */
      ret = App_WaitMsg(pMsgIn, gNwkScanCnf_c);
      if(ret == errorNoError)
      {
        /* Process the ED scan confirm. The logical
           channel is selected by this function. */
        App_HandleScanEdConfirm(pMsgIn);
        state = stateStartCoordinator;
      }
      break;

    case stateStartCoordinator:
      /* Start up as a PAN Coordinator on the selected channel. */
      Uart_Print("\nStarting as PAN coordinator on channel 0x");
      Uart_PrintHex(&logicalChannel, 1, FALSE);
      Uart_Print("\n");
      ret = App_StartCoordinator();
      if(ret == errorNoError)
      {
        /* If the Start request was sent successfully to
           the MLME, then goto Wait for confirm state. */
        state = stateStartCoordinatorWaitConfirm;
      }
      break; 

    case stateStartCoordinatorWaitConfirm:
      /* Stay in this state until the Start confirm message
         arrives, and then goto the Listen state. */
      ret = App_WaitMsg(pMsgIn, gNwkStartCnf_c);
      if(ret == errorNoError)
      {
        Uart_Print("Started the coordinator with PAN ID 0x");
        Uart_PrintHex((uint8_t *)panId, 2, 0);
        Uart_Print(", and short address 0x");
        Uart_PrintHex((uint8_t *)shortAddress, 2, 0);
        Uart_Print(".\n");
        state = stateListen;
      }
      break; 
      
    case stateListen:
      /* Stay in this state forever. Handles associate, disassociate etc. */
      ret = App_HandleMlmeInput(pMsgIn);
      break;
    }
    
    if(pMsgIn)
    {
      /* Messages from the MLME must always be freed. */
      MSG_Free(pMsgIn);
    }
    
    /* Call the MAC main function continuously. */
    macStatus = Mlme_Main();
  }
}


/******************************************************************************
* The App_StartScan(scanType) function will start the scan process of the
* specified type in the MAC. This is accomplished by allocating a MAC message,
* which is then assigned the desired scan parameters and sent to the MLME
* service access point.
* The function may return either of the following values:
*   errorNoError:          The Scan message was sent successfully.
*   errorInvalidParameter: The MLME service access point rejected the
*                          message due to an invalid parameter.
*   errorAllocFailed:      A message buffer could not be allocated.
*
******************************************************************************/
uint8_t App_StartScan(uint8_t scanType)
{
  mlmeMessage_t *pMsg;
  mlmeScanReq_t *pScanReq;

  Uart_Print("Sending the MLME-Scan Request message to the MAC...");

  /* Allocate a message for the MLME (We should check for NULL). */
  pMsg = MSG_AllocType(mlmeMessage_t);
  if(pMsg != NULL)
  {
    /* This is a MLME-START.req command */
    pMsg->msgType = gMlmeScanReq_c;
    /* Create the Start request message data. */
    pScanReq = &pMsg->msgData.scanReq;
    /* gScanModeED_c, gScanModeActive_c, gScanModePassive_c, or gScanModeOrphan_c */
    pScanReq->scanType = scanType;
    /* ChannelsToScan & 0xFF - LSB, always 0x00 */
    pScanReq->scanChannels[0] = (uint8_t)((SCAN_CHANNELS)     & 0xFF);
    /* ChannelsToScan>>8 & 0xFF  */
    pScanReq->scanChannels[1] = (uint8_t)((SCAN_CHANNELS>>8)  & 0xFF);
    /* ChannelsToScan>>16 & 0xFF  */
    pScanReq->scanChannels[2] = (uint8_t)((SCAN_CHANNELS>>16) & 0xFF);
    /* ChannelsToScan>>24 & 0xFF - MSB */
    pScanReq->scanChannels[3] = (uint8_t)((SCAN_CHANNELS>>24) & 0xFF);
    /* Duration per channel 0-14 (dc). T[sec] = (16*960*((2^dc)+1))/1000000.
       A scan duration of 5 on 16 channels approximately takes 8 secs. */
    pScanReq->scanDuration = 5;
    
    /* Send the Scan request to the MLME. */
    if(MSG_Send(NWK_MLME, pMsg) == gSuccess_c)
    {
      Uart_Print("Done\n");
      return errorNoError;
    }
    else
    {
      Uart_Print("Invalid parameter!\n");
      return errorInvalidParameter;
    }
  }
  else
  {
    /* Allocation of a message buffer failed. */
    Uart_Print("Message allocation failed!\n");
    return errorAllocFailed;
  }
}


/******************************************************************************
* The App_HandleScanEdConfirm(nwkMessage_t *pMsg) function will handle the
* ED scan confirm message received from the MLME when the ED scan has completed.
* The message contains the ED scan result list. This function will search the
* list in order to select the logical channel with the least energy. The
* selected channel is stored in the global variable called 'logicalChannel'.
*
******************************************************************************/
void App_HandleScanEdConfirm(nwkMessage_t *pMsg)
{