myapp_ex06b.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 
*   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 === This file ==
*   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 upon MyApp_Ex05b.c which demonstrated how
* to send data to a coordinator. In this demo application we will receive data
* from the coordinator using poll requests.
*
* In 802.15.4 most communications are driven by the devices in a network. They
* are typically battery powered and need to be able to control the data flow.
* in order to optimize battery life. This is done by polling for data from
* the coordinator, and transmitting data directly to the coordinator. The
* coordinator only sends data to a device when it knows it is listening, i.e. 
* when the device has requested data.
*
* This example will demonstrate indirect data from the coordinator to the 
* device. Data sent to the device is not transmitted immediately but put into 
* a queue in the coordinators MAC. Here it resides until the device sends a
* poll request. The poll request is initiated by the network or application
* layer on the device.
*
* To test the data transfer from the coordinator to the device, both should be
* connected to a PC with an RS232 terminal at 19200bps, 8N1. When sending an
* ASCII file (send as text) from the coordinators terminal, the file will be 
* printed to the terminal connected to the device. It resembles a bidirectional
* wireless RS232 cable replacement (though, without error checking and flow 
* control in this simple example).
*
* The steps required for receiving a data packet from the coordinator is:
* 1) We should have an association to the coordinator we want to receive from.
* 2) Allocate an MLME-Poll Request message and fill in the coordinator
*    information gained during Active Scan. Send the message to the MLME.
* 3) Wait for MCPS-Data Indication message. It contains the data from the
*    coordinator.
*
* Step 1 has been covered in previous demo applications. Step 2 is performed
* by the App_TransmitUartData() function while step 3 is performed by the
* App_HandleMcpsInput() function. Both are called outside the applications  
* state machine.
*
******************************************************************************/

#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 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

/* Maximum number of outstanding packets */
#define MAX_PENDING_DATA_PACKETS 2

/* Default size of data payload in MCPS-Data.request.
   The length has no real meaning since MCPS-Data.requests
   are always sent in one-size buffers big enough to hold
   a maximum length data frame. */
#define DEFAULT_DATA_LENGTH 20

/* These constants are used for specifying the poll interval. The actual time
   in seconds is calculated as: T(x) = x*(65536/16000000) or ~ x/244 */
/* The slow polling interval is used if the coordinator
   had no data last time we polled. */
#define POLL_INTERVAL_SLOW 200 /* ~0.82 secs */
/* The fast polling interval is used if the coordinator had data last time we
   polled, thus we increase the band-width while data is available. */
#define POLL_INTERVAL_FAST 20 /* ~0.082 secs */

/* Forward declarations of helper functions */
uint8_t App_StartScan(uint8_t scanType);
uint8_t App_HandleScanActiveConfirm(nwkMessage_t *pMsg);
uint8_t App_WaitMsg(nwkMessage_t *pMsg, uint8_t msgType);
uint8_t App_SendAssociateRequest(void);
void    App_HandleAssociateConfirm(nwkMessage_t *pMsg);
uint8_t App_HandleMlmeInput(nwkMessage_t *pMsg);
void    App_HandleMcpsInput(mcpsToNwkMessage_t *pMsgIn);
void    App_TransmitUartData(void);
void    App_ReceiveUartData(void);

/* All states in the applications state machine */
enum {
  stateInit,
  stateScanActiveStart,
  stateScanActiveWaitConfirm,
  stateAssociate,
  stateAssociateWaitConfirm,
  stateListen,
  stateTerminate
};

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


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

/* Information about the PAN we are part of */
panDescriptor_t coordInfo;

/* This is either the short address assigned by the PAN coordinator
   during association, or our own extended MAC address. */
uint8_t myAddress[8];
/* The devices address mode. If 2, then myAddress contains the short
   address assigned by the PAN coordinator. If 3, then myAddress is
   equal to the extended address. */
uint8_t myAddrMode;

/* Data request packet for sending UART input to the coordinator */
nwkToMcpsMessage_t *pPacket;

/* The MSDU handle is a unique data packet identifier */
uint8_t msduHandle;

/* Number of pending data packets */
uint8_t numPendingPackets;

/* Signals that an MLME-Poll request is pending, and that we must wait for 
   the MLME-Poll confirm message before sending the next poll request. */
bool_t waitPollConfirm;

/* Time between MLME-Poll requests */
uint8_t pollInterval;

/* Application input queues */
anchor_t mMlmeNwkInputQueue;
anchor_t mMcpsNwkInputQueue;


/* Application Main Loop */
void main(void)
{ 
  /* Pointer for storing the messages from MLME, MCPS, and ASP. */
  void *pMsgIn;
  /* Stores the status code returned by some functions. */
  uint8_t rc;
  /* return value of Mlme_Main() - not used yet */
  uint8_t macStatus;
  
  /* Initialize variables */
  state = stateInit;

  /* Prepare input queues.*/
  MSG_InitQueue(&mMlmeNwkInputQueue);
  MSG_InitQueue(&mMcpsNwkInputQueue);

  /* Execute the application state machine */    
  while(state < stateTerminate)
  {
    /* Preset error to contain the success code */
    rc = 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 = stateScanActiveStart;
      /* Reset number of pending packets */
      numPendingPackets = 0;
      /* Allow sending a poll request */
      waitPollConfirm = FALSE;

      /* Print a welcome message to the UART */
      Uart_Print("The Myapp_Ex06b demo application is initialized and ready.\n\n");
      break;
      
    case stateScanActiveStart:
      /* Start the Active scan, and goto wait for confirm state. */
      Uart_Print("Start scanning for a PAN coordinator\n");
      rc = App_StartScan(gScanModeActive_c);
      if(rc == errorNoError)
      {
        state = stateScanActiveWaitConfirm;
      }
      break;
      
    case stateScanActiveWaitConfirm:
      /* Stay in this state until the Scan confirm message
         arrives, and then goto the associate state. */
         
      /* ALWAYS free the beacon frame contained in the beacon notify indication.*/
      rc = App_WaitMsg(pMsgIn, gNwkBeaconNotifyInd_c);
      if(rc == errorNoError) {
        MSG_Free(((nwkMessage_t *)pMsgIn)->msgData.beaconNotifyInd.pBufferRoot);
        Uart_Print("Received an MLME-Beacon Notify Indication\n");
      }
      
      /* Handle the Scan Confirm message. */
      rc = App_WaitMsg(pMsgIn, gNwkScanCnf_c);
      if(rc == errorNoError)
      {
        rc = App_HandleScanActiveConfirm(pMsgIn);
        if(rc == errorNoError)
        {
          Uart_Print("Found a coordinator with the following properties:\n");
          Uart_Print("----------------------------------------------------");
          Uart_Print("\nAddress...........0x"); Uart_PrintHex(coordInfo.coordAddress, coordInfo.coordAddrMode == gAddrModeShort_c ? 2 : 8, 0);
          Uart_Print("\nPAN ID............0x"); Uart_PrintHex(coordInfo.coordPanId, 2, 0);
          Uart_Print("\nLogical Channel...0x"); Uart_PrintHex(&coordInfo.logicalChannel, 1, 0);
          Uart_Print("\nBeacon Spec.......0x"); Uart_PrintHex(coordInfo.superFrameSpec, 2, 0);
          Uart_Print("\nLink Quality......0x"); Uart_PrintHex(&coordInfo.linkQuality, 1, 0);
          Uart_Print("\n\n");

          state = stateAssociate;
        }
        else
          Uart_Print("Scan did not find a suitable coordinator\n");
      }
      break;

    case stateAssociate:
      /* Associate to the PAN coordinator */
      Uart_Print("Associating to PAN coordinator on channel 0x");
      Uart_PrintHex(&(coordInfo.logicalChannel), 1, gPrtHexNewLine_c);
      rc = App_SendAssociateRequest();
      if(rc == errorNoError)
        state = stateAssociateWaitConfirm;
      break; 

    case stateAssociateWaitConfirm:
      /* Stay in this state until the Associate confirm message
         arrives, and then goto the Listen state. */
      rc = App_WaitMsg(pMsgIn, gNwkAssociateCnf_c);
      if(rc == errorNoError)
      {
        App_HandleAssociateConfirm(pMsgIn);
        state = stateListen;
        Uart_Print("Successfully associated with the coordinator.\n");
        Uart_Print("We were assigned the short address 0x");
        Uart_PrintHex(myAddress, myAddrMode == gAddrModeShort_c ? 2 : 8, 0);
        Uart_Print("\n\nReady to send and receive data over the UART.\n\n");
      }
      break; 
      
    case stateListen:
      /* Stay in this state forever. Handles poll confirm etc. */
      rc = App_HandleMlmeInput(pMsgIn);
      break;
    }
    
    if(pMsgIn)
      /* ALWAYS free messages from MLME */
      MSG_Free(pMsgIn);

    
    /* If we are associated then check MCPS queue and UART data buffer. */
    if(state == stateListen)
    {
      /* Get input from MCPS. */
      if(MSG_Pending(&mMcpsNwkInputQueue))
      {
        pMsgIn = MSG_DeQueue(&mMcpsNwkInputQueue);
        App_HandleMcpsInput(pMsgIn);
        /* ALWAYS free messages from MCPS */
        MSG_Free(pMsgIn);
      }

      /* Check if the UART buffer has data to be sent. */
      App_TransmitUartData();

      /* Ask coordinator if it has any data for us. */
      App_ReceiveUartData();
    }
  
    /* Call the MAC main function. */
    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;
  }
}

/******************************************************************************