On Fri, Jun 26, 2009 at 7:08 AM, sofia
aparicio<[email protected]> wrote:
>
>
> Hello,
>
> I would like to know what do I need to do to send and receive a message
> using the protocols of the Route library. Do I need to asociate every
> TOS_Msg with a TOS_MHopMsg? In Surge example they do the following:
>
> if (pReading = (SurgeMsg *)call Send.getBuffer(&gMsgBuffer,&Len)) {
> pReading->type = SURGE_TYPE_SENSORREADING;
> pReading->parentaddr = call RouteControl.getParent();
> pReading->reading = gSensorData;
> call Send.send(&gMsgBuffer,sizeof(SurgeMsg)));
> }
>
> I have seen the code of these function but I do not understand what are they
> doing.
>
> command void *Send.getBuffer[uint8_t id](TOS_MsgPtr pMsg, uint16_t* length)
> {
> TOS_MHopMsg *pMHMsg = (TOS_MHopMsg *)pMsg->data;
> *length = TOSH_DATA_LENGTH - offsetof(TOS_MHopMsg,data);
> return (&pMHMsg->data[0]);
> }
getBuffer returns a pointer to an area in the packet buffer where you
can put your application payload.
>
> command result_t Send.send[uint8_t id](TOS_MsgPtr pMsg, uint16_t
> PayloadLen) {
> uint16_t usMHLength = offsetof(TOS_MHopMsg,data) + PayloadLen;
> if (usMHLength > TOSH_DATA_LENGTH) {
> return FAIL;
> }
> //dbg(DBG_ROUTE,"MHop: send\n");
> call RouteSelect.initializeFields(pMsg,id);
> if (call RouteSelect.selectRoute(pMsg,id) != SUCCESS) {
> return FAIL;
> }
> //dbg(DBG_ROUTE,"MHop: out pkt 0x%x\n",((TOS_MHopMsg
> *)pMsg->data)->seqno);
> if (call SendMsg.send[id](pMsg->addr, usMHLength, pMsg) != SUCCESS) {
> return FAIL;
> }
> return SUCCESS;
> }
When you call this function, the Route library takes the
responsibility for sending the packet after making sure that the
packet is not too big, etc.
- om_p
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