Hi,

Hope this bit of code might help.

bRF_Timeout = false;
cRF_Time = cTick + 6;

cRX_RF_Byte = RCREG2;              //otherwise, get data byte from
Receive(1) buffer


switch (cRF_Mode)                  //RF RX state machine
       {                                       //must receive PREAMBLEe
followed immediately by SYNC to start reception
          case IDLE         :
                              if(cRX_RF_Byte = PREAMBLE)   //Is current byte
a PREAMBLE (0xAA) byte ?
                              {
                                cRF_Mode = GOT_PREAMBLE; //YES.. then switch
state to look for SYNC byte (0X33)
                              }
                              break;                     //NO... then ignore
and stay in IDLE mode

          case GOT_PREAMBLE :
                              if(cRX_RF_Byte == SYNC)    //is current byte
SYNC ?
                              {
                                cRF_Mode = RECEIVING;    //YES.. change
state to receive mode
                               cRX_RF_Ptr = 0;          //reset RX data
buffer pointer
                              }                          //NO... if another
PREAMBLE then stay in present state
                              else if(cRX_RF_Byte != 0xAA) cRF_Mode = IDLE;
//else reset state back to IDLE
                              break;

          case RECEIVING   :
                              cRX_RF_Buf[cRX_RF_Ptr] = cRX_RF_Byte;
//store byte into RF Receive buffer
                              cRX_RF_Ptr++;                         //point
to next location in buffer
                              if(cRX_RF_Ptr > 9)                    //fixed
length packet has been received
                              {
                                cRF_Mode = IDLE;                    //reset
state machine to IDLE mode
                                bReceived_RF_Packet = true;     //set flag
to indicate packet has arrived
                                break;
                              }
        }      //end of switch routine

The main program loop setes cRX_Mode = IDLE if timeout occurs due to
incomplete packet being receieved.

Regards

David Huisman

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