- //Only should transmit length of one more than the reported
- // length of the frame, which holds the length byte:
- txdata(app,verb,cmddata[0]+1);
+ CLRSS;
+ ccspitrans8(CCSPI_RXFIFO | 0x40);
+ // Grab the length.
+ cmddata[0]=ccspitrans8(0x00);
+
+ //Read the header first.
+ for(i=1;i<cmddata[0]+1 && i<0x11;i++)
+ cmddata[i]=ccspitrans8(0x00);
+ SETSS;
+
+ //Is the frame encrypted?
+ if(cmddata[1]&BIT3){
+ //Copy the sequence number to the Nonce.
+
+
+ //Decrypt the rest of the packet.
+ CLRSS; ccspitrans8(CCSPI_SRXDEC); SETSS;
+
+ //Wait for decryption to complete.
+ while(!FIFO);
+
+ }
+
+
+ //Get the packet, which is now decrypted in position.
+ CLRSS;
+ ccspitrans8(CCSPI_RXFIFO | 0x40);
+ //ccspitrans8(0x3F|0x40);
+
+
+ /* This reads too far on some CC2420 revisions, but on others it
+ works fine. It probably has to do with whether FIFO drops
+ before or after the SPI clocking.
+
+ A software fix is to reset the CC2420 between packets. This
+ works, but a better solution is desired.
+ */
+ for(;i<cmddata[0]+1;i++)
+ cmddata[i]=ccspitrans8(0x00);
+ SETSS;
+
+ //Only forward a packet if the length is legal.
+ if(cmddata[0]&0x80) i=0;
+ txdata(app,verb,i);