Spirit1 STack packet mode fixed length?

Scott Löhr · ‎2016-07-12

Posted on July 13, 2016 at 03:49

I am trying to configure for STack packet mode using fixed length packets with

4 preamble

4 sync

1 dst addr

1 src addr

0 control

80 data

2 crc

The total of above is 92, but data sheet says the length is only inclusive of addresses + data length. So what should I set the PCKTLEN1_BASE and PCKTLEN0_BASE registers? I tried setting to only 82, but auto ack is not working.

As an experiment, I set to use variable length mode and on Rx side, read RX_PCKT_LEN registers and see that they are set to 92.

Also to note, when configured for fixed length mode, on Rx side read RX_PCKT_LEN registers after getting a packet and they are ZERO.

#spirit1-stack-packet-fixed-len

Scott Löhr · ‎2016-07-14

Posted on July 14, 2016 at 20:10

I figured out a way to prove that 82 is the correct setting for the PCKTLEN registers by enabling the Rx filter options for CRC error, then when I Tx with length 92, the Rx rejects the packet with a CRC error (whereas before I was receiving the data payload as expected), and 82 passes the CRC of the Rx side.

Setting up this STack protocol has been challenging and the documents and sample apps very sparse on the full ''flow'' of getting it setup and working properly - it deserves a white paper summary.