RAK3172 P2P SYNCWORD issue

LPWAN Modules / EVBs RAK3172
1

I am using the 2 x RAK3172 in p2p mode. I am using a terminal program to test (no code involved). I can send data back and forth.
When I change the syncword from the default, if it contains a ‘0’ character, I don’t get a RX event at the receiving end.

The new syncword is accepted (both devices) -

AT+SYNCWORD=?
AT+SYNCWORD=0017\r\nOK\r\n

As soon as I change the syncword so that there are no zeros, the packets appear.

Is this expected behaviour? or am I missing something?

2

Welcome to RAK forum @nigel ,

Can you please share me your P2P settings, payload you try to send as well as the SYNC word? I can try to replicate your setup.

On my testing, 0x0011 and 0x0017 works ok without any issues.

image

My LoRa P2P setting is AT+P2P=915000000:7:0:0:20:14 and uses RAK3172 Evaluation Board.

3

Hi, thanks for the reply. When I discovered which parameter that was causing the issue, I reset the modules using ATR and set the work mode to P2P - here is the output from querying the p2p commands using a python script

b'\r\nRAKwireless RAK3172\r\n------------------------------------------------------\r\nVersion: RUI_4.0.6_RAK3172-E\r\nCurrent Work Mode: LoRaWAN.\r\n'

b'OK\r\nRAKwireless RAK3172\r\n------------------------------------------------------\r\nVersion: RUI_4.0.6_RAK3172-E\r\nCurrent Work Mode: LoRa P2P.\r\n'

b'OK\r\n'

AT+UID=?
b'AT+UID=203134573941500500380012\r\nOK\r\n'

AT+CLIVER=?
b'AT+CLIVER=1.5.11\r\nOK\r\n'

AT+VER=?
b'AT+VER=RUI_4.0.6_RAK3172-E\r\nOK\r\n'

AT+LPM=?
b'AT+LPM=0\r\nOK\r\n'

AT+NWM=?
b'AT+NWM=0\r\nOK\r\n'

AT+PFREQ=?
b'AT+PFREQ=867100000\r\nOK\r\n'

AT+PSF=?
b'AT+PSF=7\r\nOK\r\n'

AT+PBW=?
b'AT+PBW=0\r\nOK\r\n'

AT+PCR=?
b'AT+PCR=0\r\nOK\r\n'

AT+PPL=?
b'AT+PPL=200\r\nOK\r\n'

AT+PTP=?
b'AT+PTP=5\r\nOK\r\n'

AT+PBR=?
b'AT_MODE_NO_SUPPORT\r\n'

AT+PFDEV=?
b'AT_MODE_NO_SUPPORT\r\n'

AT+PSEND=?
b'AT_PARAM_ERROR\r\n'

AT+CAD=?
b'AT+CAD=0\r\nOK\r\n'

AT+PRECV=?
b'P2P_RX_OFF\r\nOK\r\n'

AT+ENCRY=?
b'AT+ENCRY=0\r\nOK\r\n'

AT+ENCKEY=?
b'AT+ENCKEY=00000000000000000000000000000000\r\nOK\r\n'

AT+PCRYPT=?
b'AT_COMMAND_NOT_FOUND\r\n'

AT+PKEY=?
b'AT_COMMAND_NOT_FOUND\r\n'

AT+CRYPIV=?
b'AT+CRYPIV=00000000000000000000000000000000\r\nOK\r\n'

AT+P2P=?
b'AT+P2P=867100000:7:0:0:200:5\r\nOK\r\n'

AT+IQINVER=?
b'AT+IQINVER=0\r\nOK\r\n'

AT+SYNCWORD=?
b'AT+SYNCWORD=1424\r\nOK\r\n'

AT+RFFREQUENCY=?
b'AT+RFFREQUENCY=867100000\r\nOK\r\n'

AT+TXOUTPUTPOWER=?
b'AT+TXOUTPUTPOWER=5\r\nOK\r\n'

AT+BANDWIDTH=?
b'AT+BANDWIDTH=0\r\nOK\r\n'

AT+SPREADINGFACTOR=?
b'AT+SPREADINGFACTOR=7\r\nOK\r\n'

AT+CODINGRATE=?
b'AT+CODINGRATE=0\r\nOK\r\n'

AT+PREAMBLELENGTH=?
b'AT+PREAMBLELENGTH=200\r\nOK\r\n'

AT+SYMBOLTIMEOUT=?
b'AT+SYMBOLTIMEOUT=0\r\nOK\r\n'

AT+FIXLENGTHPAYLOAD=?
b'AT+FIXLENGTHPAYLOAD=0\r\nOK\r\n'

To perform the test I used Realterm to send the strings - I used AT+PRECV=65533 to put both units in listening mode. Sorry I don’t have copy of the string, it was a modbus request formatted for the RAK. Sorry I didn’t capture the replies from the modules.

4

I am not sure how I can help further.

  1. The sync word you use seems ok AT+SYNCWORD=1424
  2. Your FW version is too old. I recommend you update to the latest one.

More info about SYNC word.

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5

Hi, thanks for your reply. Re. SYNC word, that makes sense and covers my issue.
Re. firmware, where can I find the latest version with the changelog to see if it applies to P2P mode?

6

You can check FW and change logs here - Release Versions | RAKwireless Documentation Center

7

Hi
Looking at the firmware available, which version of the 3172 do I use? I have the 3172 not the T variant and I’m not using the E evaluation board.

8

For standard RAK3172, you must use the RAK3172 Evaluation Board.