CRC_BAD when execute rak_common_for_gateway/lora/print_lora_log.sh

Hi,
I used RPI3B+ and RAK2245 to check LoRaWAN gateway functions.
The image I used is RAK2245&RAK831_based_on_Raspbian_OS_for_RPI3_V4.1.0_20191202.zip downloaded from RAKWireless download site.
The Node device I used is US915 module, it can join Multitech conduit 5.0.0-AEP firmwrae without problem.But it failed to join with RAK2245 gateway.
I captures packet with rak_common_for_gateway/lora/print_lora_log.sh but I always get CRC_BAD log as below:
[email protected]:/home/pi/rak_common_for_gateway/lora# ./print_lora_log.sh
loragw_pkt_logger: INFO: found global configuration file global_conf.json, trying to parse it
loragw_pkt_logger: INFO: global_conf.json does contain a JSON object named SX1301_conf, parsing SX1301 parameters
loragw_pkt_logger: INFO: lorawan_public 1, clksrc 1
loragw_pkt_logger: INFO: radio 0 enabled (type SX1257), center frequency 904300000, RSSI offset -166.000000, tx enabled 1, tx_notch_freq 0
loragw_pkt_logger: INFO: radio 1 enabled (type SX1257), center frequency 905000000, RSSI offset -166.000000, tx enabled 0, tx_notch_freq 0
loragw_pkt_logger: INFO: LoRa multi-SF channel 0 enabled, radio 0 selected, IF -400000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 1 enabled, radio 0 selected, IF -200000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 2 enabled, radio 0 selected, IF 0 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 3 enabled, radio 0 selected, IF 200000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 4 enabled, radio 1 selected, IF -300000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 5 enabled, radio 1 selected, IF -100000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 6 enabled, radio 1 selected, IF 100000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa multi-SF channel 7 enabled, radio 1 selected, IF 300000 Hz, 125 kHz bandwidth, SF 7 to 12
loragw_pkt_logger: INFO: LoRa standard channel enabled, radio 0 selected, IF 300000 Hz, 500000 Hz bandwidth, SF 8
loragw_pkt_logger: INFO: FSK channel 8 disabled
loragw_pkt_logger: INFO: global_conf.json does contain a JSON object named gateway_conf, parsing gateway parameters
loragw_pkt_logger: INFO: gateway MAC address is configured to 0000000000000000
loragw_pkt_logger: INFO: found local configuration file local_conf.json, trying to parse it
loragw_pkt_logger: INFO: local_conf.json does not contain a JSON object named SX1301_conf
loragw_pkt_logger: INFO: local_conf.json does contain a JSON object named gateway_conf, parsing gateway parameters
loragw_pkt_logger: INFO: gateway MAC address is configured to B827EBFFFE4422EF
loragw_pkt_logger: INFO: concentrator started, packet can now be received
loragw_pkt_logger: INFO: Now writing to log file pktlog_B827EBFFFE4422EF_20191127T034417Z.csv
------------------------log file name: ./pktlog_B827EBFFFE4422EF_20191127T034417Z.csv-----------------
---------------------------log------------------------------
“gateway ID”,“node MAC”,“UTC timestamp”,“us count”,“frequency”,“RF chain”,“RX chain”,“status”,“size”,“modulation”,“bandwidth”,“datarate”,“coderate”,“RSSI”,“SNR”,“payload”
“B827EBFFFE4422EF”,"",“2019-11-27 03:45:21.281Z”, 66827116, 905100000,1, 6,“CRC_BAD”, 16,“LORA”,125000,“SF7” ,"" ,-108,-10.5,“6657DA4D-6B87B604-55435A34-19EAB7CC”

What can I do to debug this issue?

Hello @billtsai01, Welcome to our community.

Is your rak2245 connected to a lora antenna?
Can you take a picture of your rak2245 like this?

Almost the same for me

“gateway ID”,“node MAC”,“UTC timestamp”,“us count”,“frequency”,“RF chain”,“RX chain”,“status”,“size”,“modulation”,“bandwidth”,“datarate”,“coderate”,“RSSI”,“SNR”,“payload”
“B827EBFFFE7F9480”,"",“2020-06-04 15:01:14.731Z”, 230249548, 867500000,0, 5,“CRC_BAD”, 20,“LORA”,125000,“SF7” ,"" ,-114,-10.8,“DF0CB947-F94CFD3F-4B9B5FFA-5DD458EB-C4FDF121”
“B827EBFFFE7F9480”,"",“2020-06-04 15:02:27.018Z”, 302535507, 868500000,1, 2,“CRC_BAD”,124,“LORA”,125000,“SF7” ,"" ,-113,-11.5,“420C30BB-17A0710D-297BFD10-A830F88A-4CDE53A0-2D4055DC-D510D205-55051B79-3CAC7EC2-E9C29905-BCE02DC1-54FD98AC-A7920403-BC5879C7-A91E64F1-90BE35CE-22E38D70-2A744401-64A0DFD1-953B7984-BEC3A0B5-3C519D5A-9579AA76-0EB16C0C-BA61C8D5-2B5FCA55-E9F182BB-F28BDE9D-AA79701E-2CE83533-3A28F447”
“B827EBFFFE7F9480”,"",“2020-06-04 15:03:14.493Z”, 349983740, 867100000,0, 3,“CRC_OK” , 14,“LORA”,125000,“SF12” ,“4/5”,-63, +7.2,“40028A7B-0080D207-01700E7C-FC94”
“B827EBFFFE7F9480”,"",“2020-06-04 15:03:38.081Z”, 373597859, 867100000,0, 3,“CRC_BAD”,122,“LORA”,125000,“SF7” ,“2/3”,-114,-11.0,“CB73ED6D-41E58EB5-4F0FB8F1-858B91F0-4645783D-0D82D76B-D171722D-00F5F9B2-3A4956C0-F4ED8057-D31013E3-E389A7BD-1C58766E-182097FA-E7E787AF-9D21461D-24DE3E9D-43E1C9A3-1556E630-7C24C3B6-A0DE9C18-F2A9DBAE-6FE35D8F-4AF97884-319C891C-E179D028-A4BF8430-7D8CF981-3A420FE9-A1BF0657-D3B4”
“B827EBFFFE7F9480”,"",“2020-06-04 15:03:40.390Z”, 375907981, 868300000,1, 8,“CRC_BAD”, 51,“LORA”,250000,“SF7” ,"" ,-108,-12.0,“FF98FB20-9496C877-39F385DC-169421BE-1ED21F0F-A790F0CD-5000170D-A6696188-CEB788D6-89C48D10-AFCC61C4-971B30A7-DCBAD5”

SF12-> CRC_OK
SF7-> CRC_BAD

Hello @Supermenteur
2020-06-05 09-53-23

I can’t see clearly from the picture, is the resistor connected at 915?

From the logs, it can be seen that both rssi and snr are worse at SF7. Can the transmission power of the node at SF7 be increased?

I’m running eu868. No resistor.
All my nodes are very close. Could it be an antenna issue?

No resistor?

Can you take a clear picture of that part?

I use RAK nodes to send data on SF7 and SF12 respectively(using the same power). RAK2245 is not connected to the antenna, they are about 1 meter apart.

I still suspect that your node may have too little transmit power.

This message at -63 dB RSSI makes it look like things actually do work.

When a node is extremely close to a gateway, sometimes there’s false reception on a channel other than the frequency actually transmitted on. Such bleedover will be much weaker and may have errors. Typically when running the actual packet forwarder the packet will also be received on the actual channel without error at the same time, so you might try the real packet forwarder and not this test script.

But also move the node further away from the gateway such that it isn’t overpowering the front end and only gets received on the actual transmit channel.

Hi
Do you mean that antenna of LoRa can be removed to do the test?
I saw from your web site that both LoRa and GPS antenna must be connected before power up RPi 3B+.
Connect antenna before powering up RP3B+

No. I mean, can you confirm if your nodes have the same transmit power in SF7 and SF12?Perhaps the node’s transmit power at SF12 is less.

You can refer to Chris’s suggestion to move the node further away from the gateway.