When the packet forwarder starts up:

pi@alphawan:~/lora/exec $ ./gps_pkt_fwd 

*** GPS Packet Forwarder for Lora Gateway ***

Version: 2.1.0

*** Lora concentrator HAL library version info ***

Version: 3.1.0; Options: ftdi;

***

INFO: Little endian host

INFO: found global configuration file global_conf.json, parsing it

INFO: global_conf.json does contain a JSON object named SX1301_conf, parsing SX1301 parameters

INFO: lorawan_public 1, clksrc 0

INFO: no configuration for tx gain lut 16

INFO: no configuration for tx gain lut 17

INFO: no configuration for tx gain lut 18

INFO: no configuration for tx gain lut 19

INFO: no configuration for tx gain lut 20

INFO: no configuration for tx gain lut 21

INFO: no configuration for tx gain lut 22

INFO: no configuration for tx gain lut 23

INFO: no configuration for tx gain lut 24

INFO: no configuration for tx gain lut 25

INFO: no configuration for tx gain lut 26

INFO: no configuration for tx gain lut 27

INFO: no configuration for tx gain lut 28

INFO: no configuration for tx gain lut 29

INFO: no configuration for tx gain lut 30

INFO: no configuration for tx gain lut 31

INFO: no configuration for tx gain lut 32

INFO: no configuration for tx gain lut 33

INFO: no configuration for tx gain lut 34

INFO: no configuration for tx gain lut 35

INFO: Configuring TX LUT with 16 indexes

INFO: radio 0 enabled (type SX1257), center frequency 868200000, RSSI offset -166.000000, tx enabled 1

INFO: radio 1 enabled (type SX1257), center frequency 869200000, RSSI offset -166.000000, tx enabled 0

INFO: Lora multi-SF channel 0>  radio 0, IF -100000 Hz, 125 kHz bw, SF 7 to 12

INFO: Lora multi-SF channel 1>  radio 0, IF 100000 Hz, 125 kHz bw, SF 7 to 12

INFO: Lora multi-SF channel 2>  radio 0, IF 300000 Hz, 125 kHz bw, SF 7 to 12

INFO: Lora multi-SF channel 3>  radio 1, IF -350000 Hz, 125 kHz bw, SF 7 to 12

INFO: Lora multi-SF channel 4>  radio 1, IF -150000 Hz, 125 kHz bw, SF 7 to 12

INFO: Lora multi-SF channel 5>  radio 1, IF 325000 Hz, 125 kHz bw, SF 7 to 12

INFO: Lora multi-SF channel 6 disabled

INFO: Lora multi-SF channel 7 disabled

INFO: Lora std channel> radio 0, IF 100000 Hz, 250000 Hz bw, SF 7

INFO: FSK channel> radio 0, IF 100000 Hz, 125000 Hz bw, 50000 bps datarate

INFO: global_conf.json does contain a JSON object named gateway_conf, parsing gateway parameters

INFO: gateway MAC address is configured to B827EBFFFE783077

INFO: server hostname or IP address is configured to "10.0.1.41"

INFO: upstream port is configured to "1680"

INFO: downstream port is configured to "1680"

INFO: downstream keep-alive interval is configured to 10 seconds

INFO: statistics display interval is configured to 30 seconds

INFO: upstream PUSH_DATA time-out is configured to 100 ms

INFO: packets received with a valid CRC will be forwarded

INFO: packets received with a CRC error will NOT be forwarded

INFO: packets received with no CRC will NOT be forwarded

INFO: GPS serial port path is configured to "/dev/ttyAMA0"

INFO: Reference latitude is configured to 0.000000 deg

INFO: Reference longitude is configured to 0.000000 deg

INFO: Reference altitude is configured to 0 meters

INFO: [main] TTY port /dev/ttyAMA0 open for GPS synchronization

INFO: [main] concentrator started, packet can now be received

WARNING: [gps] GPS out of sync, keeping previous time reference

WARNING: [gps] GPS out of sync, keeping previous time reference

##### 2018-09-29 00:14:39 GMT #####

### [UPSTREAM] ###

# RF packets received by concentrator: 1

# CRC_OK: 0.00%, CRC_FAIL: 100.00%, NO_CRC: 0.00>#/p###

# RF packets forwarded: 0 (0 bytes)

# PUSH_DATA datagrams sent: 0 (0 bytes)

# PUSH_DATA acknowledged: 0.00>#/p###

### [DOWNSTREAM] ###

# PULL_DATA sent: 3 (0.00% acknowledged)

# PULL_RESP(onse) datagrams received: 0 (0 bytes)

#...