Hi @gonzalocasas, I did the recompilation, the output of the packet forwarder is a lot of SPI: burst read succes actions. I flashed your code on the UNO after changing the device address. If I run the poly packet forwarder i get:

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 1
INFO: Configuring TX LUT with 16 indexes
INFO: radio 0 enabled (type SX1257), center frequency 867500000, RSSI offset -166.000000, tx enabled 1
INFO: radio 1 enabled (type SX1257), center frequency 868500000, RSSI offset -166.000000, tx enabled 0
INFO: Lora multi-SF channel 0> radio 1, IF -400000 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 1> radio 1, IF -200000 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 2> radio 1, IF 0 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 3> radio 0, IF -400000 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 4> radio 0, IF -200000 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 5> radio 0, IF 0 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 6> radio 0, IF 200000 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora multi-SF channel 7> radio 0, IF 400000 Hz, 125 kHz bw, SF 7 to 12
INFO: Lora std channel> radio 1, IF -200000 Hz, 250000 Hz bw, SF 7
INFO: FSK channel> radio 1, IF 300000 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 AA555A0000000000
INFO: Found 2 servers in array.
INFO: Server 0 configured to "127.0.0.1", with port up "1680" and port down "1681"
INFO: Server 1 configured to "iot.semtech.com", with port up "1680" and port down "1680"
INFO: Found 5 system calls in array.
INFO: System command 0: "df -m"
INFO: System command 1: "free -h"
INFO: System command 2: "uptime"
INFO: System command 3: "who -a"
INFO: System command 4: "uname -a"
INFO: monitor hostname or IP address is configured to "127.0.0.1"
INFO: monitor port is configured to "2008"
INFO: ghost hostname or IP address is configured to "127.0.0.1"
INFO: ghost port is configured to "1918"
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: SSH path is configured to "/usr/bin/ssh"
INFO: SSH port is configured to 22
INFO: HTTP port is configured to 80
INFO: NGROK path is configured to "/usr/bin/ngrok"
INFO: Reference latitude is configured to 10.000000 deg
INFO: Reference longitude is configured to 20.000000 deg
INFO: Reference altitude is configured to -1 meters
INFO: GPS is enabled
INFO: Using fake GPS coordinates instead of real.
INFO: Upstream data is enabled
INFO: Downstream data is enabled
INFO: Ghoststream data is disabled
INFO: Radiostream data is enabled
INFO: Statusstream data is enabled
INFO: Beacon is disabled
INFO: Monitor is disabled
INFO: Platform configured to "Lorank"
INFO: Contact email configured to "operator@gateway.tst"
INFO: Description configured to "Update me"
INFO: found local configuration file local_conf.json, parsing it
INFO: redefined parameters will overwrite global parameters
INFO: local_conf.json does not contain a JSON object named SX1301_conf
INFO: local_conf.json does contain a JSON object named gateway_conf, parsing gateway parameters
INFO: gateway MAC address is configured to FFFEB827EBDB5D47
INFO: Found 1 servers in array.
INFO: Server 0 configured to "croft.thethings.girovito.nl", with port up "1700" and port down "1701"
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: Reference latitude is configured to 0.000000 deg
INFO: Reference longitude is configured to 0.000000 deg
INFO: GPS is enabled
INFO: Upstream data is enabled
INFO: Downstream data is enabled
INFO: Ghoststream data is disabled
INFO: Radiostream data is enabled
INFO: Statusstream data is enabled
INFO: Beacon is disabled
INFO: Monitor is disabled
INFO: Contact email configured to "sven@tweetonig.nl"
INFO: Description configured to "tweetonig-ic880a"
INFO: Successfully contacted server croft.thethings.girovito.nl
INFO: [main] Starting the concentrator
INFO: [main] concentrator started, radio packets can now be received.
INFO: [down] Thread activated for all server croft.thethings.girovito.nl
INFO: [up] Thread activated for all servers.

2015-12-01 10:51:31 GMT

[UPSTREAM]

RF packets received by concentrator: 0

CRC_OK: 0.00%, CRC_FAIL: 0.00%, NO_CRC: 0.00%

RF packets forwarded: 0 (0 bytes)

PUSH_DATA datagrams sent: 0 (0 bytes)

PUSH_DATA acknowledged: 0.00%

[DOWNSTREAM]

PULL_DATA sent: 3 (0.00% acknowledged)

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

RF packets sent to concentrator: 0 (0 bytes)

TX errors: 0

[GPS]

Invalid gps time reference (age: 1448967091 sec)

Manual GPS coordinates: latitude 0.00000, longitude 0.00000, altitude -1 m

END

INFO: [up] PUSH_ACK for server croft.thethings.girovito.nl received in 61 ms