TTN can' show device data of LoPy

[Yunwei]

Hi,
I'm using two LoPy - one as LoRaWAN nano gateway, another as node device - to test the commnicatoin with TTN.
I'm using US915 frequency and ABP method.
Right now I can see the uplink data in gateway data traffic, and also the device status shows it's connected. But there is no data in application data page.
The status of TTN page shows below:

1. Gateway traffic
   

2. Device overview
   

3. Application data:
   

My code is below:

1. config.py

""" LoPy LoRaWAN Nano Gateway configuration options """

import machine
import ubinascii

WIFI_MAC = ubinascii.hexlify(machine.unique_id()).upper()
# Set  the Gateway ID to be the first 3 bytes of MAC address + 'FFFE' + last 3 bytes of MAC address
GATEWAY_ID = WIFI_MAC[:6] + "FFFE" + WIFI_MAC[6:12]

SERVER = 'router.us.thethings.network'
PORT = 1700

NTP = "pool.ntp.org"
NTP_PERIOD_S = 3600

WIFI_SSID = ''
WIFI_PASS = ''

# for EU868
#LORA_FREQUENCY = 868100000
#LORA_GW_DR = "SF7BW125" # DR_5
#LORA_NODE_DR = 5

# for US915
LORA_FREQUENCY = 903900000
LORA_GW_DR = "SF7BW125" # DR_3
#LORA_NODE_DR = 4

2. main.py

#####ABP example#####
from network import LoRa
import socket
import binascii
import struct
import time
import config

# initialize LoRa in LORAWAN mode.
# Please pick the region that matches where you are using the device:
# Asia = LoRa.AS923
# Australia = LoRa.AU915
# Europe = LoRa.EU868
# United States = LoRa.US915
lora = LoRa(mode=LoRa.LORAWAN, region=LoRa.US915)

# create an ABP authentication params
dev_addr = struct.unpack(">l", binascii.unhexlify(''))[0]
nwk_swkey = binascii.unhexlify('')
app_swkey = binascii.unhexlify('')

# remove all the channels
for channel in range(0, 72):
    lora.remove_channel(channel)

# set all channels to the same frequency (must be before sending the OTAA join request)
for channel in range(0, 72):
    lora.add_channel(channel, frequency=config.LORA_FREQUENCY, dr_min=0, dr_max=3)

# join a network using ABP (Activation By Personalization)
lora.join(activation=LoRa.ABP, auth=(dev_addr, nwk_swkey, app_swkey))

# create a LoRa socket
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)

# set the LoRaWAN data rate
s.setsockopt(socket.SOL_LORA, socket.SO_DR, 3)# last parameter is 3 

# make the socket non-blocking
s.setblocking(False)

for i in range (200):
    pkt = b'PKT #' + bytes([i])
    print('Sending:', pkt)
    s.send(pkt)
    time.sleep(4)
    rx, port = s.recvfrom(256)
    if rx:
        print('Received: {}, on port: {}'.format(rx, port))
    time.sleep(6)

I have deleted the data as device address, Network session key,etc.

Moreover, the OTAA can't work for me, always shows "Not joined yet" when using the sample code from pycom github...

The firmware version is :
sysname='LoPy', nodename='LoPy', release='1.17.5.b6', version='v1.8.6-849-56d00234 on 2018-05-18', machine='LoPy with ESP32', lorawan='1.0.2'

Hope you guys could help me!