lorawan_gateway.py

""""
Raspberry Pi Single Channel Gateway

Learn Guide: https://learn.adafruit.com/raspberry-pi-single-channel-lorawan-gateway
Author: Brent Rubell for Adafruit Industries
Modified for Console output only - 2019 Cees Meijer
"""
# Import Python System Libraries
import sys
import json
import time
import subprocess
import uuid
# Import Adafruit Blinka Libraries
import busio
from digitalio import DigitalInOut, Direction, Pull
import board

# Create the I2C interface.
i2c = busio.I2C(board.SCL, board.SDA)

# Gateway id calculation (based off MAC address)
mac_addr = hex(uuid.getnode()).replace('0x', '')
print('Gateway ID: {0}:{1}:{2}:ff:ff:{3}:{4}:{5}'.format(mac_addr[0:2],mac_addr[2:4],
                                                         mac_addr[4:6],mac_addr[6:8],
                                                         mac_addr[8:10], mac_addr[10:12]))

# Parse `global_conf.json`
with open('global_conf.json', 'r') as config:
    gateway_config = json.load(config)
# parse `SX127x_conf`
SX127x_conf = gateway_config['SX127x_conf']
gateway_freq = SX127x_conf['freq']/1000000
gateway_sf = SX127x_conf['spread_factor']
# parse `gateway_conf`
gateway_conf = gateway_config['gateway_conf']
gateway_name = gateway_conf['name']
# parse 'gateway_conf[servers]'
server_list = gateway_conf['servers']
ttn_server = server_list[0]
ttn_server_addr = ttn_server['address']

def stats():
    """Prints information about the Pi
    to a display
    """
    print('Pi Stats')
    # Shell scripts for system monitoring from here :
    # https://unix.stackexchange.com/questions/119126/command-to-display-memory-usage-disk-usage-and-cpu-load
    cmd = "hostname -I | cut -d\' \' -f1"
    IP = subprocess.check_output(cmd, shell=True).decode("utf-8")
    cmd = "top -bn1 | grep load | awk '{printf \"CPU Load: %.2f\", $(NF-2)}'"
    CPU = subprocess.check_output(cmd, shell=True).decode("utf-8")
    cmd = "free -m | awk 'NR==2{printf \"Mem: %s/%s MB  %.2f%%\", $3,$2,$3*100/$2 }'"
    MemUsage = subprocess.check_output(cmd, shell=True).decode("utf-8")
    # write text to display
    print("IP: "+str(IP)+"CPU:"+str(CPU)+"MEM:"+str(MemUsage))

def gateway():
    """Runs the single channel packet forwarder,
    sends output to a display.
    """
    print('MODE: Pi Gateway')
    print('starting gateway...')
    try:
        proc = subprocess.Popen("./single_chan_pkt_fwd",
                                bufsize=-1, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    except FileNotFoundError:
        print("To run the single packet forwarder, you'll need to run `sudo make all` first.")
        return
    while True:
        new_line = proc.stdout.readline().decode('utf-8')
        print(new_line)
        # grab new data on gateway status update
        if new_line == "gateway status update\n":
            gtwy_timestamp = proc.stdout.readline().decode('utf-8')
            print('time:', gtwy_timestamp)
            gtwy_status = proc.stdout.readline().decode('utf-8')
            print(gtwy_status)
            sys.stdout.write(u"\u001b[1000D") # Move left
            sys.stdout.write(u"\u001b[8A") # Move up
        elif new_line == "incoming packet...\n":
            print('incoming pkt...                         ')
            # read incoming packet info
            pkt_json = proc.stdout.readline().decode('utf-8')
            print(pkt_json)
            # parse packet
            pkt_data = json.loads(pkt_json)
            rxpk_data = pkt_data['rxpk']
            pkt_data = rxpk_data.pop(0)
            # display packet info
            pkt_freq = pkt_data['freq']
            pkt_size = pkt_data['size']
            pkt_rssi = pkt_data['rssi']
            pkt_tmst = pkt_data['tmst']
            print('* PKT RX on {0}MHz            '.format(pkt_freq))
            print('RSSI: {0}dBm, Size: {1} bytes '.format(pkt_rssi, pkt_size))
            print('timestamp: {0}                '.format(pkt_tmst))
            print();print();

def gateway_info():
    """Displays information about the LoRaWAN gateway.
    """
    print('MODE: Gateway Info')
    print('Server: ', ttn_server_addr[0:9])
    print('Freq: ', gateway_freq)
    print('SF: ', gateway_sf)
    print('Gateway Name:', gateway_name)


while True:
    print('LoRaWAN Gateway EUI:')
    print('{0}:{1}:{2}:ff:ff:{3}:{4}:{5}'.format(mac_addr[0:2], mac_addr[2:4],
                                        mac_addr[4:6],mac_addr[6:8],mac_addr[8:10],
                                         mac_addr[10:12]))
    stats()
    gateway_info()
    gateway()
    sys.stdout.write(u"\u001b[1000D") # Move left
    sys.stdout.write(u"\u001b[10A") # Move up

    time.sleep(1)