class NanoGateway:
def __init__(self, id, frequency, datarate, ssid, password, server, port, ntp='pool.ntp.org', ntp_period=3600):
self.id = id
self.frequency = frequency
self.datarate = datarate
self.sf = self._dr_to_sf(datarate)
self.ssid = ssid
self.password = password
self.server = server
self.port = port
self.ntp = ntp
self.ntp_period = ntp_period
self.rxnb = 0
self.rxok = 0
self.rxfw = 0
self.dwnb = 0
self.txnb = 0
self.stat_alarm = None
self.pull_alarm = None
self.uplink_alarm = None
self.udp_lock = _thread.allocate_lock()
self.lora = None
self.lora_sock = None
def start(self):
# Change WiFi to STA mode and connect
self.wlan = WLAN(mode=WLAN.STA)
self._connect_to_wifi()
# Get a time Sync
self.rtc = machine.RTC()
self.rtc.ntp_sync(self.ntp, update_period=self.ntp_period)
# Get the server IP and create an UDP socket
self.server_ip = socket.getaddrinfo(self.server, self.port)[0][-1]
self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.sock.setblocking(False)
# Push the first time immediatelly
self._push_data(self._make_stat_packet())
# Create the alarms
self.stat_alarm = Timer.Alarm(handler=lambda t: self._push_data(self._make_stat_packet()), s=60, periodic=True)
self.pull_alarm = Timer.Alarm(handler=lambda u: self._pull_data(), s=25, periodic=True)
# Start the UDP receive thread
_thread.start_new_thread(self._udp_thread, ())
# Initialize LoRa in LORA mode
self.lora = LoRa(mode=LoRa.LORA, frequency=self.frequency, bandwidth=LoRa.BW_125KHZ, sf=self.sf,
preamble=8, coding_rate=LoRa.CODING_4_5, tx_iq=True)
# Create a raw LoRa socket
self.lora_sock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done = False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT | LoRa.TX_PACKET_EVENT), handler=self._lora_cb)
def stop(self):
# TODO: Check how to stop the NTP sync
# TODO: Create a cancel method for the alarm
# TODO: kill the UDP thread
self.sock.close()
def _connect_to_wifi(self):
self.wlan.connect(self.ssid, auth=(None, self.password))
while not self.wlan.isconnected():
time.sleep(0.5)
print("WiFi connected!")
def _dr_to_sf(self, dr):
sf = dr[2:4]
if sf[1] not in '0123456789':
sf = sf[:1]
return int(sf)
def _sf_to_dr(self, sf):
return self.datarate
def _make_stat_packet(self):
now = self.rtc.now()
STAT_PK["stat"]["time"] = "%d-%02d-%02d %02d:%02d:%02d GMT" % (now[0], now[1], now[2], now[3], now[4], now[5])
STAT_PK["stat"]["rxnb"] = self.rxnb
STAT_PK["stat"]["rxok"] = self.rxok
STAT_PK["stat"]["rxfw"] = self.rxfw
STAT_PK["stat"]["dwnb"] = self.dwnb
STAT_PK["stat"]["txnb"] = self.txnb
return json.dumps(STAT_PK)
def _make_node_packet(self, rx_data, rx_time, tmst, sf, rssi, snr):
RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4], rx_time[5], rx_time[6])
RX_PK["rxpk"][0]["tmst"] = tmst
RX_PK["rxpk"][0]["datr"] = self._sf_to_dr(sf)
RX_PK["rxpk"][0]["rssi"] = rssi
RX_PK["rxpk"][0]["lsnr"] = float(snr)
RX_PK["rxpk"][0]["data"] = binascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"] = len(rx_data)
return json.dumps(RX_PK)
def _push_data(self, data):
token = os.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PUSH_DATA]) + binascii.unhexlify(self.id) + data
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception:
print("PUSH exception")
def _pull_data(self):
token = os.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_DATA]) + binascii.unhexlify(self.id)
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception:
print("PULL exception")
def _ack_pull_rsp(self, token, error):
TX_ACK_PK["txpk_ack"]["error"] = error
resp = json.dumps(TX_ACK_PK)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_ACK]) + binascii.unhexlify(self.id) + resp
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception:
print("PULL RSP ACK exception")
def _lora_cb(self, lora):
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
self.rxnb += 1
self.rxok += 1
rx_data = self.lora_sock.recv(256)
stats = lora.stats()
#self._push_data(self._make_node_packet(rx_data, self.rtc.now(), stats.rx_timestamp, stats.sfrx, stats.rssi, stats.snr))
# Fix the "not joined yet" issue: https://forum.pycom.io/topic/1330/lopy-lorawan-gateway-with-an-st-lorawan-device/2
self._push_data(self._make_node_packet(rx_data, self.rtc.now(), time.ticks_us(), stats.sfrx, stats.rssi, stats.snr))
self.rxfw += 1
if events & LoRa.TX_PACKET_EVENT:
self.txnb += 1
lora.init(mode=LoRa.LORA, frequency=self.frequency, bandwidth=LoRa.BW_125KHZ,
sf=self.sf, preamble=8, coding_rate=LoRa.CODING_4_5, tx_iq=True)
def _send_down_link(self, data, tmst, datarate, frequency):
self.lora.init(mode=LoRa.LORA, frequency=frequency, bandwidth=LoRa.BW_125KHZ,
sf=self._dr_to_sf(datarate), preamble=8, coding_rate=LoRa.CODING_4_5,
tx_iq=True)
while time.ticks_us() < tmst:
pass
self.lora_sock.send(data)
def _udp_thread(self):
while True:
try:
data, src = self.sock.recvfrom(1024)
_token = data[1:3]
_type = data[3]
if _type == PUSH_ACK:
print("Push ack")
elif _type == PULL_ACK:
print("Pull ack")
elif _type == PULL_RESP:
self.dwnb += 1
ack_error = TX_ERR_NONE
tx_pk = json.loads(data[4:])
tmst = tx_pk["txpk"]["tmst"]
t_us = tmst - time.ticks_us() - 5000
if t_us < 0:
t_us += 0xFFFFFFFF
if t_us < 20000000:
self.uplink_alarm = Timer.Alarm(handler=lambda x: self._send_down_link(binascii.a2b_base64(tx_pk["txpk"]["data"]),
tx_pk["txpk"]["tmst"] - 10, tx_pk["txpk"]["datr"],
int(tx_pk["txpk"]["freq"] * 1000000)), us=t_us)
else:
ack_error = TX_ERR_TOO_LATE
print("Downlink timestamp error!, t_us:", t_us)
self._ack_pull_rsp(_token, ack_error)
print("Pull rsp")
except socket.timeout:
pass
except OSError as e:
if e.errno == errno.EAGAIN:
pass
else:
print("UDP recv OSError Exception")
except Exception:
print("UDP recv Exception")
# Wait before trying to receive again
time.sleep(0.025)
class NanoGateway:
"""
Nano gateway class, set up by default for use with TTN, but can be configured
for any other network supporting the Semtech Packet Forwarder.
Only required configuration is wifi_ssid and wifi_password which are used for
connecting to the Internet.
"""
def __init__(self,
id,
frequency,
datarate,
server,
port,
ntp_server='pool.ntp.org',
ntp_period=3600):
self.id = id
self.server = server
self.port = port
self.frequency = frequency
self.datarate = datarate
# self.ssid = ssid
# self.password = password
self.ntp_server = ntp_server
self.ntp_period = ntp_period
self.server_ip = None
self.rxnb = 0
self.rxok = 0
self.rxfw = 0
self.dwnb = 0
self.txnb = 0
self.sf = self._dr_to_sf(self.datarate)
self.bw = self._dr_to_bw(self.datarate)
self.stat_alarm = None
self.pull_alarm = None
self.uplink_alarm = None
self.lte = None
self.sock = None
self.udp_stop = False
self.udp_lock = _thread.allocate_lock()
self.lora = None
self.lora_sock = None
self.rtc = machine.RTC()
def start(self):
"""
Starts the LoRaWAN nano gateway.
"""
pycom.heartbeat(False)
self._log('Starting LoRaWAN nano gateway with id: {}', self.id)
# # setup WiFi as a station and connect
# self.wlan = WLAN(mode=WLAN.STA)
# self._connect_to_wifi()
# setup LTE CATM1 connection
self.lte = LTE(carrier="verizon")
self._connect_to_LTE()
# get a time sync
self._log('Syncing time with {} ...', self.ntp_server)
self.rtc.ntp_sync(self.ntp_server, update_period=self.ntp_period)
while not self.rtc.synced():
utime.sleep_ms(50)
self._log("RTC NTP sync complete")
# get the server IP and create an UDP socket
self.server_ip = usocket.getaddrinfo(self.server, self.port)[0][-1]
self._log('Opening UDP socket to {} ({}) port {}...', self.server,
self.server_ip[0], self.server_ip[1])
self.sock = usocket.socket(usocket.AF_INET, usocket.SOCK_DGRAM,
usocket.IPPROTO_UDP)
self.sock.setsockopt(usocket.SOL_SOCKET, usocket.SO_REUSEADDR, 1)
self.sock.setblocking(False)
# push the first time immediatelly
self._push_data(self._make_stat_packet())
# create the alarms
self.stat_alarm = Timer.Alarm(
handler=lambda t: self._push_data(self._make_stat_packet()),
s=60,
periodic=True)
self.pull_alarm = Timer.Alarm(handler=lambda u: self._pull_data(),
s=25,
periodic=True)
# start the UDP receive thread
self.udp_stop = False
_thread.start_new_thread(self._udp_thread, ())
# initialize the LoRa radio in LORA mode
self._log('Setting up the LoRa radio at {} Mhz using {}',
self._freq_to_float(self.frequency), self.datarate)
self.lora = LoRa(mode=LoRa.LORA,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True)
# create a raw LoRa socket
self.lora_sock = usocket.socket(usocket.AF_LORA, usocket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done = False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT
| LoRa.TX_PACKET_EVENT),
handler=self._lora_cb)
self._log('LoRaWAN nano gateway online')
def stop(self):
"""
Stops the LoRaWAN nano gateway.
"""
self._log('Stopping...')
# send the LoRa radio to sleep
self.lora.callback(trigger=None, handler=None)
self.lora.power_mode(LoRa.SLEEP)
# stop the NTP sync
self.rtc.ntp_sync(None)
# cancel all the alarms
self.stat_alarm.cancel()
self.pull_alarm.cancel()
# signal the UDP thread to stop
self.udp_stop = True
while self.udp_stop:
utime.sleep_ms(50)
# disable LTE
self.lte.disconnect()
self.lte.dettach()
def _connect_to_wifi(self):
self.wlan.connect(self.ssid, auth=(None, self.password))
while not self.wlan.isconnected():
utime.sleep_ms(50)
self._log('WiFi connected to: {}', self.ssid)
def _connect_to_LTE(self):
print("reset modem")
try:
self.lte.reset()
except:
print("Exception during reset")
print("delay 5 secs")
utime.sleep(5.0)
if self.lte.isattached():
try:
print("LTE was already attached, disconnecting...")
if self.lte.isconnected():
print("disconnect")
self.lte.disconnect()
except:
print("Exception during disconnect")
try:
if self.lte.isattached():
print("detach")
self.lte.dettach()
except:
print("Exception during dettach")
try:
print("resetting modem...")
self.lte.reset()
except:
print("Exception during reset")
print("delay 5 secs")
utime.sleep(5.0)
# enable network registration and location information, unsolicited result code
self.at('AT+CEREG=2')
# print("full functionality level")
self.at('AT+CFUN=1')
utime.sleep(1.0)
# using Hologram SIM
self.at('AT+CGDCONT=1,"IP","hologram"')
print("attempt to attach cell modem to base station...")
# lte.attach() # do not use attach with custom init for Hologram SIM
self.at("ATI")
utime.sleep(2.0)
i = 0
while self.lte.isattached() == False:
# get EPS Network Registration Status:
# +CEREG: <stat>[,[<tac>],[<ci>],[<AcT>]]
# <tac> values:
# 0 - not registered
# 1 - registered, home network
# 2 - not registered, but searching...
# 3 - registration denied
# 4 - unknown (out of E-UTRAN coverage)
# 5 - registered, roaming
r = self.at('AT+CEREG?')
try:
r0 = r[0] # +CREG: 2,<tac>
r0x = r0.split(',') # ['+CREG: 2',<tac>]
tac = int(r0x[1]) # 0..5
print("tac={}".format(tac))
except IndexError:
tac = 0
print("Index Error!!!")
# get signal strength
# +CSQ: <rssi>,<ber>
# <rssi>: 0..31, 99-unknown
r = self.at('AT+CSQ')
# extended error report
# r = at('AT+CEER')
if self.lte.isattached():
print("Modem attached (isattached() function worked)!!!")
break
if (tac == 1) or (tac == 5):
print("Modem attached!!!")
break
i = i + 5
print("not attached: {} secs".format(i))
if (tac != 0):
self.blink(BLUE, tac)
else:
self.blink(RED, 5)
utime.sleep(2)
self.at('AT+CEREG?')
print("connect: start a data session and obtain an IP address")
self.lte.connect(cid=3)
i = 0
while not self.lte.isconnected():
i = i + 1
print("not connected: {}".format(i))
self.blink(YELLOW, 1)
utime.sleep(1.0)
print("connected!!!")
pycom.rgbled(GREEN)
def _dr_to_sf(self, dr):
sf = dr[2:4]
if sf[1] not in '0123456789':
sf = sf[:1]
return int(sf)
def _dr_to_bw(self, dr):
bw = dr[-5:]
if bw == 'BW125':
return LoRa.BW_125KHZ
elif bw == 'BW250':
return LoRa.BW_250KHZ
else:
return LoRa.BW_500KHZ
def _sf_bw_to_dr(self, sf, bw):
dr = 'SF' + str(sf)
if bw == LoRa.BW_125KHZ:
return dr + 'BW125'
elif bw == LoRa.BW_250KHZ:
return dr + 'BW250'
else:
return dr + 'BW500'
def _lora_cb(self, lora):
"""
LoRa radio events callback handler.
"""
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
self.rxnb += 1
self.rxok += 1
rx_data = self.lora_sock.recv(256)
stats = lora.stats()
packet = self._make_node_packet(rx_data, self.rtc.now(),
stats.rx_timestamp, stats.sfrx,
self.bw, stats.rssi, stats.snr)
self._push_data(packet)
self._log('Received packet: {}', packet)
self.rxfw += 1
if events & LoRa.TX_PACKET_EVENT:
self.txnb += 1
lora.init(mode=LoRa.LORA,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True)
def _freq_to_float(self, frequency):
"""
MicroPython has some inprecision when doing large float division.
To counter this, this method first does integer division until we
reach the decimal breaking point. This doesn't completely elimate
the issue in all cases, but it does help for a number of commonly
used frequencies.
"""
divider = 6
while divider > 0 and frequency % 10 == 0:
frequency = frequency // 10
divider -= 1
if divider > 0:
frequency = frequency / (10**divider)
return frequency
def _make_stat_packet(self):
now = self.rtc.now()
STAT_PK["stat"]["time"] = "%d-%02d-%02d %02d:%02d:%02d GMT" % (
now[0], now[1], now[2], now[3], now[4], now[5])
STAT_PK["stat"]["rxnb"] = self.rxnb
STAT_PK["stat"]["rxok"] = self.rxok
STAT_PK["stat"]["rxfw"] = self.rxfw
STAT_PK["stat"]["dwnb"] = self.dwnb
STAT_PK["stat"]["txnb"] = self.txnb
return ujson.dumps(STAT_PK)
def _make_node_packet(self, rx_data, rx_time, tmst, sf, bw, rssi, snr):
RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (
rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4],
rx_time[5], rx_time[6])
RX_PK["rxpk"][0]["tmst"] = tmst
RX_PK["rxpk"][0]["freq"] = self._freq_to_float(self.frequency)
RX_PK["rxpk"][0]["datr"] = self._sf_bw_to_dr(sf, bw)
RX_PK["rxpk"][0]["rssi"] = rssi
RX_PK["rxpk"][0]["lsnr"] = snr
RX_PK["rxpk"][0]["data"] = ubinascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"] = len(rx_data)
return ujson.dumps(RX_PK)
def _push_data(self, data):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes(
[PUSH_DATA]) + ubinascii.unhexlify(self.id) + data
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to push uplink packet to server: {}', ex)
def _pull_data(self):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes(
[PULL_DATA]) + ubinascii.unhexlify(self.id)
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to pull downlink packets from server: {}',
ex)
def _ack_pull_rsp(self, token, error):
TX_ACK_PK["txpk_ack"]["error"] = error
resp = ujson.dumps(TX_ACK_PK)
packet = bytes([PROTOCOL_VERSION]) + token + bytes(
[PULL_ACK]) + ubinascii.unhexlify(self.id) + resp
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('PULL RSP ACK exception: {}', ex)
def _send_down_link(self, data, tmst, datarate, frequency):
"""
Transmits a downlink message over LoRa.
"""
self.lora.init(mode=LoRa.LORA,
frequency=frequency,
bandwidth=self._dr_to_bw(datarate),
sf=self._dr_to_sf(datarate),
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True)
while utime.ticks_cpu() < tmst:
pass
self.lora_sock.send(data)
self._log(
'Sent downlink packet scheduled on {:.3f}, at {:.3f} Mhz using {}: {}',
tmst / 1000000, self._freq_to_float(frequency), datarate, data)
def _udp_thread(self):
"""
UDP thread, reads data from the server and handles it.
"""
while not self.udp_stop:
try:
data, src = self.sock.recvfrom(1024)
_token = data[1:3]
_type = data[3]
if _type == PUSH_ACK:
self._log("Push ack")
elif _type == PULL_ACK:
self._log("Pull ack")
elif _type == PULL_RESP:
self.dwnb += 1
ack_error = TX_ERR_NONE
tx_pk = ujson.loads(data[4:])
tmst = tx_pk["txpk"]["tmst"]
t_us = tmst - utime.ticks_cpu() - 15000
if t_us < 0:
t_us += 0xFFFFFFFF
if t_us < 20000000:
self.uplink_alarm = Timer.Alarm(
handler=lambda x: self._send_down_link(
ubinascii.a2b_base64(tx_pk["txpk"]["data"]),
tx_pk["txpk"]["tmst"] - 50, tx_pk["txpk"][
"datr"],
int(tx_pk["txpk"]["freq"] * 1000) * 1000),
us=t_us)
else:
ack_error = TX_ERR_TOO_LATE
self._log('Downlink timestamp error!, t_us: {}', t_us)
self._ack_pull_rsp(_token, ack_error)
self._log("Pull rsp")
except usocket.timeout:
pass
except OSError as ex:
if ex.errno != errno.EAGAIN:
self._log('UDP recv OSError Exception: {}', ex)
except Exception as ex:
self._log('UDP recv Exception: {}', ex)
# wait before trying to receive again
utime.sleep_ms(UDP_THREAD_CYCLE_MS)
# we are to close the socket
self.sock.close()
self.udp_stop = False
self._log('UDP thread stopped')
def _log(self, message, *args):
"""
Outputs a log message to stdout.
"""
print('[{:>10.3f}] {}'.format(utime.ticks_ms() / 1000,
str(message).format(*args)))
def at(self, cmd):
print("modem command: {}".format(cmd))
r = self.lte.send_at_cmd(cmd).split('\r\n')
r = list(filter(None, r))
print("response={}".format(r))
return r
def blink(self, rgb, n):
for i in range(n):
pycom.rgbled(rgb)
utime.sleep(0.25)
pycom.rgbled(BLACK)
utime.sleep(0.1)
class NanoGateway:
"""
Nano gateway class, set up by default for use with TTN, but can be configured
for any other network supporting the Semtech Packet Forwarder.
Only required configuration is wifi_ssid and wifi_password which are used for
connecting to the Internet.
"""
def __init__(self, id, frequency, datarate, ssid, password, server, port, ntp_server='pool.ntp.org', ntp_period=3600):
self.id = id
self.server = server
self.port = port
self.frequency = frequency
self.datarate = datarate
self.ssid = ssid
self.password = password
self.ntp_server = ntp_server
self.ntp_period = ntp_period
self.server_ip = None
self.rxnb = 0
self.rxok = 0
self.rxfw = 0
self.dwnb = 0
self.txnb = 0
self.sf = self._dr_to_sf(self.datarate)
self.bw = self._dr_to_bw(self.datarate)
self.stat_alarm = None
self.pull_alarm = None
self.uplink_alarm = None
self.wlan = None
self.sock = None
self.udp_stop = False
self.udp_lock = _thread.allocate_lock()
self.lora = None
self.lora_sock = None
self.rtc = machine.RTC()
def start(self):
"""
Starts the LoRaWAN nano gateway.
"""
self._log('Starting LoRaWAN nano gateway with id: {}', self.id)
# setup WiFi as a station and connect
self.wlan = WLAN(mode=WLAN.STA)
self._connect_to_wifi()
# get a time sync
self._log('Syncing time with {} ...', self.ntp_server)
self.rtc.ntp_sync(self.ntp_server, update_period=self.ntp_period)
while not self.rtc.synced():
utime.sleep_ms(50)
self._log("RTC NTP sync complete")
# get the server IP and create an UDP socket
self.server_ip = usocket.getaddrinfo(self.server, self.port)[0][-1]
self._log('Opening UDP socket to {} ({}) port {}...', self.server, self.server_ip[0], self.server_ip[1])
self.sock = usocket.socket(usocket.AF_INET, usocket.SOCK_DGRAM, usocket.IPPROTO_UDP)
self.sock.setsockopt(usocket.SOL_SOCKET, usocket.SO_REUSEADDR, 1)
self.sock.setblocking(False)
# push the first time immediatelly
self._push_data(self._make_stat_packet())
# create the alarms
self.stat_alarm = Timer.Alarm(handler=lambda t: self._push_data(self._make_stat_packet()), s=60, periodic=True)
self.pull_alarm = Timer.Alarm(handler=lambda u: self._pull_data(), s=25, periodic=True)
# start the UDP receive thread
self.udp_stop = False
_thread.start_new_thread(self._udp_thread, ())
# initialize the LoRa radio in LORA mode
self._log('Setting up the LoRa radio at {:.1f} Mhz using {}', self._freq_to_float(self.frequency), self.datarate)
self.lora = LoRa(
mode=LoRa.LORA,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True
)
# create a raw LoRa socket
self.lora_sock = usocket.socket(usocket.AF_LORA, usocket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done = False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT | LoRa.TX_PACKET_EVENT), handler=self._lora_cb)
self._log('LoRaWAN nano gateway online')
def stop(self):
"""
Stops the LoRaWAN nano gateway.
"""
self._log('Stopping...')
# send the LoRa radio to sleep
self.lora.callback(trigger=None, handler=None)
self.lora.power_mode(LoRa.SLEEP)
# stop the NTP sync
self.rtc.ntp_sync(None)
# cancel all the alarms
self.stat_alarm.cancel()
self.pull_alarm.cancel()
# signal the UDP thread to stop
self.udp_stop = True
while self.udp_stop:
utime.sleep_ms(50)
# disable WLAN
self.wlan.disconnect()
self.wlan.deinit()
def _connect_to_wifi(self):
self.wlan.connect(self.ssid, auth=(None, self.password))
while not self.wlan.isconnected():
utime.sleep_ms(50)
self._log('WiFi connected to: {}', self.ssid)
def _dr_to_sf(self, dr):
sf = dr[2:4]
if sf[1] not in '0123456789':
sf = sf[:1]
return int(sf)
def _dr_to_bw(self, dr):
bw = dr[-5:]
if bw == 'BW125':
return LoRa.BW_125KHZ
elif bw == 'BW250':
return LoRa.BW_250KHZ
else:
return LoRa.BW_500KHZ
def _sf_bw_to_dr(self, sf, bw):
dr = 'SF' + str(sf)
if bw == LoRa.BW_125KHZ:
return dr + 'BW125'
elif bw == LoRa.BW_250KHZ:
return dr + 'BW250'
else:
return dr + 'BW500'
def _lora_cb(self, lora):
"""
LoRa radio events callback handler.
"""
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
self.rxnb += 1
self.rxok += 1
rx_data = self.lora_sock.recv(256)
stats = lora.stats()
packet = self._make_node_packet(rx_data, self.rtc.now(), stats.rx_timestamp, stats.sfrx, self.bw, stats.rssi, stats.snr)
self._push_data(packet)
self._log('Received packet: {}', packet)
self.rxfw += 1
if events & LoRa.TX_PACKET_EVENT:
self.txnb += 1
lora.init(
mode=LoRa.LORA,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True
)
def _freq_to_float(self, frequency):
"""
MicroPython has some inprecision when doing large float division.
To counter this, this method first does integer division until we
reach the decimal breaking point. This doesn't completely elimate
the issue in all cases, but it does help for a number of commonly
used frequencies.
"""
divider = 6
while divider > 0 and frequency % 10 == 0:
frequency = frequency // 10
divider -= 1
if divider > 0:
frequency = frequency / (10 ** divider)
return frequency
def _make_stat_packet(self):
now = self.rtc.now()
STAT_PK["stat"]["time"] = "%d-%02d-%02d %02d:%02d:%02d GMT" % (now[0], now[1], now[2], now[3], now[4], now[5])
STAT_PK["stat"]["rxnb"] = self.rxnb
STAT_PK["stat"]["rxok"] = self.rxok
STAT_PK["stat"]["rxfw"] = self.rxfw
STAT_PK["stat"]["dwnb"] = self.dwnb
STAT_PK["stat"]["txnb"] = self.txnb
return ujson.dumps(STAT_PK)
def _make_node_packet(self, rx_data, rx_time, tmst, sf, bw, rssi, snr):
RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4], rx_time[5], rx_time[6])
RX_PK["rxpk"][0]["tmst"] = tmst
RX_PK["rxpk"][0]["freq"] = self._freq_to_float(self.frequency)
RX_PK["rxpk"][0]["datr"] = self._sf_bw_to_dr(sf, bw)
RX_PK["rxpk"][0]["rssi"] = rssi
RX_PK["rxpk"][0]["lsnr"] = snr
RX_PK["rxpk"][0]["data"] = ubinascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"] = len(rx_data)
return ujson.dumps(RX_PK)
def _push_data(self, data):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PUSH_DATA]) + ubinascii.unhexlify(self.id) + data
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to push uplink packet to server: {}', ex)
def _pull_data(self):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_DATA]) + ubinascii.unhexlify(self.id)
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to pull downlink packets from server: {}', ex)
def _ack_pull_rsp(self, token, error):
TX_ACK_PK["txpk_ack"]["error"] = error
resp = ujson.dumps(TX_ACK_PK)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_ACK]) + ubinascii.unhexlify(self.id) + resp
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('PULL RSP ACK exception: {}', ex)
def _send_down_link(self, data, tmst, datarate, frequency):
"""
Transmits a downlink message over LoRa.
"""
self.lora.init(
mode=LoRa.LORA,
frequency=frequency,
bandwidth=self._dr_to_bw(datarate),
sf=self._dr_to_sf(datarate),
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True
)
while utime.ticks_us() < tmst:
pass
self.lora_sock.send(data)
self._log(
'Sent downlink packet scheduled on {:.3f}, at {:.1f} Mhz using {}: {}',
tmst / 1000000,
self._freq_to_float(frequency),
datarate,
data
)
def _udp_thread(self):
"""
UDP thread, reads data from the server and handles it.
"""
while not self.udp_stop:
try:
data, src = self.sock.recvfrom(1024)
_token = data[1:3]
_type = data[3]
if _type == PUSH_ACK:
self._log("Push ack")
elif _type == PULL_ACK:
self._log("Pull ack")
elif _type == PULL_RESP:
self.dwnb += 1
ack_error = TX_ERR_NONE
tx_pk = ujson.loads(data[4:])
tmst = tx_pk["txpk"]["tmst"]
t_us = tmst - utime.ticks_us() - 12500
if t_us < 0:
t_us += 0xFFFFFFFF
if t_us < 20000000:
self.uplink_alarm = Timer.Alarm(
handler=lambda x: self._send_down_link(
ubinascii.a2b_base64(tx_pk["txpk"]["data"]),
tx_pk["txpk"]["tmst"] - 50, tx_pk["txpk"]["datr"],
int(tx_pk["txpk"]["freq"] * 1000000)
),
us=t_us
)
else:
ack_error = TX_ERR_TOO_LATE
self._log('Downlink timestamp error!, t_us: {}', t_us)
self._ack_pull_rsp(_token, ack_error)
self._log("Pull rsp")
except usocket.timeout:
pass
except OSError as ex:
if ex.errno != errno.EAGAIN:
self._log('UDP recv OSError Exception: {}', ex)
except Exception as ex:
self._log('UDP recv Exception: {}', ex)
# wait before trying to receive again
utime.sleep_ms(UDP_THREAD_CYCLE_MS)
# we are to close the socket
self.sock.close()
self.udp_stop = False
self._log('UDP thread stopped')
def _log(self, message, *args):
"""
Outputs a log message to stdout.
"""
print('[{:>10.3f}] {}'.format(
utime.ticks_ms() / 1000,
str(message).format(*args)
))
class LoraSense:
"""
Class object that receives optional pin arguments for the SDA-pin (Serial Data), the SCL-pin (Serial Clock) and the
pin for the photometry module. The defaults are SDA = Pin3, SCL = Pin4, Phot = Pin20 on the Pycom Extension Board v3.1.
"""
def __init__(self, sda="P3", scl="P4", als="P20", frequency=1, mode=0, debug=0):
if not (mode == 0 or mode == 1):
self.__exitError("Please initialize this module in either mode 0 or mode 1.")
self.mode = mode
self.rtc = RTC()
self.debug = debug
self.wlan = WLAN(mode=WLAN.STA)
self.UDPactive = False
self.loraActive = False
if (mode == 0):
adc = ADC()
self.bme280 = bme280.BME280(i2c=I2C(pins=(sda, scl)))
self.l_pin = adc.channel(pin=als)
self.frequency = frequency
"""
This procedure sets up the LoRa-connection.
"""
def setupLoRa(self, mode=LoRa.LORA, region=LoRa.EU868, tx_power=14, sf=7):
self.lora = LoRa(mode=mode, region=region)
self.lora.init(mode=mode, tx_power=tx_power, sf=sf)
self.lorasocket = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
self.lorasocket.setblocking(False)
self.loraActive = True
def setupWLAN(self, ssid, pw, timeout=60):
self.wlan.connect(ssid=ssid, auth=(WLAN.WPA2, pw))
counter = 0
print("Connecting to WLAN", end = '')
while not self.wlan.isconnected():
counter = counter + 1
if (counter == timeout):
print("Unable to connect (timed out).")
return
time.sleep(1)
print(".", end = '')
if self.wlan.isconnected():
print(" Connected!")
counter = 0
self.rtc.ntp_sync("0.ch.pool.ntp.org")
print("Connecting to NTP server ", end = '')
while not self.rtc.synced():
counter = counter + 1
if (counter == timeout):
print("Unable to connect (timed out).")
return
print(".", end = '')
time.sleep(1)
print(" Completed!")
def setupUDP(self, IP, port):
self.__debug("DEBUG: STARTING UDP -> IP: {} Port: {}$".format(IP, port))
if not self.wlan.isconnected():
self.__exitError("Please establish a WLAN connection first.")
if (self.mode == 0):
print("UDP can only be set up in mode 1.")
elif (self.mode == 1):
self.UDPaddress = (IP, port)
print("Establishing a UDP connection.. to {}".format(self.UDPaddress[0]))
self.UDPsocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.UDPsocket.connect(self.UDPaddress)
self.UDPsocket.sendto("Establish".encode("utf-8"), self.UDPaddress)
self.UDPactive = True
else:
print("LoRa mode must be either 0 or 1.s")
def setSendFreq(self, sec):
self.frequency = sec
def startCommunication(self):
if self.mode == 0:
self.__commInMode0()
elif self.mode == 1:
self.__commInMode1()
def __createSocketList(self):
if (self.loraActive and self.UDPactive):
return [self.lorasocket, self.UDPsocket]
elif (self.loraActive and not self.UDPactive):
return [self.lorasocket]
elif (not self.loraActive and self.UDPactive):
return [self.UDPsocket]
else:
self.__exitError("Please establish a LoRa or a UDP connection before starting communication.")
def __commInMode0(self):
self.sockets = self.__createSocketList()
self.__debug("Communication in mode 0 initiated. Sockets = {}".format(self.sockets))
while True:
readIn, writeOut, excep = select.select(self.sockets, self.sockets, [])
for insocket in readIn:
if insocket == self.lorasocket:
info = insocket.recv(52)
print(info)
self.__processInfo(info)
elif insocket == self.UDPsocket:
info = insocket.recv(52)
print(info)
insocket.send(info)
for outsocket in writeOut:
if outsocket == self.lorasocket:
print(self.__getValues())
self.lorasocket.send(self.__getValues())
time.sleep(self.frequency)
def __commInMode1(self):
self.sockets = self.__createSocketList()
self.__debug("Communication in mode 1 initiated. Sockets = {}".format(self.sockets))
while True:
readIn, writeOut, excep = select.select(self.sockets, self.sockets, [])
for insocket in readIn:
if insocket == self.lorasocket:
info = insocket.recv(52)
insocket.send(info)
self.__sendUDP(info)
elif insocket == self.UDPsocket:
info = insocket.recv(52)
self.lorasocket.send(info)
def __getTimeStamp(self, offset_sec=0, offset_min=0, offset_hour=0, offset_day=0, offset_month=0, offset_year=0):
self.rtc.ntp_sync("0.ch.pool.ntp.org")
time = self.rtc.now()
seconds = self.__zfill(str(time[5] + offset_sec),2)
minutes = self.__zfill(str(time[4] + offset_min),2)
hour = self.__zfill(time[3] + offset_hour,2)
day = time[2] + offset_day
month = time[1] + offset_month
year = time[0] - 2000 + offset_year
return "{}/{}/{}|{}:{}:{}|".format(day, month, year, hour, minutes, seconds)
def __zfill(self, s, width):
return '{:0>{w}}'.format(s, w=width)
def __getValues(self):
t, p, h = self.bme280.values
li = self.l_pin()
msg = '{:.02f}|{:.02f}|{:.02f}|{:.02f}'.format(t, p, h, li / 4095 * 100)
if self.wlan.isconnected():
if (self.debug == 1):
print(self.__getTimeStamp(offset_hour=2) + msg)
return self.__getTimeStamp(offset_hour=2) + msg
else:
if (self.debug == 1):
print(msg)
return msg
def __sendLoRa(self):
self.__getTimeStamp(offset_hour=2)
self.lorasocket.send(self.__getValues())
def __sendInfo(self):
while True:
self.__sendLoRa()
time.sleep(self.frequency)
def __getInfo(self):
try:
while True:
info = self.lorasocket.recv(52)
if self.UDPactive:
self.__sendUDP(info)
if self.debug == 1: print(info)
time.sleep(1)
except UnicodeError:
pass
def __processInfo(self, info):
try:
info = info.decode("utf-8").split("|")
if (info[0] == "freq"):
self.frequency = int(info[1])
print("New frequency set: {}".format(int(info[1])))
except UnicodeError:
pass
def showIP(self):
if self.wlan.isconnected():
print("IP: {}".format(self.wlan.ifconfig()[0]))
else:
print("You need to establish an internet connection first.")
def __sendUDP(self, msg):
self.UDPsocket.sendto(msg, self.UDPaddress)
def __getUDP(self):
while True:
data, ip = self.UDPsocket.recvfrom(1024)
if data:
print("Data: " + data.decode())
def __exitError(self, str):
print('\033[91m' + "Error: " + str + '\x1b[0m')
sys.exit()
def __debug(self, str):
if self.debug == 1:
print('\033[93m' + "Debug: " + str + '\x1b[0m')
class NanoGateway:
"""
Nano gateway class, set up by default for use with TTN, but can be configured
for any other network supporting the Semtech Packet Forwarder.
Only required configuration is wifi_ssid and wifi_password which are used for
connecting to the Internet.
"""
def __init__(self,
id,
frequency,
datarate,
ssid,
password,
server,
port,
ntp_server='pool.ntp.org',
ntp_period=3600):
self.id = id
self.server = server
self.port = port
self.frequency = frequency
self.datarate = datarate
self.ssid = ssid
self.password = password
self.ntp_server = ntp_server
self.ntp_period = ntp_period
self.server_ip = None
self.rxnb = 0
self.rxok = 0
self.rxfw = 0
self.dwnb = 0
self.txnb = 0
self.sf = self._dr_to_sf(self.datarate)
self.bw = self._dr_to_bw(self.datarate)
self.stat_alarm = None
self.pull_alarm = None
self.uplink_alarm = None
self.wlan = None
self.sock = None
self.udp_stop = False
self.udp_lock = _thread.allocate_lock()
self.lora = None
self.lora_sock = None
self.rtc = machine.RTC()
def start(self):
"""
Starts the LoRaWAN nano gateway.
"""
self._log('Starting LoRaWAN nano gateway with id: {}', self.id)
# setup WiFi as a station and connect
self.wlan = WLAN(mode=WLAN.STA)
self._connect_to_wifi()
# get a time sync
self._log('Syncing time with {} ...', self.ntp_server)
self.rtc.ntp_sync(self.ntp_server, update_period=self.ntp_period)
while not self.rtc.synced():
utime.sleep_ms(50)
self._log("RTC NTP sync complete")
# get the server IP and create an UDP socket
self.server_ip = usocket.getaddrinfo(self.server, self.port)[0][-1]
self._log('Opening UDP socket to {} ({}) port {}...', self.server,
self.server_ip[0], self.server_ip[1])
self.sock = usocket.socket(usocket.AF_INET, usocket.SOCK_DGRAM,
usocket.IPPROTO_UDP)
self.sock.setsockopt(usocket.SOL_SOCKET, usocket.SO_REUSEADDR, 1)
self.sock.setblocking(False)
# push the first time immediatelly
self._push_data(self._make_stat_packet())
# create the alarms
self.stat_alarm = Timer.Alarm(
handler=lambda t: self._push_data(self._make_stat_packet()),
s=60,
periodic=True)
self.pull_alarm = Timer.Alarm(handler=lambda u: self._pull_data(),
s=25,
periodic=True)
# start the UDP receive thread
self.udp_stop = False
_thread.start_new_thread(self._udp_thread, ())
# initialize the LoRa radio in LORA mode
self._log('Setting up the LoRa radio at {} Mhz using {}',
self._freq_to_float(self.frequency), self.datarate)
self.lora = LoRa(mode=LoRa.LORA,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True)
# create a raw LoRa socket
self.lora_sock = usocket.socket(usocket.AF_LORA, usocket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done = False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT
| LoRa.TX_PACKET_EVENT),
handler=self._lora_cb)
self._log('LoRaWAN nano gateway online')
def stop(self):
"""
Stops the LoRaWAN nano gateway.
"""
self._log('Stopping...')
# send the LoRa radio to sleep
self.lora.callback(trigger=None, handler=None)
self.lora.power_mode(LoRa.SLEEP)
# stop the NTP sync
self.rtc.ntp_sync(None)
# cancel all the alarms
self.stat_alarm.cancel()
self.pull_alarm.cancel()
# signal the UDP thread to stop
self.udp_stop = True
while self.udp_stop:
utime.sleep_ms(50)
# disable WLAN
self.wlan.disconnect()
self.wlan.deinit()
def _connect_to_wifi(self):
self.wlan.connect(self.ssid, auth=(None, self.password))
while not self.wlan.isconnected():
utime.sleep_ms(50)
self._log('WiFi connected to: {}', self.ssid)
def _dr_to_sf(self, dr):
sf = dr[2:4]
if sf[1] not in '0123456789':
sf = sf[:1]
return int(sf)
def _dr_to_bw(self, dr):
bw = dr[-5:]
if bw == 'BW125':
return LoRa.BW_125KHZ
elif bw == 'BW250':
return LoRa.BW_250KHZ
else:
return LoRa.BW_500KHZ
def _sf_bw_to_dr(self, sf, bw):
dr = 'SF' + str(sf)
if bw == LoRa.BW_125KHZ:
return dr + 'BW125'
elif bw == LoRa.BW_250KHZ:
return dr + 'BW250'
else:
return dr + 'BW500'
def _lora_cb(self, lora):
"""
LoRa radio events callback handler.
"""
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
self.rxnb += 1
self.rxok += 1
rx_data = self.lora_sock.recv(256)
stats = lora.stats()
packet = self._make_node_packet(rx_data, self.rtc.now(),
stats.rx_timestamp, stats.sfrx,
self.bw, stats.rssi, stats.snr)
self._push_data(packet)
self._log('Received packet: {}', packet)
self.rxfw += 1
if events & LoRa.TX_PACKET_EVENT:
self.txnb += 1
lora.init(mode=LoRa.LORA,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True)
def _freq_to_float(self, frequency):
"""
MicroPython has some inprecision when doing large float division.
To counter this, this method first does integer division until we
reach the decimal breaking point. This doesn't completely elimate
the issue in all cases, but it does help for a number of commonly
used frequencies.
"""
divider = 6
while divider > 0 and frequency % 10 == 0:
frequency = frequency // 10
divider -= 1
if divider > 0:
frequency = frequency / (10**divider)
return frequency
def _make_stat_packet(self):
now = self.rtc.now()
STAT_PK["stat"]["time"] = "%d-%02d-%02d %02d:%02d:%02d GMT" % (
now[0], now[1], now[2], now[3], now[4], now[5])
STAT_PK["stat"]["rxnb"] = self.rxnb
STAT_PK["stat"]["rxok"] = self.rxok
STAT_PK["stat"]["rxfw"] = self.rxfw
STAT_PK["stat"]["dwnb"] = self.dwnb
STAT_PK["stat"]["txnb"] = self.txnb
return ujson.dumps(STAT_PK)
def _make_node_packet(self, rx_data, rx_time, tmst, sf, bw, rssi, snr):
RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (
rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4],
rx_time[5], rx_time[6])
RX_PK["rxpk"][0]["tmst"] = tmst
RX_PK["rxpk"][0]["freq"] = self._freq_to_float(self.frequency)
RX_PK["rxpk"][0]["datr"] = self._sf_bw_to_dr(sf, bw)
RX_PK["rxpk"][0]["rssi"] = rssi
RX_PK["rxpk"][0]["lsnr"] = snr
RX_PK["rxpk"][0]["data"] = ubinascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"] = len(rx_data)
return ujson.dumps(RX_PK)
def _push_data(self, data):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes(
[PUSH_DATA]) + ubinascii.unhexlify(self.id) + data
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to push uplink packet to server: {}', ex)
def _pull_data(self):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes(
[PULL_DATA]) + ubinascii.unhexlify(self.id)
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to pull downlink packets from server: {}',
ex)
def _ack_pull_rsp(self, token, error):
TX_ACK_PK["txpk_ack"]["error"] = error
resp = ujson.dumps(TX_ACK_PK)
packet = bytes([PROTOCOL_VERSION]) + token + bytes(
[PULL_ACK]) + ubinascii.unhexlify(self.id) + resp
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('PULL RSP ACK exception: {}', ex)
def _send_down_link(self, data, tmst, datarate, frequency):
"""
Transmits a downlink message over LoRa.
"""
self.lora.init(mode=LoRa.LORA,
frequency=frequency,
bandwidth=self._dr_to_bw(datarate),
sf=self._dr_to_sf(datarate),
preamble=8,
coding_rate=LoRa.CODING_4_5,
tx_iq=True)
while utime.ticks_cpu() < tmst:
pass
self.lora_sock.send(data)
self._log(
'Sent downlink packet scheduled on {:.3f}, at {:.3f} Mhz using {}: {}',
tmst / 1000000, self._freq_to_float(frequency), datarate, data)
def _udp_thread(self):
"""
UDP thread, reads data from the server and handles it.
"""
while not self.udp_stop:
try:
data, src = self.sock.recvfrom(1024)
_token = data[1:3]
_type = data[3]
if _type == PUSH_ACK:
self._log("Push ack")
elif _type == PULL_ACK:
self._log("Pull ack")
elif _type == PULL_RESP:
self.dwnb += 1
ack_error = TX_ERR_NONE
tx_pk = ujson.loads(data[4:])
tmst = tx_pk["txpk"]["tmst"]
t_us = tmst - utime.ticks_cpu() - 15000
if t_us < 0:
t_us += 0xFFFFFFFF
if t_us < 20000000:
self.uplink_alarm = Timer.Alarm(
handler=lambda x: self._send_down_link(
ubinascii.a2b_base64(tx_pk["txpk"]["data"]),
tx_pk["txpk"]["tmst"] - 50, tx_pk["txpk"][
"datr"],
int(tx_pk["txpk"]["freq"] * 1000) * 1000),
us=t_us)
else:
ack_error = TX_ERR_TOO_LATE
self._log('Downlink timestamp error!, t_us: {}', t_us)
self._ack_pull_rsp(_token, ack_error)
self._log("Pull rsp")
except usocket.timeout:
pass
except OSError as ex:
if ex.errno != errno.EAGAIN:
self._log('UDP recv OSError Exception: {}', ex)
except Exception as ex:
self._log('UDP recv Exception: {}', ex)
# wait before trying to receive again
utime.sleep_ms(UDP_THREAD_CYCLE_MS)
# we are to close the socket
self.sock.close()
self.udp_stop = False
self._log('UDP thread stopped')
def _log(self, message, *args):
"""
Outputs a log message to stdout.
"""
print('[{:>10.3f}] {}'.format(utime.ticks_ms() / 1000,
str(message).format(*args)))
class NanoGateway:
def __init__(self, id, frequency, datarate, ssid, password, server, port, ntp='pool.ntp.org', ntp_period=3600):
self.id = id
self.frequency = frequency
self.datarate = datarate
self.sf = self._dr_to_sf(datarate)
self.ssid = ssid
self.password = password
self.server = server
self.port = port
self.ntp = ntp
self.ntp_period = ntp_period
self.rxnb = 0
self.rxok = 0
self.rxfw = 0
self.dwnb = 0
self.txnb = 0
self.stat_alarm = None
self.pull_alarm = None
self.uplink_alarm = None
self.udp_lock = _thread.allocate_lock()
self.lora = None
self.lora_sock = None
def start(self):
# Change WiFi to STA mode and connect
self.wlan = WLAN(mode=WLAN.STA)
self._connect_to_wifi()
# Get a time Sync
self.rtc = machine.RTC()
self.rtc.ntp_sync(self.ntp, update_period=self.ntp_period)
# Get the server IP and create an UDP socket
self.server_ip = socket.getaddrinfo(self.server, self.port)[0][-1]
self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.sock.setblocking(False)
# Push the first time immediatelly
self._push_data(self._make_stat_packet())
# Create the alarms
self.stat_alarm = Timer.Alarm(handler=lambda t: self._push_data(self._make_stat_packet()), s=60, periodic=True)
self.pull_alarm = Timer.Alarm(handler=lambda u: self._pull_data(), s=25, periodic=True)
# Start the UDP receive thread
_thread.start_new_thread(self._udp_thread, ())
# Initialize LoRa in LORA mode
self.lora = LoRa(mode=LoRa.LORA, frequency=self.frequency, bandwidth=LoRa.BW_125KHZ, sf=self.sf,
preamble=8, coding_rate=LoRa.CODING_4_5, tx_iq=True)
# Create a raw LoRa socket
self.lora_sock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done = False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT | LoRa.TX_PACKET_EVENT), handler=self._lora_cb)
def stop(self):
# TODO: Check how to stop the NTP sync
# TODO: Create a cancel method for the alarm
# TODO: kill the UDP thread
self.sock.close()
def _connect_to_wifi(self):
self.wlan.connect(self.ssid, auth=(None, self.password))
while not self.wlan.isconnected():
time.sleep(0.5)
print("WiFi connected!")
def _dr_to_sf(self, dr):
sf = dr[2:4]
if sf[1] not in '0123456789':
sf = sf[:1]
return int(sf)
def _sf_to_dr(self, sf):
return self.datarate
def _make_stat_packet(self):
now = self.rtc.now()
STAT_PK["stat"]["time"] = "%d-%02d-%02d %02d:%02d:%02d GMT" % (now[0], now[1], now[2], now[3], now[4], now[5])
STAT_PK["stat"]["rxnb"] = self.rxnb
STAT_PK["stat"]["rxok"] = self.rxok
STAT_PK["stat"]["rxfw"] = self.rxfw
STAT_PK["stat"]["dwnb"] = self.dwnb
STAT_PK["stat"]["txnb"] = self.txnb
return json.dumps(STAT_PK)
def _make_node_packet(self, rx_data, rx_time, tmst, sf, rssi, snr):
RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4], rx_time[5], rx_time[6])
RX_PK["rxpk"][0]["tmst"] = tmst
RX_PK["rxpk"][0]["datr"] = self._sf_to_dr(sf)
RX_PK["rxpk"][0]["rssi"] = rssi
RX_PK["rxpk"][0]["lsnr"] = float(snr)
RX_PK["rxpk"][0]["data"] = binascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"] = len(rx_data)
return json.dumps(RX_PK)
def _push_data(self, data):
token = os.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PUSH_DATA]) + binascii.unhexlify(self.id) + data
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception:
print("PUSH exception")
def _pull_data(self):
token = os.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_DATA]) + binascii.unhexlify(self.id)
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception:
print("PULL exception")
def _ack_pull_rsp(self, token, error):
TX_ACK_PK["txpk_ack"]["error"] = error
resp = json.dumps(TX_ACK_PK)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_ACK]) + binascii.unhexlify(self.id) + resp
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception:
print("PULL RSP ACK exception")
def _lora_cb(self, lora):
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
self.rxnb += 1
self.rxok += 1
rx_data = self.lora_sock.recv(256)
stats = lora.stats()
self._push_data(self._make_node_packet(rx_data, self.rtc.now(), stats.rx_timestamp, stats.sfrx, stats.rssi, stats.snr))
self.rxfw += 1
if events & LoRa.TX_PACKET_EVENT:
self.txnb += 1
lora.init(mode=LoRa.LORA, frequency=self.frequency, bandwidth=LoRa.BW_125KHZ,
sf=self.sf, preamble=8, coding_rate=LoRa.CODING_4_5, tx_iq=True)
def _send_down_link(self, data, tmst, datarate, frequency):
self.lora.init(mode=LoRa.LORA, frequency=frequency, bandwidth=LoRa.BW_125KHZ,
sf=self._dr_to_sf(datarate), preamble=8, coding_rate=LoRa.CODING_4_5,
tx_iq=True)
while time.ticks_us() < tmst:
pass
self.lora_sock.send(data)
def _udp_thread(self):
while True:
try:
data, src = self.sock.recvfrom(1024)
_token = data[1:3]
_type = data[3]
if _type == PUSH_ACK:
print("Push ack")
elif _type == PULL_ACK:
print("Pull ack")
elif _type == PULL_RESP:
self.dwnb += 1
ack_error = TX_ERR_NONE
tx_pk = json.loads(data[4:])
tmst = tx_pk["txpk"]["tmst"]
t_us = tmst - time.ticks_us() - 5000
if t_us < 0:
t_us += 0xFFFFFFFF
if t_us < 20000000:
self.uplink_alarm = Timer.Alarm(handler=lambda x: self._send_down_link(binascii.a2b_base64(tx_pk["txpk"]["data"]),
tx_pk["txpk"]["tmst"] - 10, tx_pk["txpk"]["datr"],
int(tx_pk["txpk"]["freq"] * 1000000)), us=t_us)
else:
ack_error = TX_ERR_TOO_LATE
print("Downlink timestamp error!, t_us:", t_us)
self._ack_pull_rsp(_token, ack_error)
print("Pull rsp")
except socket.timeout:
pass
except OSError as e:
if e.errno == errno.EAGAIN:
pass
else:
print("UDP recv OSError Exception")
except Exception:
print("UDP recv Exception")
# Wait before trying to receive again
time.sleep(0.025)
class NanoGateway:
"""
Nano gateway class, set up by default for use with TTN, but can be configured
for any other network supporting the Semtech Packet Forwarder.
Only required configuration is wifi_ssid and wifi_password which are used for
connecting to the Internet.
"""
def __init__(self, id, frequency, datarate, ssid, password, server, port, ntp_server='pool.ntp.org', ntp_period=3600):
self.id = id
self.server = server
self.port = port
self.frequency = frequency
self.datarate = datarate
self.ssid = ssid
self.password = password
self.ntp_server = ntp_server
self.ntp_period = ntp_period
self.server_ip = None
self.rxnb = 0
self.rxok = 0
self.rxfw = 0
self.dwnb = 0
self.txnb = 0
self.sf = self._dr_to_sf(self.datarate)
self.bw = self._dr_to_bw(self.datarate)
self.region = LoRa.AU915
self.stat_alarm = None
self.pull_alarm = None
self.uplink_alarm = None
self.wlan = None
self.sock = None
self.udp_stop = False
self.udp_lock = _thread.allocate_lock()
self.lora = None
self.lora_sock = None
self.rtc = machine.RTC()
def start(self):
"""
Starts the LoRaWAN nano gateway.
"""
self._log('Starting LoRaWAN nano gateway with id: {}', self.id)
# setup WiFi as a station and connect
self.wlan = WLAN(mode=WLAN.STA)
self._connect_to_wifi()
# get a time sync
self._log('Syncing time with {} ...', self.ntp_server)
self.rtc.ntp_sync(self.ntp_server, update_period=self.ntp_period)
while not self.rtc.synced():
utime.sleep_ms(50)
self._log("RTC NTP sync complete")
# get the server IP and create an UDP socket
self.server_ip = usocket.getaddrinfo(self.server, self.port)[0][-1]
self._log('Opening UDP socket to {} ({}) port {}...', self.server, self.server_ip[0], self.server_ip[1])
self.sock = usocket.socket(usocket.AF_INET, usocket.SOCK_DGRAM, usocket.IPPROTO_UDP)
self.sock.setsockopt(usocket.SOL_SOCKET, usocket.SO_REUSEADDR, 1)
self.sock.setblocking(False)
# push the first time immediatelly
self._push_data(self._make_stat_packet())
# create the alarms
self.stat_alarm = Timer.Alarm(handler=lambda t: self._push_data(self._make_stat_packet()), s=60, periodic=True)
self.pull_alarm = Timer.Alarm(handler=lambda u: self._pull_data(), s=25, periodic=True)
# start the UDP receive thread
self.udp_stop = False
_thread.start_new_thread(self._udp_thread, ())
# initialize the LoRa radio in LORA mode
self._log('Setting up the LoRa radio at {} Mhz using {}', self._freq_to_float(self.frequency), self.datarate)
self.lora = LoRa(
mode=LoRa.LORA,
region=self.region,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
power_mode=LoRa.ALWAYS_ON,
#tx_iq=True
)
# create a raw LoRa socket
self.lora_sock = usocket.socket(usocket.AF_LORA, usocket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done = False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT | LoRa.TX_PACKET_EVENT), handler=self._lora_cb)
if uos.uname()[0] == "LoPy":
self.window_compensation = -1000
else:
self.window_compensation = -6000
self.downlink_count = 0
self._log('LoRaWAN nano gateway online')
def stop(self):
"""
Stops the LoRaWAN nano gateway.
"""
self._log('Stopping...')
# send the LoRa radio to sleep
self.lora.callback(trigger=None, handler=None)
self.lora.power_mode(LoRa.SLEEP)
# stop the NTP sync
self.rtc.ntp_sync(None)
# cancel all the alarms
self.stat_alarm.cancel()
self.pull_alarm.cancel()
# signal the UDP thread to stop
self.udp_stop = True
while self.udp_stop:
utime.sleep_ms(50)
# disable WLAN
self.wlan.disconnect()
self.wlan.deinit()
def _connect_to_wifi(self):
self.wlan.connect(self.ssid, auth=(None, self.password))
while not self.wlan.isconnected():
utime.sleep_ms(50)
self._log('WiFi connected to: {}', self.ssid)
def _dr_to_sf(self, dr):
sf = dr[2:4]
if sf[1] not in '0123456789':
sf = sf[:1]
return int(sf)
def _dr_to_bw(self, dr):
bw = dr[-5:]
if bw == 'BW125':
return LoRa.BW_125KHZ
elif bw == 'BW250':
return LoRa.BW_250KHZ
else:
return LoRa.BW_500KHZ
def _sf_bw_to_dr(self, sf, bw):
dr = 'SF' + str(sf)
if bw == LoRa.BW_125KHZ:
return dr + 'BW125'
elif bw == LoRa.BW_250KHZ:
return dr + 'BW250'
else:
return dr + 'BW500'
def _lora_cb(self, lora):
"""
LoRa radio events callback handler.
"""
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
self.rxnb += 1
self.rxok += 1
rx_data = self.lora_sock.recv(256)
stats = lora.stats()
if DEBUG:
self._log("stats "+ujson.dumps(stats))
self._log('rx_timestamp diff: {}', utime.ticks_diff(stats.rx_timestamp,utime.ticks_cpu()))
packet = self._make_node_packet(rx_data, self.rtc.now(), stats.rx_timestamp, stats.sfrx, self.bw, stats.rssi, stats.snr)
packet = self.frequency_rounding_fix(packet, self.frequency)
self._log('Received and uploading packet: {}', packet)
self._push_data(packet)
self._log('after _push_data')
self.rxfw += 1
if events & LoRa.TX_PACKET_EVENT:
self.txnb += 1
lora.init(
mode=LoRa.LORA,
region=self.region,
frequency=self.frequency,
bandwidth=self.bw,
sf=self.sf,
preamble=8,
coding_rate=LoRa.CODING_4_5,
power_mode=LoRa.ALWAYS_ON,
#tx_iq=True
)
def _freq_to_float(self, frequency):
"""
MicroPython has some inprecision when doing large float division.
To counter this, this method first does integer division until we
reach the decimal breaking point. This doesn't completely elimate
the issue in all cases, but it does help for a number of commonly
used frequencies.
"""
divider = 6
while divider > 0 and frequency % 10 == 0:
frequency = frequency // 10
divider -= 1
if divider > 0:
frequency = frequency / (10 ** divider)
return frequency
def frequency_rounding_fix(self, packet, frequency):
freq = str(frequency)[0:3] + '.' + str(frequency)[3]
start = packet.find("freq\":")
end = packet.find(",", start)
packet = packet[:start + 7] + freq + packet[end:]
return packet
def _make_stat_packet(self):
now = self.rtc.now()
STAT_PK["stat"]["time"] = "%d-%02d-%02d %02d:%02d:%02d GMT" % (now[0], now[1], now[2], now[3], now[4], now[5])
STAT_PK["stat"]["rxnb"] = self.rxnb
STAT_PK["stat"]["rxok"] = self.rxok
STAT_PK["stat"]["rxfw"] = self.rxfw
STAT_PK["stat"]["dwnb"] = self.dwnb
STAT_PK["stat"]["txnb"] = self.txnb
return ujson.dumps(STAT_PK)
def _make_node_packet(self, rx_data, rx_time, tmst, sf, bw, rssi, snr):
RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4], rx_time[5], rx_time[6])
RX_PK["rxpk"][0]["tmst"] = tmst
RX_PK["rxpk"][0]["freq"] = self._freq_to_float(self.frequency)
RX_PK["rxpk"][0]["datr"] = self._sf_bw_to_dr(sf, bw)
RX_PK["rxpk"][0]["rssi"] = rssi
RX_PK["rxpk"][0]["lsnr"] = snr
RX_PK["rxpk"][0]["data"] = ubinascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"] = len(rx_data)
return ujson.dumps(RX_PK)
def _push_data(self, data):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PUSH_DATA]) + ubinascii.unhexlify(self.id) + data
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to push uplink packet to server: {}', ex)
def _pull_data(self):
token = uos.urandom(2)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_DATA]) + ubinascii.unhexlify(self.id)
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('Failed to pull downlink packets from server: {}', ex)
def _ack_pull_rsp(self, token, error):
TX_ACK_PK["txpk_ack"]["error"] = error
resp = ujson.dumps(TX_ACK_PK)
packet = bytes([PROTOCOL_VERSION]) + token + bytes([PULL_ACK]) + ubinascii.unhexlify(self.id) + resp
with self.udp_lock:
try:
self.sock.sendto(packet, self.server_ip)
except Exception as ex:
self._log('PULL RSP ACK exception: {}', ex)
def _send_down_link(self, data, tmst, datarate, frequency):
"""
Transmits a downlink message over LoRa.
"""
self.lora.init(
mode=LoRa.LORA,
region=self.region,
frequency=frequency,
bandwidth=self._dr_to_bw(datarate), # LoRa.BW_125KHZ
sf=self._dr_to_sf(datarate),
preamble=8,
coding_rate=LoRa.CODING_4_5,
power_mode=LoRa.ALWAYS_ON,
#tx_iq=True
)
if WINDOW_COMPENSATION=='cycle':
self.window_compensation = -((self.downlink_count % 25) * 1000)
else:
self.window_compensation = WINDOW_COMPENSATION
t_adj = utime.ticks_add(tmst, self.window_compensation)
self.lora_sock.settimeout(1)
t_cpu = utime.ticks_cpu()
self._log("BEFORE spin wait at {} late {}",t_cpu,t_cpu-tmst)
while utime.ticks_diff(t_adj, utime.ticks_cpu()) > 0:
pass
t_cpu = utime.ticks_cpu()
self._log("BEFORE lora_sock.send at {} late {} window_compensation {}",t_cpu,t_cpu-tmst,self.window_compensation)
self.lora_sock.send(data)
self._log("AFTER lora_sock.send late {}",utime.ticks_cpu()-tmst)
self.lora_sock.setblocking(False)
self._log(
'Sent downlink packet scheduled on {}, at {:,d} Hz using {}: {}',
tmst,
frequency,
datarate,
data
)
self.downlink_count += 1
def _send_down_link_class_c(self, data, datarate, frequency):
self.lora.init(
mode=LoRa.LORA,
frequency=frequency,
bandwidth=self._dr_to_bw(datarate),
sf=self._dr_to_sf(datarate),
preamble=8,
coding_rate=LoRa.CODING_4_5,
region=self.region,
power_mode=LoRa.ALWAYS_ON,
#tx_iq=True,
device_class=LoRa.CLASS_C
)
self.lora_sock.send(data)
self._log(
'Sent downlink packet scheduled on {}, at {:.3f} Mhz using {}: {}',
utime.ticks_cpu(),
self._freq_to_float(frequency),
datarate,
data
)
def _udp_thread(self):
"""
UDP thread, reads data from the server and handles it.
"""
loops = 0
while not self.udp_stop:
if loops % 20 == 19:
b4 = utime.ticks_cpu()
gc.collect()
self._log("gc.collect for {} us",utime.ticks_diff(utime.ticks_cpu(),b4))
b4 = utime.ticks_cpu()
utime.sleep_ms(UDP_THREAD_CYCLE_MS)
t_diff = utime.ticks_diff(utime.ticks_cpu(),b4)
if t_diff > (UDP_THREAD_CYCLE_MS*1000*1.5):
self._log("overslept! for {} us",t_diff)
try:
b4 = utime.ticks_cpu()
data, src = self.sock.recvfrom(1024)
self._log("sock.recvfrom for {} us",utime.ticks_diff(utime.ticks_cpu(),b4))
_token = data[1:3]
_type = data[3]
if _type == PUSH_ACK:
self._log("Push ack")
elif _type == PULL_ACK:
self._log("Pull ack")
elif _type == PULL_RESP:
self._log("Pull resp")
self.dwnb += 1
ack_error = TX_ERR_NONE
tx_pk = ujson.loads(data[4:])
if DEBUG:
self._log("tx data "+ujson.dumps(tx_pk))
payload = ubinascii.a2b_base64(tx_pk["txpk"]["data"])
# depending on the board, pull the downlink message 1 or 6 ms upfronnt
# tmst = utime.ticks_add(tx_pk["txpk"]["tmst"], self.window_compensation)
# t_us = utime.ticks_diff(utime.ticks_cpu(), utime.ticks_add(tmst, -15000))
tmst = tx_pk["txpk"]["tmst"]
t_req = utime.ticks_add(tmst, -RX_DELAY_TIMER_EARLY)
t_cpu = utime.ticks_cpu()
self._log("t_cpu {}",t_cpu)
t_us = utime.ticks_diff(t_req, t_cpu)
self._log("t_us {}",t_us)
if 1000 < t_us < 10000000:
self._log("Delaying for {} at {}, so should fire at t_req {}, compensated early_by {}",t_us,t_cpu,t_req,RX_DELAY_TIMER_EARLY)
def handler(x):
t_cpu = utime.ticks_cpu()
self._log("_send_down_link alarm fired at {} late {}us",t_cpu,t_cpu-t_req)
self._send_down_link(
payload,
tmst, tx_pk["txpk"]["datr"],
int(tx_pk["txpk"]["freq"] * 1000 + 0.0005) * 1000
)
self.uplink_alarm = Timer.Alarm(handler=handler, us=t_us)
else:
ack_error = TX_ERR_TOO_LATE
self._log('Downlink timestamp error!, t_us: {}', t_us)
self._ack_pull_rsp(_token, ack_error)
self._log("Pull rsp")
except usocket.timeout:
pass
except OSError as ex:
if ex.args[0] != errno.EAGAIN:
self._log('UDP recv OSError Exception: {}', ex)
except Exception as ex:
self._log('UDP recv Exception: {}', ex)
# we are to close the socket
self.sock.close()
self.udp_stop = False
self._log('UDP thread stopped')
def _log(self, message, *args):
"""
Outputs a log message to stdout.
"""
if len(args)==0:
print('[{}] '.format(utime.ticks_cpu()) + str(message))
else:
print('[{}] {}'.format(
utime.ticks_cpu(),
str(message).format(*args)
))
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setsockopt(socket.SOL_LORA, socket.SO_DR, 5)
s.setblocking(False)
s.bind(2)
# try all the datarates from 0 to 6 and toggle confirmed and non confirmed messages
for i in range(7):
print(s.send("Sending pk #%d" % i))
time.sleep(0.5)
# the packet should not have been received yet as it's non-blocking
print(lora.events() == LoRa.TX_PACKET_EVENT)
print(lora.events() == 0)
time.sleep(2)
lora.init(mode=LoRa.LORAWAN, public=True, adr=False)
try:
s.send('123')
except Exception as e:
if e.errno == errno.ENETDOWN:
print('Exception')
otaa_join(lora)
def lora_cb_handler(lora):
global s
print(type(lora))
try:
events = lora.events()
if events & LoRa.TX_PACKET_EVENT:
]
rand_index = random_integer(0, 3)
return list_of_coding_rate_values[rand_index]
# LoRa setup
lora = LoRa(mode=LoRa.LORA, rx_iq=True)
#lora.init(mode=LoRa.LORA, tx_power=14, bandwidth=LoRa.BW_125KHZ, sf=12, coding_rate=LoRa.CODING_4_5)
lora_sock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
lora_sock.setblocking(False)
while True:
lora.init(mode=LoRa.LORA,
tx_power=14,
bandwidth=LoRa.BW_125KHZ,
sf=12,
coding_rate=LoRa.CODING_4_7)
tx_p = randomize_tx_power()
bw = randomize_bandwith()
s_f = randomize_sf()
c_r = randomize_coding_rate()
# time.sleep(1)
"""
Broadcast new parameters to nodes
"""
for i in range(0, 5):
lora_params = str(5-i) + "|" + str(tx_p) + "|" + str(bw) + "|" + \
str(s_f) + "|" + str(c_r)
# print("NEW PARAMETERS: ", lora_params)
def receive_data():
global index
global guard
global slot
global packet_size
lora = LoRa(mode=LoRa.LORA,
rx_iq=True,
frequency=freqs[my_sf - 5],
region=LoRa.EU868,
power_mode=LoRa.ALWAYS_ON,
bandwidth=my_bw,
sf=my_sf)
lora_sock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
lora_sock.setblocking(False)
guard = 1000 * guard
(overall_received, overall_sent) = (0, 0)
airt = int(airtime_calc(my_sf, 1, packet_size + 2, my_bw_plain) * 1000)
duty_cycle_limit_slots = math.ceil(100 * airt / (airt + 2 * guard))
print("duty cycle slots:", duty_cycle_limit_slots)
print("packet airtime (ms):", airt / 1000)
print("guard time (ms):", guard / 1000)
chrono = Timer.Chrono()
chrono.start()
i = 1
while (True):
print(i, "----------------------------------------------------")
print("Net size is:", index + 1)
chrono.reset()
round_start = chrono.read_us()
received = 0
acks = []
if (int(index) > duty_cycle_limit_slots):
round_length = math.ceil(int(index) * (airt + 2 * guard))
else:
round_length = math.ceil(duty_cycle_limit_slots *
(airt + 2 * guard))
lora.init(mode=LoRa.LORA,
rx_iq=True,
region=LoRa.EU868,
frequency=freqs[my_sf - 5],
power_mode=LoRa.ALWAYS_ON,
bandwidth=my_bw,
sf=my_sf)
rec_start = chrono.read_us()
pycom.rgbled(green)
while ((chrono.read_us() - round_start) <
round_length - 66000): # the following line may take up to 66ms
recv_pkg = lora_sock.recv(256)
if (len(recv_pkg) > 2):
recv_pkg_len = recv_pkg[1]
recv_pkg_id = recv_pkg[0]
if (int(recv_pkg_id) <= 35) and (int(recv_pkg_len)
== int(packet_size)):
dev_id, leng, msg = struct.unpack(
_LORA_RCV_PKG_FORMAT % recv_pkg_len, recv_pkg)
if (len(msg) == packet_size): # format check
received += 1
# print('Received from: %d' % dev_id)
# print(lora.stats())
acks.append(str(int(dev_id)))
pycom.rgbled(off)
print(received, "packets received")
rec_lasted = chrono.read_us() - rec_start
if (rec_lasted < round_length):
print("I'll sleep a bit to align with the round length")
time.sleep_us(int(round_length - rec_lasted))
print("Receiving lasted (ms):", (chrono.read_us() - rec_start) / 1000)
print("...should last (ms):", round_length / 1000)
proc_t = chrono.read_us()
ack_msg = ""
for n in range(int(index) + 1):
if n in slot:
id = str(slot[n])
if id in acks:
ack_msg = ack_msg + "1"
else:
ack_msg = ack_msg + "0"
if (ack_msg != ""):
ack_msg = str(hex(int(ack_msg, 2)))[2:]
print("proc time (ms):", (chrono.read_us() - proc_t) / 1000)
proc_t = chrono.read_us() - proc_t
if (i % sync_rate == 0): # SACK
sync_start = chrono.read_us()
pycom.rgbled(white)
time.sleep_us(int(guard * 3 /
2)) # let's make it long so all the nodes are up
lora.init(mode=LoRa.LORA,
tx_iq=True,
frequency=freqs[my_sf - 5],
region=LoRa.EU868,
power_mode=LoRa.ALWAYS_ON,
bandwidth=my_bw,
sf=my_sf,
tx_power=14)
data = str(index + 1) + ":" + str(int(
proc_t / 1000)) + ":" + ack_msg
pkg = struct.pack(_LORA_PKG_FORMAT % len(data), MY_ID, len(data),
data)
pycom.rgbled(red)
lora_sock.send(pkg)
print("Sent sync: " + data)
pycom.rgbled(off)
time.sleep_ms(13) # node time after sack
print("sync lasted (ms):", (chrono.read_us() - sync_start) / 1000)
print("round lasted (ms):", (chrono.read_us() - round_start) / 1000)
i += 1
