class LoRa
This class provides a LoRaWAN 1.0.2 compliant driver for the LoRa network processor in the LoPy and FiPy. Below is an example demonstrating LoRaWAN Activation by Personalisation usage:
from network import LoRa
import socket
import ubinascii
import struct
# Initialise 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.EU868)
# create an ABP authentication params
dev_addr = struct.unpack(">l", binascii.unhexlify('00000005'))[0]
nwk_swkey = ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
app_swkey = ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
# join a network using ABP (Activation By Personalisation)
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, 5)
# make the socket non-blocking
s.setblocking(False)
# send some data
s.send(bytes([0x01, 0x02, 0x03]))
# get any data received...
data = s.recv(64)
print(data)
Please ensure that there is an antenna connected to your device before sending/receiving LoRa messages as improper use (e.g. without an antenna), may damage the device.
Additional Examples
For various other complete LoRa examples, check here for additional examples.
Constructors
class network.LoRa(id=0, ...)
Create and configure a LoRa object. See init for params of configuration.
lora = LoRa(mode=LoRa.LORAWAN, region=LoRa.EU868)
Methods
lora.init(mode, * ,region=LoRa.EU868, frequency=868000000, tx_power=14, bandwidth=LoRa.BW_125KHZ, sf=7, preamble=8, coding_rate=LoRa.CODING_4_5, power_mode=LoRa.ALWAYS_ON, tx_iq=False, rx_iq=False, adr=False, public=True, tx_retries=1, device_class=LoRa.CLASS_A)
This method is used to set the LoRa subsystem configuration and to specific raw LoRa or LoRaWAN.
The arguments are:
mode
can be eitherLoRa.LORA orLoRa.LORAWAN .region
can take the following values:LoRa.AS923 ,LoRa.AU915 ,LoRa.EU868 orLoRa.US915 . If not provided this will default toLoRaEU868
. If they are not specified, this will also set appropriate defaults forfrequency
andtx_power
.frequency
accepts values between 863000000 and 870000000 in the 868 band, or between 902000000 and 928000000 in the 915 band.tx_power
is the transmit power in dBm. It accepts between 2 and 14 for the 868 band, and between 5 and 20 in the 915 band.bandwidth
is the channel bandwidth in KHz. In the 868 band the accepted values areLoRa.BW_125KHZ andLoRa.BW_250KHZ . In the 915 band the accepted values areLoRa.BW_125KHZ andLoRa.BW_500KHZ .sf
sets the desired spreading factor. Accepts values between 7 and 12.preamble
configures the number of pre-amble symbols. The default value is 8.coding_rate
can take the following values:LoRa.CODING_4_5 ,LoRa.CODING_4_6 ,LoRa.CODING_4_7 orLoRa.CODING_4_8 .power_mode
can be eitherLoRa.ALWAYS_ON ,LoRa.TX_ONLY orLoRa.SLEEP . InALWAYS_ON mode, the radio is always listening for incoming - packets whenever a transmission is not taking place. InTX_ONLY the radio goes to sleep as soon as the transmission completes. InSLEEP mode the radio is sent to sleep permanently and won’t accept any commands until the power mode is changed.tx_iq
enables TX IQ inversion.rx_iq
enables RX IQ inversion.adr
enables Adaptive Data Rate.public
selects between the public and private sync word.tx_retries
sets the number of TX retries inLoRa.LORAWAN mode.device_class
sets the LoRaWAN device class. Can be eitherLoRa.CLASS_A orLoRa.CLASS_C .
In adr
, public
, tx_retries
and device_class
are used. All the other params will be ignored as they are handled by the LoRaWAN stack directly. On the other hand, in adr
, tx_retries
and device_class
are ignored since they are only relevant to the LoRaWAN stack.
For example, you can do:
# initialize in raw LoRa mode
lora.init(mode=LoRa.LORA, tx_power=14, sf=12)
or:
# initialize in LoRaWAN mode
lora.init(mode=LoRa.LORAWAN)
lora.join(activation, auth, * ,timeout=None, dr=None)
Join a LoRaWAN network. Internally the stack will automatically retry every 15 seconds until a Join Accept message is received.
The parameters are:
activation
: can be eitherLoRa.OTAA orLoRa.ABP .auth
: is a tuple with the authentication data.timeout
: is the maximum time in milliseconds to wait for the Join Accept message to be received. If no timeout (or zero) is given, the call returns immediately and the status of the join request can be checked withlora.has_joined()
.dr
: is an optional value to specify the initial data rate for the Join Request. Possible values are 0 to 5 for EU868, or 0 to 4 for US915.
In the case of (dev_eui, app_eui, app_key)
where dev_eui
is optional. If it is
not provided the LoRa MAC will be used. Therefore, you can do OTAA in 2 different ways:
lora.join(activation=LoRa.OTAA, auth=(app_eui, app_key), timeout=0) # the device MAC address is used as DEV_EUI
or
lora.join(activation=LoRa.OTAA, auth=(dev_eui, app_eui, app_key), timeout=0) # a custom DEV_EUI is specified
Example:
from network import LoRa
import socket
import time
import ubinascii
# Initialise 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.EU868)
# create an OTAA authentication parameters
app_eui = ubinascii.unhexlify('ADA4DAE3AC12676B')
app_key = ubinascii.unhexlify('11B0282A189B75B0B4D2D8C7FA38548B')
# join a network using OTAA (Over the Air Activation)
lora.join(activation=LoRa.OTAA, auth=(app_eui, app_key), timeout=0)
# wait until the module has joined the network
while not lora.has_joined():
time.sleep(2.5)
print('Not yet joined...')
In the case of (dev_addr, nwk_swkey, app_swkey)
. Example:
from network import LoRa
import socket
import ubinascii
import struct
# Initialise 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.EU868)
# create an ABP authentication params
dev_addr = struct.unpack(">l", ubinascii.unhexlify('00000005'))[0]
nwk_swkey = ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
app_swkey = ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
# join a network using ABP (Activation By Personalisation)
lora.join(activation=LoRa.ABP, auth=(dev_addr, nwk_swkey, app_swkey))
lora.bandwidth([bandwidth])
Get or set the bandwidth in raw LoRa mode (
# get raw LoRa Bandwidth
lora.bandwidth()
# set raw LoRa Bandwidth
lora.bandwidth(LoRa.BW_125KHZ)
lora.frequency([frequency])
Get or set the frequency in raw LoRa mode (
# get raw LoRa Frequency
lora.frequency()
# set raw LoRa Frequency
lora.frequency(868000000)
lora.coding_rate([coding_rate])
Get or set the coding rate in raw LoRa mode (
# get raw LoRa Coding Rate
lora.coding_rate()
# set raw LoRa Coding Rate
lora.coding_rate(LoRa.CODING_4_5)
lora.preamble([preamble])
Get or set the number of preamble symbols in raw LoRa mode (
# get raw LoRa preamble symbols
lora.preamble()
# set raw LoRa preamble symbols
lora.preamble(LoRa.CODING_4_5)
lora.sf([sf])
Get or set the spreading factor value in raw LoRa mode (
# get raw LoRa spread factor value
lora.sf()
# set raw LoRa spread factor value
lora.sf(7)
lora.power_mode([power_mode])
Get or set the power mode in raw LoRa mode (
lora.stats()
Return a named tuple with useful information from the last received LoRa or LoRaWAN packet. The named tuple has the following form:
(rx_timestamp, rssi, snr, sftx, sfrx, tx_trials, tx_power, tx_time_on_air, tx_counter, tx_frequency)
Example:
lora.stats()
Where:
rx_timestamp
is an internal timestamp of the last received packet with microseconds precision.rssi
holds the received signal strength in dBm.snr
contains the signal to noise ratio id dB (as a single precision float).sfrx
tells the data rate (in the case of LORAWAN mode) or the spreading factor (in the case of LORA mode) of the last packet received.sftx
tells the data rate (in the case of LORAWAN mode) or the spreading factor (in the case of LORA mode) of the last packet transmitted.tx_trials
is the number of tx attempts of the last transmitted packet (only relevant for LORAWAN confirmed packets).tx_power
is the power of the last transmission (in dBm).tx_time_on_air
is the time on air of the last transmitted packet (in ms).tx_counter
is the number of packets transmitted.tx_frequency
is the frequency used for the last transmission.
lora.has_joined()
Returns True
if a LoRaWAN network has been joined. False
otherwise.:
lora.add_channel(index, * , frequency, dr_min, dr_max)
Add a LoRaWAN channel on the specified index
. If there’s already a channel with that index it will be replaced with the new one.
The arguments are:
index
: Index of the channel to add. Accepts values between 0 and 15 for EU and between 0 and 71 for US.frequency
: Centre frequency in Hz of the channel.dr_min
: Minimum data rate of the channel (0-7).dr_max
: Maximum data rate of the channel (0-7).
Examples:
lora.add_channel(index=0, frequency=868000000, dr_min=5, dr_max=6)
lora.remove_channel(index)
Removes the channel from the specified index
. On the 868MHz band the channels 0 to 2 cannot be removed, they can only be replaced by other channels using the lora.add_channel method. A way to remove all channels except for one is to add the same channel, 3 times on indexes 0, 1 and 2. An example can be seen below:
lora.remove_channel()
On the 915MHz band there are no restrictions around this.
lora.mac()
Returns a byte object with the 8-Byte MAC address of the LoRa radio.
lora.callback(trigger, handler=None, arg=None)
Specify a callback handler for the LoRa radio. The trigger
types are
The ack
is received. If the ack
is not received tx_retries
configured have been performed.
An example of how this callback functions can be seen the in method
lora.ischannel_free(rssi_threshold)
This method is used to check for radio activity on the current LoRa channel, and if the rssi
of the measured activity is lower than the rssi_threshold
given, the return value will be True
, otherwise False
. Example:
lora.ischannel_free(-100)
lora.set_battery_level(level)
Set the battery level value that will be sent when the LoRaWAN MAC command that retrieves the battery level is received. This command is sent by the network and handled automatically by the LoRaWAN stack. The values should be according to the LoRaWAN specification:
0
means that the end-device is connected to an external power source.1..254
specifies the battery level, 1 being at minimum and 254 being at maximum.255
means that the end-device was not able to measure the battery level.
lora.set_battery_level(127) # 50% battery
lora.events()
This method returns a value with bits sets (if any) indicating the events that have triggered the callback. Please note that by calling this function the internal events registry is cleared automatically, therefore calling it immediately for a second time will most likely return a value of 0.
Example:
def lora_cb(lora):
events = lora.events()
if events & LoRa.RX_PACKET_EVENT:
print('Lora packet received')
if events & LoRa.TX_PACKET_EVENT:
print('Lora packet sent')
lora.callback(trigger=(LoRa.RX_PACKET_EVENT | LoRa.TX_PACKET_EVENT), handler=lora_cb)
lora.nvram_save()
Save the LoRaWAN state (joined status, network keys, packet counters, etc) in non-volatile memory in order to be able to restore the state when coming out of deepsleep or a power cycle.
lora.nvram_save()
lora.nvram_restore()
Restore the LoRaWAN state (joined status, network keys, packet counters, etc)
from non-volatile memory. State must have been previously stored with a call to
nvram_save
before entering deepsleep. This is useful to be able to send a
LoRaWAN message immediately after coming out of deepsleep without having to join
the network again. This can only be used if the current region matches the one
saved.
lora.nvram_restore()
lora.nvram_erase()
Remove the LoRaWAN state (joined status, network keys, packet counters, etc) from non-volatile memory.
lora.nvram_erase()
lora.nvram_erase()
Remove the LoRaWAN state (joined status, network keys, packet counters, etc) from non-volatile memory.
lora.nvram_erase()
lora.mesh()
Enable the Mesh network. Only after Mesh enabling the socket
can be used.
lora.mesh()
lora.cli()
Send OpenThread CLI commands, the list is here.
The output is multiline string, having as line-endings the \r\n
.
>>> print(lora.cli("ipaddr"))
fdde:ad00:beef:0:0:ff:fe00:fc00
fdde:ad00:beef:0:0:ff:fe00:e800
fdde:ad00:beef:0:e1f0:783c:1e8f:c763
fe80:0:0:0:2c97:cb65:3219:c86
Constants
Working with LoRa and LoRaWAN Sockets
LoRa sockets are created in the following way:
import socket
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
And they must be created after initialising the LoRa network card.
LoRa-Mesh socket is created, if the Mesh was enabled before (
The LoRa-Mesh socket supports only the following socket methods:
LoRa sockets support the following standard methods from the socket module:
socket.close()
Usage:
s.close()
socket.bind(port_number)
Usage:
s.bind(1)
The
socket.send(bytes)
Usage:
s.send(bytes([1, 2, 3]))
or:
s.send('Hello')
socket.sendto(bytes,(ip, port))
This is supported only by the LoRa Mesh socket.
Usage:
s.sendto('Hello', ('fdde:ad00:beef:0:0:ff:fe00:e800', 1234))
socket.recv(bufsize)
Usage:
s.recv(128)
socket.recvfrom(bufsize)
This method is useful to know the destination port number of the message received. Returns a tuple of the form: (data, port)
Usage:
s.recvfrom(128)
socket.setsockopt(level, optname, value)
Set the value of the given socket option. The needed symbolic constants are defined in the socket module (SO_*
etc.). In the case of LoRa the values are always integers. Examples:
# configuring the data rate
s.setsockopt(socket.SOL_LORA, socket.SO_DR, 5)
# selecting non-confirmed type of messages
s.setsockopt(socket.SOL_LORA, socket.SO_CONFIRMED, False)
# selecting confirmed type of messages
s.setsockopt(socket.SOL_LORA, socket.SO_CONFIRMED, True)
Socket options are only applicable when the LoRa radio is used in
socket.settimeout(value)
Sets the socket timeout value in seconds. Accepts floating point values.
Usage:
s.settimeout(5.5)
socket.setblocking(flag)
Usage:
s.setblocking(True)