Has anyone successfully used lora.nvram_save() and restore?

  • Hi Everyone !
    I am confused with using lora.nvram_save and restore. I am using in my program but I am not sure where and how to use. Can someone guide me in this. I will put my code here.
    Thank you in Advance.

    from network import LoRa
    import socket
    import time
    import ubinascii
    store =["26012FF8", "26012FF7", "f82f0126" ]
    #creating a OTAA connection
    app_eui = ubinascii.unhexlify('0004A30B00000000')
    app_key = ubinascii.unhexlify('DE71C5CA71E05F92FE3B000000000')

    Join a network with OTAA

    lora.join(activation=LoRa.OTAA, auth=(app_eui, app_key), timeout=0)

    #wait until the module to join
    while not lora.has_joined():
    print('Not yet joined...')

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

    #set lorawan datarate
    s.setsockopt(socket.SOL_LORA, socket.SO_DR, 5)

    #make the socket blocking

    s.send(bytes([0x01, 0x02, 0x03]))

    s.send(bytes([0x01, 0x02, 0x03]))


    while True:

    lora = LoRa(mode=LoRa.LORA, region=LoRa.EU868, sf = 7, frequency = 868500000)
    # create a raw LoRa socket
    s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
    rx_data = s.recv(64)
    dev_addr = rx_data[1:5]
    print("Dev-Addr: ", binascii.hexlify(dev_addr))
    x = 0
    for x in range(0, 3):
        if(binascii.unhexlify(store[x]) == dev_addr):
            # get any data received...
            #rx_data = s.recv(64)
            # sending data to server with sf = 12
            lora = LoRa(mode=LoRa.LORAWAN, region=LoRa.EU868,  sf = 12)        
            # send some data
            print('data sent')
            print('Not OK')

    lora = LoRa(mode=LoRa.LORAWAN)

    #join a network using OTAA
    lora.join(activation=LoRa.OTAA, auth=(app_eui, app_key), timeout=0)

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

    #doing uplink
    s.send(bytes([0x01, 0x02, 0x03]))

    #doing downlink
    data = s.recv(64)
    first4 = data[0:4]
    second4 = data[5:9]

    And here, I am trying to save my OTAA connection and at last I am restoring those keys to do uplink again to get some downlinks.

  • @jcaron oh thank you. I will do that. And I need a small help from you. In this code, I am trying to start my downlink once in a day. So I am using this code.

    import time

    a = time.localtime()

    hour = a.tm_hour
    minutes = a.tm_min

    if hour == 10 and minutes == 40:
    print('{0}:{1}'.format(hour, minutes))

    But it's not working properly. Do I have to change some conditions ?

  • @harish-kumar you only need to use nvram_save/restore if you use deep sleep (or cut power to the LoPy), which is not the case here.

    Just keep the same Lora object and socket and don’t join again...

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