lopy4 connecting to a relay (class c)

[abhishek2101]

Hi

is lopy4 a class C device ?

I am looking to connect a relay and send commands to start AC loads. Can somebody guide me how to do this ?

[Charly86]

@abhishek2101 I've got some Lopy4 acting as a class C, and it works fine (mine are always powered)

but you need a server capable of sending downlink of course.

I'm sorry I can't share any code but looks like something

LoRa(mode=LoRa.LORAWAN, public=True, tx_retries=3, device_class=LoRa.CLASS_C)

while (not lora.has_joined()):
    time.sleep(0.1)

lsock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
lsock.setsockopt(socket.SOL_LORA, socket.SO_DR, 5)
lsock.setsockopt(socket.SOL_LORA, socket.SO_CONFIRMED, False)
lsock.setblocking(False)
                
while true:
      data, port = self.lsock.recvfrom(32)
      lg = len (data)
      if lg > 0:
          print("Downlink Port={:d} Size={:d} Payload={}".format(port, lg, hexlify(data).upper()) )
      time.sleep(0.1)

[jcaron]

@abhishek2101 The LoPy4 is supposed to support Class C, though I have never tested this.

Note that

• you need the network (LNS and gateways) to support class C devices, which is quite uncommon I believe
• a class C device needs to be always listening, so no deep sleep or anything like that, it most probably can't run on batteries and needs to be powered all the time.

[robert-hh]

@abhishek2101 There is the parameter device_class in the lora.init() call or the constructor, where you can set the device class. The default is class A, but you can also set device class C.
See https://docs.pycom.io/firmwareapi/pycom/network/lora

[abhishek2101]

@abhishek2101 any help would be much appreciated.