lopy4 connecting to a relay (class c)

Reply to lopy4 connecting to a relay (class c) on Wed, 26 Sep 2018 16:30:43 GMT

abhishek2101 — Wed, 26 Sep 2018 16:30:43 GMT

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 ?

Reply to lopy4 connecting to a relay (class c) on Thu, 27 Sep 2018 11:50:00 GMT

abhishek2101 — Thu, 27 Sep 2018 11:50:00 GMT

@abhishek2101 any help would be much appreciated.

Reply to lopy4 connecting to a relay (class c) on Thu, 27 Sep 2018 12:20:33 GMT

robert-hh — Thu, 27 Sep 2018 12:20:33 GMT

@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

Reply to lopy4 connecting to a relay (class c) on Thu, 27 Sep 2018 14:37:24 GMT

jcaron — Thu, 27 Sep 2018 14:37:24 GMT

@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.

Reply to lopy4 connecting to a relay (class c) on Fri, 28 Sep 2018 15:35:40 GMT

Charly86 — Fri, 28 Sep 2018 15:35:40 GMT

@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)