Buffer too small problem LoRa Lopy 4

[ferfersan6]

Hey all. Maybe it is a very simple question, but I am very newbie with Python and Pycom. I am trying to send a simple doube with LoRa, from one Lopy 4 to other Lopy 4. I try to unpack the message on the receiving Lopy with struct.unpack('d',recpaquete), but it says the buffer is too small. I put the code:

from network import LoRa
import socket
import time
import struct

lora = LoRa(mode=LoRa.LORA, frequency=863000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)

while True:
    recpaquete = s.recv(64)
    numero = struct.unpack('d',recpaquete)
    time.sleep(5)

I have tried with several numbers (512, 1024, 2048...) but doesn't work. This Lopy just receive dates.
The code from the other lopy is:

from network import LoRa
import socket
import time

lora = LoRa(mode=LoRa.LORA, frequency=863000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)

while True:
    paquete = struct.pack('d',57.3)
    s.send(paquete)
    time.sleep(5)

Hope you can help me. Thanks in advance!!

[ferfersan6]

@robert-hh Wow, it works!!!! Thank you man, you are my hero!!. Seriously, I am so grateful.

[robert-hh]

@ferfersan6 The socket is set non noblocking. So s.recv() returns immediately if nothing was received. The return value is b"", with a buffer size of 0. Since the unpack requires at least 8 bytes, you get an error. So you have to add something like:

from network import LoRa
import socket
import time
import struct

lora = LoRa(mode=LoRa.LORA, frequency=863000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)

while True:
    recpaquete = s.recv(64)
    if len(recpaquete) >= 8:
        numero = struct.unpack('d',recpaquete)
    time.sleep(5)

[ferfersan6]

@robert-hh I can't even receive a message, can't run or upload it on the Lopy. The error is in the title: "Buffer too small"

[ferfersan6]

This post is deleted!

[robert-hh]

@ferfersan6 said in Buffer too small problem LoRa Lopy 4:
How long is the message you actually receive? Tell it by
print(len(recpaquete))
It should be 8 bytes.