def _udp_thread(self): while True: try: data, src = self.sock.recvfrom(1024) _token = data[1:3] _type = data[3] if _type == PUSH_ACK: print("Push ack") elif _type == PULL_ACK: print("Pull ack") elif _type == PULL_RESP: self.dwnb += 1 ack_error = TX_ERR_NONE tx_pk = json.loads(data[4:]) tmst = tx_pk["txpk"]["tmst"] t_us = tmst - time.ticks_us() - 5000 if t_us < 0: t_us += 0xFFFFFFFF if t_us < 20000000: self.uplink_alarm = Timer.Alarm(handler=lambda x: self._send_down_link(binascii.a2b_base64(tx_pk["txpk"]["data"]), tx_pk["txpk"]["tmst"] - 10, tx_pk["txpk"]["datr"], int(tx_pk["txpk"]["freq"] * 1000000)), us=t_us) print("Downlink") else: ack_error = TX_ERR_TOO_LATE print("Downlink timestamp error!, t_us:", t_us) self._ack_pull_rsp(_token, ack_error) print("Pull rsp") except socket.timeout: pass except OSError as e: if e.errno == errno.EAGAIN: pass else: print("UDP recv OSError Exception") except Exception: print("UDP recv Exception") # Wait before trying to receive again time.sleep(0.025)