#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ Created on Sun Dec 27 20:43:40 2020 @author: DJ2LS """ # CRC aller payloads via XOR scrambeln und dann eine CRC8 mitsenden import logging import crcengine import threading import time import static import modem import other modem = modem.RF() crc_algorithm = crcengine.new('crc16-ccitt-false') #load crc16 library static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_PAYLOAD_PER_FRAME - 6 #class ARQ(): # # def receive(bytes_in): # # print("TEST") def data_received(data_in): ARQ_N_RX_BURSTS = int.from_bytes(bytes(data_in[:1]), "big") - 10 static.ARQ_RX_BUFFER.append(data_in) #append data to RX BUFFER if len(static.ARQ_RX_BUFFER) == ARQ_N_RX_BURSTS: #if received bursts are equal to burst number in frame burst_total_payload = bytearray() for n_raw_frame in range(0,len(static.ARQ_RX_BUFFER)): burst_frame = static.ARQ_RX_BUFFER[n_raw_frame] #get burst frame burst_payload = burst_frame[3:] #remove frame type and burst CRC burst_total_payload = burst_total_payload + burst_payload #stick bursts together print(burst_total_payload) burst_payload_crc = crc_algorithm(burst_total_payload) burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big') print(burst_payload_crc) if burst_payload_crc == data_in[1:3]: #IF burst payload crc and input crc are equal print(data_in[1:3]) print("CRC EQUAL") logging.info("TX | SENDING ACK [" + str(data_in[1:3]) +"]") #BUILDING ACK FRAME ----------------------------------------------- ack_frame = b'\7' + bytes(burst_payload_crc) ack_buffer = bytearray(static.ARQ_PAYLOAD_PER_FRAME) ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send #TRANSMIT ACK FRAME ----------------------------------------------- modem.Transmit(ack_buffer) static.ARQ_RX_BUFFER = [] else: #IF burst payload crc and input crc are NOT equal print("CRC NOT EQUAL!!!!!") print(data_in[1:3]) static.ARQ_RX_BUFFER = [] def ack_received(): logging.info("TX | ACK RCVD!") static.ACK_TIMEOUT = 1 #Force timer to stop waiting static.ACK_RECEIVED = 1 #Force data loops of TNC to stop and continue with next frame # static.ARQ_ACK_WAITING_FOR_ID def transmit(data_out): static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_PAYLOAD_PER_FRAME - 3 static.TX_BUFFER = [data_out[i:i+static.ARQ_PAYLOAD_PER_FRAME] for i in range(0, len(data_out), static.ARQ_PAYLOAD_PER_FRAME)] # split incomming bytes to size of 30bytes - arq payload static.TX_BUFFER_SIZE = len(static.TX_BUFFER) logging.info("TX | TOTAL PAYLOAD BYTES/FRAMES TO SEND: " + str(len(data_out)) + " / " + str(static.TX_BUFFER_SIZE)) for n_raw_frame in range(0, static.TX_BUFFER_SIZE, static.ARQ_TX_N_FRAMES): # LOOP THROUGH DATA LIST with steps = ARQ_TX_N_FRAMES print("N_RAW_FRAME: " + str(n_raw_frame)) # ----------- GENERATE PAYLOAD CRC FOR ARQ_TX_N_FRAMES burst_total_payload = bytearray() for i in range(static.ARQ_TX_N_FRAMES): #bytearray(b'111111111111111111111111222222222222222222222222') # we need to make sure, payload data is always as long as static.ARQ_PAYLOAD_PER_FRAME beacuse of CRC! burst_raw_payload = static.TX_BUFFER[n_raw_frame + i] burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME) burst_payload[:len(burst_raw_payload)] = burst_raw_payload # set buffersize to length of data which will be send burst_total_payload = burst_total_payload + burst_payload burst_payload_crc = crc_algorithm(burst_total_payload) burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big') print(burst_payload_crc) static.ARQ_ACK_WAITING_FOR_ID = burst_payload_crc #set the global variable so we know for which ACK we are waiting for #-------------------- BUILD ARQBURSTS arqburst = [] for i in range(static.ARQ_TX_N_FRAMES): frame_type = 10 + static.ARQ_TX_N_FRAMES frame_type = bytes([frame_type]) payload_data = bytes(static.TX_BUFFER[n_raw_frame + i]) arqframe = frame_type + burst_payload_crc + payload_data buffer = bytearray(static.FREEDV_PAYLOAD_PER_FRAME) # create TX buffer buffer[:len(arqframe)] = arqframe # set buffersize to length of data which will be send arqburst.append(buffer) #--------------------------------------------- N ATTEMPTS TO SEND BURSTS IF ACK FAILS for static.TX_N_RETRIES in range(static.TX_N_MAX_RETRIES): static.ACK_RECEIVED = 0 # ----------------------- Loop through ARQ FRAMES BUFFER with N = Numbers of frames which will be send at once for n in range(static.ARQ_TX_N_FRAMES): logging.info("TX | SENDING BURST " + str(n+1) + " / " + str(static.ARQ_TX_N_FRAMES)) modem.Transmit(arqburst[n]) time.sleep(2) #modem.RF.Transmit(arqburst[n]) print(arqburst[n]) # --------------------------- START TIMER ---> IF TIMEOUT REACHED, ACK_TIMEOUT = 1 static.ACK_TIMEOUT = 0 timer = threading.Timer(static.ACK_TIMEOUT_SECONDS * static.ARQ_TX_N_FRAMES, other.timeout) timer.start() # --------------------------- WHILE TIMEOUT NOT REACHED AND NO ACK RECEIVED --> LISTEN logging.info("TX | WAITING FOR ACK") while static.ACK_TIMEOUT == 0 and static.ACK_RECEIVED == 0: static.MODEM_RECEIVE = True else: logging.info("TX | ACK TIMEOUT - SENDING AGAIN") #--------------- BREAK LOOP IF ACK HAS BEEN RECEIVED if static.ACK_RECEIVED == 1: #static.TX_N_RETRIES = 3 break # ----------- if no ACK received and out of retries.....stop frame sending if static.ACK_RECEIVED == 0: logging.info("TX | NO ACK RECEIVED | FRAME NEEDS TO BE RESEND!") break #-------------------------BREAK TX BUFFER LOOP IF ALL PACKETS HAVE BEEN SENT if n_raw_frame == static.TX_BUFFER_SIZE: break logging.info("TX | BUFFER EMPTY")