main.py

#/usr/bin/env python3

import binascii
import sys
import struct
import socket
import argparse
import time

# All of the sentence-specific decoding stuff.
import sentences

# Set up command-line arguments.
parser = argparse.ArgumentParser(formatter_class = argparse.ArgumentDefaultsHelpFormatter,
	description = "Decode and display data from a Potensic d85 drone.")
parser.add_argument("--ip", help = "IPv4 address to listen on", default = "0.0.0.0", type = str)
parser.add_argument("--drone", help = "IPv4 address of the drone", default = "192.168.99.1", type = str)
parser.add_argument("--port", help = "port to listen on", default = 8001, type = int)
parser.add_argument("--recvbuf", help = "size of UDP receive buffer", default = 4096, type = int)
parser.add_argument("--refresh", help = "data refresh rate (milliseconds)", default = 10, type = int)
parser.add_argument("--all", help = "show all sentences that are received instead of just the meaningful ones", action = "store_true")
args = parser.parse_args()

# Connect to the network.
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.setblocking(0)
sock.bind((args.ip, args.port))

DSP = sentences.DroneSentenceProcessor()

print("Ready, waiting for data...")

# Main loop. Reads sentences and decodes them.
while True:
	try:
		sentence, drone_addr = sock.recvfrom(args.recvbuf)
		# Only listen to packets sent by the drone.
		if drone_addr[0] == args.drone:
			# Decode basic data common to all sentences.
			DSP.feed(sentence)
	# If there is no data available...
	except BlockingIOError:
		# ...sleep to lower CPU load. Without sleep(), the program ties up an entire
		# core throwing BlockingIOError as fast as it can, over and over again.
		# args.refresh is in milliseconds, sleep() takes seconds.
		time.sleep(args.refresh / 1000.0)