uAvaNut Parser

uavanut-ghetto-parser.py

#!/usr/bin/python2
# Joel Stanley <joel@jms.id.au>
# Apache 2.1

import math

# Hard coded start location
start_lon = -34.92454
start_lat = 138.60033

# From http://stackoverflow.com/a/4913653
def haversine(lon1, lat1, lon2, lat2):
    """
    Calculate the great circle distance between two points
    on the earth (specified in decimal degrees)
    """
    # convert decimal degrees to radians
    lon1, lat1, lon2, lat2 = map(math.radians, [lon1, lat1, lon2, lat2])

    # haversine formula
    dlon = lon2 - lon1
    dlat = lat2 - lat1
    a = math.sin(dlat/2)**2 + math.cos(lat1) * math.cos(lat2) * math.sin(dlon/2)**2
    c = 2 * math.asin(math.sqrt(a))
    r = 6371 # Radius of earth in kilometers. Use 3956 for miles
    return c * r


nums = []
dist = []
with open('log.txt') as fh:
    for line in fh.readlines():
        if line.count("Current RSSI: "):
            nums.append(int(line.split(":")[1]))

        if line.count("Got Packet: $$LORA1"):
            lon = float(line.split(",")[3])
            lat = float(line.split(",")[4])
            dist.append(haversine(start_lon, start_lat, lon, lat) * 1000)

import matplotlib.pyplot as plt
import numpy as np

fig, ax1 = plt.subplots()
ax1.plot(nums)
ax1.set_ylabel('RSSI (dBm)')

step = int(len(nums)/len(dist))

ax2 = ax1.twinx()
x = np.arange(0.0, len(nums), step)[:-1]
ax2.plot(x, dist, 'r-')
ax2.set_ylabel('Distance from base (m)')

plt.title("RSSI for Mark's walk to the shop")
plt.show()