Script to parse MegaDump logs from galileod (fitbit), and try to extract interesting information from it.

analysedump.py

#!/usr/bin/env python

import sys
import time

def readdata():
    """ input is from stdin in the format of lines of long string starting
    with a tab ('\t') representing the hexadcimal representation of the data
    (megadump)"""
    d = []
    for line in sys.stdin:
        if line[0] != '\t':
            continue
        line = line.strip()
        for i in range(0, len(line), 2):
            d.append(int(line[i:i+2], 16))
    return d

def a2s(array):
    """ array of int to string """
    return ''.join([chr(c) for c in array])

def a2x(array):
    """ array of int to hex representation """
    return ' '.join(["%02X" % i for i in array])

def a2lsbi(array):
    """ array to int (LSB first) """
    integer = 0
    for i in range(len(array)-1, -1, -1):
        integer *= 256
        integer += array[i]
    #    print a2x(array), hex(integer)
    return integer

def a2msbi(array):
    """ array to int (MSB first) """
    integer = 0
    for i in range(len(array)):
        integer *= 256
        integer += array[i]
    return integer

def first_field(array, start):
    """ 'daily' is highly hypothetical """
    # first timestamp
    index = start
    while array[index] != 0xc0:
        if array[index] == 0xdb:
            index += 1
        tstamp = a2lsbi(array[index:index+4])
        print time.strftime("%x %X", time.localtime(tstamp))
        index += 4
        print "\t%s" % a2x(array[index:index+11])
        index += 11
    return index

def minutely(array, start):
    """ this analyses the minute-by-minute information
    """
    index = start
    tstamp = 0
    while array[index] != 0xc0:
        if not (array[index] & 0x80):
            tstamp = a2msbi(array[index:index+4])
        else:
            if array[index] != 0x81:
                index += 1
            print time.strftime("%x %X", time.localtime(tstamp)), a2x(array[index:index+4])
            tstamp += 60
        index += 4
    
    return index

def stairs(array, start):
    """ Looks like stairs informations are put here """
    index = start
    tstamp = 0
    while array[index] != 0xc0:
        if not (array[index] & 0x80):
            tstamp = a2msbi(array[index:index+4])
            index += 4
        else:
            if array[index] != 0x80:
                #print a2x([array[index]])
                index += 1
            print time.strftime("%x %X", time.localtime(tstamp)), a2x(array[index:index+2])
            tstamp += 60
            index += 2
    return index

def daily(array, start):
    index = start
    while array[index] != 0xc0:
        tstamp = a2lsbi(array[index:index+4])
        index += 4
        if array[index] == 0xdb:
            index += 1
        print time.strftime("%x %X", time.localtime(tstamp)), a2x(array[index:index + 12])
        index += 12
    return index

def main():
    data = readdata()
 
    # empirical value
    index = 60

    # Greetings
    print "Greetings: '%s'" % a2s(data[index:index+10])
    index += 10

    # Cheering
    print "Cheering"
    for i in range(3):
        print "'%s'" % a2s(data[index:index+10])
        index += 10

    # 'C0' looks like a magical value there ...
    next_index = data.index(0xc0, index)
    print a2x(data[index:next_index])
    index = next_index
    
    assert(data[index:index+4] == [0xc0, 0xdb, 0xdc, 0xdd])
    index += 4

    print "First field"
    index = first_field(data, index)
    
    assert(data[index:index+5] == [0xc0, 0xc0, 0xdb, 0xdc, 0xdd])
    index += 5

    print "Second field"
    index = minutely(data, index)

    assert(data[index:index+5] == [0xc0, 0xc0, 0xdb, 0xdc, 0xdd])
    index += 5

    print "Third field"
    index = stairs(data, index)
    
    assert(data[index:index+5] == [0xc0, 0xc0, 0xdb, 0xdc, 0xdd])
    index += 5

    print "Fourth field"
    index = daily(data, index)
    
    print "Remainder"
    print a2x(data[index:])

    
if __name__ == "__main__":
    main()

This moved to https://bitbucket.org/benallard/galileo/src/default/analysedump.py