Tools: add mavlink_ulog_streaming.py script to stream ULog via MAVLink to a file

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Beat Küng 2016-10-12 16:56:02 +02:00 committed by Lorenz Meier
parent 7d72f31a29
commit 6999bb3e9a
1 changed files with 248 additions and 0 deletions

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Tools/mavlink_ulog_streaming.py Executable file
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#!/usr/bin/env python
"""
Stream ULog data over MAVLink.
@author: Beat Kueng (beat-kueng@gmx.net)
"""
from __future__ import print_function
import sys, select, os
import datetime
from timeit import default_timer as timer
os.environ['MAVLINK20'] = '1' # The commands require mavlink 2
try:
from pymavlink import mavutil
except:
print("Failed to import pymavlink.")
print("You may need to install it with 'pip install pymavlink'")
exit(-1)
from argparse import ArgumentParser
class MavlinkLogStreaming():
'''Streams log data via MAVLink'''
def __init__(self, portname, baudrate, output_filename, debug=0):
self.baudrate = 0
self._debug = debug
self.buf = ''
self.debug("Connecting with MAVLink to %s ..." % portname)
self.mav = mavutil.mavlink_connection(portname, autoreconnect=True, baud=baudrate)
self.mav.wait_heartbeat()
self.debug("HEARTBEAT OK\n")
self.debug("Locked serial device\n")
self.got_ulog_header = False
self.got_header_section = False
self.ulog_message = []
self.file = open(output_filename,'wb')
self.start_time = timer()
self.last_sequence = -1
self.logging_started = False
self.num_dropouts = 0
def debug(self, s, level=1):
'''write some debug text'''
if self._debug >= level:
print(s)
def start_log(self):
self.mav.mav.command_long_send(self.mav.target_system,
self.mav.target_component,
mavutil.mavlink.MAV_CMD_LOGGING_START, 0,
0, 0, 0, 0, 0, 0, 0)
def stop_log(self):
self.mav.mav.command_long_send(self.mav.target_system,
self.mav.target_component,
mavutil.mavlink.MAV_CMD_LOGGING_STOP, 0,
0, 0, 0, 0, 0, 0, 0)
def read_messages(self):
''' main loop reading messages '''
measure_time_start = timer()
measured_data = 0
while True:
m, first_msg_start, num_drops = self.read_message()
if m is not None:
self.process_streamed_ulog_data(m, first_msg_start, num_drops)
# status output
if self.logging_started:
measured_data += len(m)
measure_time_cur = timer()
dt = measure_time_cur - measure_time_start
if dt > 1:
sys.stdout.write('\rData Rate: {:0.1f} KB/s Drops: {:} \033[K'.format(
measured_data / dt / 1024, self.num_dropouts))
sys.stdout.flush()
measure_time_start = measure_time_cur
measured_data = 0
if not self.logging_started and timer()-self.start_time > 4:
raise Exception('Start timed out. Is the logger running in MAVLink mode?')
def read_message(self):
''' read a single mavlink message, handle ACK & return a tuple of (data, first
message start, num dropouts) '''
m = self.mav.recv_match(type=['LOGGING_DATA_ACKED',
'LOGGING_DATA', 'COMMAND_ACK'], blocking=True,
timeout=0.05)
if m is not None:
self.debug(m, 3)
if m.get_type() == 'COMMAND_ACK':
if m.command == mavutil.mavlink.MAV_CMD_LOGGING_START and \
not self.got_header_section:
if m.result == 0:
self.logging_started = True
print('Logging started. Waiting for Header...')
else:
raise Exception('Logging start failed', m.result)
return None, 0, 0
# m is either 'LOGGING_DATA_ACKED' or 'LOGGING_DATA':
is_newer, num_drops = self.check_sequence(m.sequence)
if is_newer:
if num_drops > 0:
self.num_dropouts += num_drops
if m.get_type() == 'LOGGING_DATA_ACKED':
self.mav.mav.logging_ack_send(m.sequence)
else:
if not self.got_header_section:
print('Header received in {:0.2f}s'.format(timer()-self.start_time))
self.logging_started = True
self.got_header_section = True
self.last_sequence = m.sequence
return m.data[:m.length], m.first_message_offset, num_drops
else:
self.debug('dup/reordered message '+str(m.sequence))
return None, 0, 0
def check_sequence(self, seq):
''' check if a sequence is newer than the previously received one & if
there were dropped messages between the last and this '''
if self.last_sequence == -1:
return True, 0
if seq == self.last_sequence: # duplicate
return False, 0
if seq > self.last_sequence:
# account for wrap-arounds, sequence is 2 bytes
if seq - self.last_sequence > (1<<15): # assume reordered
return False, 0
return True, seq - self.last_sequence - 1
else:
if self.last_sequence - seq > (1<<15):
return True, (1<<16) - self.last_sequence - 1 + seq
return False, 0
def process_streamed_ulog_data(self, data, first_msg_start, num_drops):
''' write streamed data to a file '''
if not self.got_ulog_header: # the first 16 bytes need special treatment
if len(data) < 16: # that's never the case anyway
raise Exception('first received message too short')
self.file.write(bytearray(data[0:16]))
data = data[16:]
self.got_ulog_header = True
if self.got_header_section and num_drops > 0:
if num_drops > 25: num_drops = 25
# write a dropout message. We don't really know the actual duration,
# so just use the number of drops * 10 ms
self.file.write(bytearray([ 2, 0, 79, num_drops*10, 0 ]))
if num_drops > 0:
self.write_ulog_messages(self.ulog_message)
self.ulog_message = []
if first_msg_start == 255:
return # no useful information in this message: drop it
data = data[first_msg_start:]
first_msg_start = 0
if first_msg_start == 255 and len(self.ulog_message) > 0:
self.ulog_message.extend(data)
return
if len(self.ulog_message) > 0:
self.file.write(bytearray(self.ulog_message + data[:first_msg_start]))
self.ulog_message = []
data = self.write_ulog_messages(data[first_msg_start:])
self.ulog_message = data # store the rest for the next message
def write_ulog_messages(self, data):
''' write ulog data w/o integrity checking, assuming data starts with a
valid ulog message. returns the remaining data at the end. '''
while len(data) > 2:
message_length = data[0] + data[1] * 256 + 3 # 3=ULog msg header
if message_length > len(data):
break
self.file.write(bytearray(data[:message_length]))
data = data[message_length:]
return data
def main():
parser = ArgumentParser(description=__doc__)
parser.add_argument('port', metavar='PORT', nargs='?', default = None,
help='Mavlink port name: serial: DEVICE[,BAUD], udp: IP:PORT, tcp: tcp:IP:PORT. Eg: \
/dev/ttyUSB0 or 0.0.0.0:14550. Auto-detect serial if not given.')
parser.add_argument("--baudrate", "-b", dest="baudrate", type=int,
help="Mavlink port baud rate (default=115200)", default=115200)
parser.add_argument("--output", "-o", dest="output", default = '.',
help="output file or directory (default=CWD)")
args = parser.parse_args()
if os.path.isdir(args.output):
filename = datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S.ulg")
filename = os.path.join(args.output, filename)
else:
filename = args.output
print('Output file name: {:}'.format(filename))
if args.port == None:
serial_list = mavutil.auto_detect_serial(preferred_list=['*FTDI*',
"*Arduino_Mega_2560*", "*3D_Robotics*", "*USB_to_UART*", '*PX4*', '*FMU*'])
if len(serial_list) == 0:
print("Error: no serial connection found")
return
if len(serial_list) > 1:
print('Auto-detected serial ports are:')
for port in serial_list:
print(" {:}".format(port))
print('Using port {:}'.format(serial_list[0]))
args.port = serial_list[0].device
print("Connecting to MAVLINK...")
mav_log_streaming = MavlinkLogStreaming(args.port, args.baudrate, filename)
try:
print('Starting log...')
mav_log_streaming.start_log()
mav_log_streaming.read_messages()
print('Stopping log')
mav_log_streaming.stop_log()
except KeyboardInterrupt:
print('Stopping log')
mav_log_streaming.stop_log()
if __name__ == '__main__':
main()