├── UpBoardSwitch.JPG
├── MultiCameraEthernet.png
├── AlwaysRunningServer.bash
├── setup.py
├── .gitignore
├── README.md
├── EtherSenseClient.py
├── EtherSenseServer.py
└── LICENSE


/UpBoardSwitch.JPG:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/krejov100/EtherSense/HEAD/UpBoardSwitch.JPG


--------------------------------------------------------------------------------
/MultiCameraEthernet.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/krejov100/EtherSense/HEAD/MultiCameraEthernet.png


--------------------------------------------------------------------------------
/AlwaysRunningServer.bash:
--------------------------------------------------------------------------------
1 | #!/bin/bash
2 | # this statement checks if there is an instance of the EtherSenseServer running
3 | if [[ ! `ps -eaf | grep "python EtherSenseServer.py" | grep -v grep` ]]; then
4 | # if not, EtherSenseServer is started with the PYTHONPATH set due to cron not passing Env 
5 |     PYTHONPATH=$HOME/.local/lib/python2.7/site-packages python EtherSenseServer.py
6 | fi
7 | 


--------------------------------------------------------------------------------
/setup.py:
--------------------------------------------------------------------------------
 1 | # install the dependancies from pip
 2 | try:
 3 |     from pip import main as pipmain
 4 | except:
 5 |     from pip._internal import main as pipmain
 6 | pipmain(['install', 'numpy'])
 7 | pipmain(['install', 'python-crontab'])
 8 | pipmain(['install', 'opencv-python'])
 9 | pipmain(['install', 'pyrealsense2'])
10 | pipmain(['install', 'cron_descriptor'])
11 | 
12 | # using python-crontab, setup a job that is ran on the minute to check if the server is running. 
13 | # https://pypi.org/project/python-crontab/
14 | from crontab import CronTab
15 | #using the system crontab file as sudo is required for librealsense aquisition
16 | system_cron = CronTab(tabfile='/etc/crontab', user=False)
17 | #requires the shell enviroment as ./AlwaysRunningServer.bash 
18 | system_cron.env['SHELL'] = '/bin/bash'
19 | job = system_cron.new(command="cd /home/$(ls /home/)/EtherSense; ./AlwaysRunningServer.bash >> /tmp/error.log 2>&1", user='root')
20 | job.every_reboot()
21 | i = 0
22 | #this while loop means that the are entrys in the cron file for each 5 sec interval
23 | while i < 60:
24 |     #the cron job is cd to the EtherSense dir then run AlwaysRunningServer.bash, logging to /temp/error.log
25 |     #have to use this $(ls /home/) to find home dir, assuming no other user spaces.
26 |     job = system_cron.new(command="sleep %i; cd /home/$(ls /home/)/EtherSense; ./AlwaysRunningServer.bash >> /tmp/error.log 2>&1"%i, user='root')
27 | 
28 |     # this line sets the frequance of server checking, stars for all time slices means every minute
29 |     job.setall('* * * * *')
30 |     system_cron.write()
31 |     i += 5
32 | print('cron job set to run ' + job.description())
33 | 
34 | 
35 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
  1 | # Byte-compiled / optimized / DLL files
  2 | __pycache__/
  3 | *.py[cod]
  4 | *$py.class
  5 | 
  6 | # C extensions
  7 | *.so
  8 | 
  9 | # Distribution / packaging
 10 | .Python
 11 | build/
 12 | develop-eggs/
 13 | dist/
 14 | downloads/
 15 | eggs/
 16 | .eggs/
 17 | lib/
 18 | lib64/
 19 | parts/
 20 | sdist/
 21 | var/
 22 | wheels/
 23 | *.egg-info/
 24 | .installed.cfg
 25 | *.egg
 26 | MANIFEST
 27 | 
 28 | # PyInstaller
 29 | #  Usually these files are written by a python script from a template
 30 | #  before PyInstaller builds the exe, so as to inject date/other infos into it.
 31 | *.manifest
 32 | *.spec
 33 | 
 34 | # Installer logs
 35 | pip-log.txt
 36 | pip-delete-this-directory.txt
 37 | 
 38 | # Unit test / coverage reports
 39 | htmlcov/
 40 | .tox/
 41 | .coverage
 42 | .coverage.*
 43 | .cache
 44 | nosetests.xml
 45 | coverage.xml
 46 | *.cover
 47 | .hypothesis/
 48 | .pytest_cache/
 49 | 
 50 | # Translations
 51 | *.mo
 52 | *.pot
 53 | 
 54 | # Django stuff:
 55 | *.log
 56 | local_settings.py
 57 | db.sqlite3
 58 | 
 59 | # Flask stuff:
 60 | instance/
 61 | .webassets-cache
 62 | 
 63 | # Scrapy stuff:
 64 | .scrapy
 65 | 
 66 | # Sphinx documentation
 67 | docs/_build/
 68 | 
 69 | # PyBuilder
 70 | target/
 71 | 
 72 | # Jupyter Notebook
 73 | .ipynb_checkpoints
 74 | 
 75 | # pyenv
 76 | .python-version
 77 | 
 78 | # celery beat schedule file
 79 | celerybeat-schedule
 80 | 
 81 | # SageMath parsed files
 82 | *.sage.py
 83 | 
 84 | # Environments
 85 | .env
 86 | .venv
 87 | env/
 88 | venv/
 89 | ENV/
 90 | env.bak/
 91 | venv.bak/
 92 | 
 93 | # Spyder project settings
 94 | .spyderproject
 95 | .spyproject
 96 | 
 97 | # Rope project settings
 98 | .ropeproject
 99 | 
100 | # mkdocs documentation
101 | /site
102 | 
103 | # mypy
104 | .mypy_cache/
105 | 
106 | #pycharm
107 | .idea/
108 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # EtherSense
 2 | Ethernet client and server for RealSense using python's Asyncore.
 3 | 
 4 | ## Prerequisites
 5 | Installation and Setup of Server:
 6 | These steps assume a fresh install of Ubuntu 18.04 on an UpBoard but has also been tested on an Intel NUC.
 7 | 
 8 | ```
 9 | sudo apt-get update; sudo apt-get upgrade; 
10 | 
11 | sudo apt-get install python
12 | 
13 | sudo apt-get install python-pip  
14 | 
15 | sudo apt-get install git
16 | ```
17 | 
18 | Clone the repo then run:
19 | 
20 | ```
21 | sudo python setup.py
22 | ```
23 | 
24 | This will first install the pip dependencies, followed by the creation of cronjobs in the /etc/crontab file that maintains an instance of the Server running whenever the device is powered. 
25 | 
26 | ## Overview
27 | Mulicast broadcast is used to establish connections to servers that are present on the network. 
28 | Once a server receives a request for connection from a client, Asyncore is used to establish a TCP connection for each server. 
29 | Frames are collected from the camera using librealsense pipeline. It is then resized and send in smaller chucks as to conform with TCP.
30 | 
31 | ### UpBoard PoE 
32 | Below shows use of a PoE switch and PoE breakout devices(avalible from online retailers) powering each dedicated UpBoard: 
33 | This configuration should allow for a number of RealSense cameras to be connected over distances greater then 30m 
34 | ![Example Image](https://github.com/krejov100/EtherSense/blob/master/UpBoardSwitch.JPG)
35 | The 5 RealSense cameras are connected to each UpBoard using the provided USB3 cables.
36 | 
37 | ### Client Window
38 | Below shows the result of having connected to five cameras over the local network: 
39 | ![Example Image](https://github.com/krejov100/EtherSense/blob/master/MultiCameraEthernet.png)
40 | The window titles indicate the port which the frames are being received over.
41 | 
42 | ## Error Logging
43 | Errors are piped to a log file stored in /tmp/error.log as part of the command that is setup in /etc/crontab
44 | 
45 | ## NOTES
46 | 
47 | ### Power Considerations
48 | The UpBoards require a 5v 4Amp power supply. When using PoE breakout adaptors I have found some stability issues, for example the device kernel can crash when the HDMI port is connected. As such I recommend running the UpBoard as a headless server when using PoE. 
49 | 
50 | ### Network bandwidth
51 | It is currently very easy to saturate the bandwidth of the Ethernet connection I have tested 5 servers connected to the same client without issue beyond limited framerate:
52 | 
53 | cfg.enable_stream(rs.stream.depth, 640, 480, rs.format.z16, 30)
54 | 
55 | self.decimate_filter.set_option(rs.option.filter_magnitude, 2)
56 | 
57 | There are a number of strategies that can be used to increase this bandwidth but are left to the user for brevity and the specific tradeoff for your application, these include:
58 | 
59 | Transmitting frames using UDP and allowing for frame drop, this requires implementation of packet ordering.
60 | 
61 | Reducing the depth channel to 8bit.
62 | 
63 | Reducing the resolution further.
64 | 
65 | The addition of compression, either frame wise or better still temporal.
66 | 
67 | Local recording of the depth data into a buffer, with asynchronous frame transfer.
68 |  
69 | ## TroubleShooting Tips
70 | 
71 | I first of all suggest installing and configuring openssh-server on each of the UpBoards allowing remote connection from the client machine.
72 | 
73 | Check that the UpBoards are avalible on the local network using "nmap -sP 192.168.2.*"
74 | 
75 | Check that the server is running on the UpBoard using "ps -eaf | grep "python EtherSenseServer.py"
76 | 
77 | Finally check the log file at /tmp/error.log
78 | 
79 | There might still be some conditions where the Server is running but not in a state to transmit, help in narrowing these cases would be much appreciated. 
80 | 
81 | 


--------------------------------------------------------------------------------
/EtherSenseClient.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/python
  2 | import pyrealsense2 as rs
  3 | import sys, getopt
  4 | import asyncore
  5 | import numpy as np
  6 | import pickle
  7 | import socket
  8 | import struct
  9 | import cv2
 10 | 
 11 | 
 12 | print('Number of arguments:', len(sys.argv), 'arguments.')
 13 | print('Argument List:', str(sys.argv))
 14 | mc_ip_address = '224.0.0.1'
 15 | local_ip_address = '192.168.0.1'
 16 | port = 1024
 17 | chunk_size = 4096
 18 | 
 19 | def main(argv):
 20 |     multi_cast_message(mc_ip_address, port, 'EtherSensePing')
 21 |         
 22 | 
 23 | #UDP client for each camera server 
 24 | class ImageClient(asyncore.dispatcher):
 25 |     def __init__(self, server, source):   
 26 |         asyncore.dispatcher.__init__(self, server)
 27 |         self.address = server.getsockname()[0]
 28 |         self.port = source[1]
 29 |         self.buffer = bytearray()
 30 |         self.windowName = self.port
 31 |         # open cv window which is unique to the port 
 32 |         cv2.namedWindow("window"+str(self.windowName))
 33 |         self.remainingBytes = 0
 34 |         self.frame_id = 0
 35 |        
 36 |     def handle_read(self):
 37 |         if self.remainingBytes == 0:
 38 |             # get the expected frame size
 39 |             self.frame_length = struct.unpack('<I', self.recv(4))[0]
 40 |             # get the timestamp of the current frame
 41 |             self.timestamp = struct.unpack('<d', self.recv(8))
 42 |             self.remainingBytes = self.frame_length
 43 |         
 44 |         # request the frame data until the frame is completely in buffer
 45 |         data = self.recv(self.remainingBytes)
 46 |         self.buffer += data
 47 |         self.remainingBytes -= len(data)
 48 |         # once the frame is fully recived, process/display it
 49 |         if len(self.buffer) == self.frame_length:
 50 |             self.handle_frame()
 51 | 
 52 |     def handle_frame(self):
 53 |         # convert the frame from string to numerical data
 54 |         imdata = pickle.loads(self.buffer)
 55 |         bigDepth = cv2.resize(imdata, (0,0), fx=2, fy=2, interpolation=cv2.INTER_NEAREST) 
 56 |         cv2.putText(bigDepth, str(self.timestamp), (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.8, (65536), 2, cv2.LINE_AA)
 57 |         cv2.imshow("window"+str(self.windowName), bigDepth)
 58 |         cv2.waitKey(1)
 59 |         self.buffer = bytearray()
 60 |         self.frame_id += 1
 61 |     def readable(self):
 62 |         return True
 63 | 
 64 |     
 65 | class EtherSenseClient(asyncore.dispatcher):
 66 |     def __init__(self):
 67 |         asyncore.dispatcher.__init__(self)
 68 |         self.server_address = ('', 1024)
 69 |         # create a socket for TCP connection between the client and server
 70 |         self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
 71 |         self.socket.settimeout(5)
 72 |         
 73 |         self.bind(self.server_address) 	
 74 |         self.listen(10)
 75 | 
 76 |     def writable(self): 
 77 |         return False # don't want write notifies
 78 | 
 79 |     def readable(self):
 80 |         return True
 81 |         
 82 |     def handle_connect(self):
 83 |         print("connection recvied")
 84 | 
 85 |     def handle_accept(self):
 86 |         pair = self.accept()
 87 |         #print(self.recv(10))
 88 |         if pair is not None:
 89 |             sock, addr = pair
 90 |             print ('Incoming connection from %s' % repr(addr))
 91 |             # when a connection is attempted, delegate image receival to the ImageClient 
 92 |             handler = ImageClient(sock, addr)
 93 | 
 94 | def multi_cast_message(ip_address, port, message):
 95 |     # send the multicast message
 96 |     multicast_group = (ip_address, port)
 97 |     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
 98 |     connections = {}
 99 |     try:
100 |         # Send data to the multicast group
101 |         print('sending "%s"' % message + str(multicast_group))
102 |         sent = sock.sendto(message.encode(), multicast_group)
103 |    
104 |         # defer waiting for a response using Asyncore
105 |         client = EtherSenseClient()
106 |         asyncore.loop()
107 | 
108 |         # Look for responses from all recipients
109 |         
110 |     except socket.timeout:
111 |         print('timed out, no more responses')
112 |     finally:
113 |         print(sys.stderr, 'closing socket')
114 |         sock.close()
115 | 
116 | if __name__ == '__main__':
117 |     main(sys.argv[1:])
118 | 


--------------------------------------------------------------------------------
/EtherSenseServer.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/python
  2 | import pyrealsense2 as rs
  3 | import sys, getopt
  4 | import asyncore
  5 | import numpy as np
  6 | import pickle
  7 | import socket
  8 | import struct
  9 | import cv2
 10 | 
 11 | 
 12 | print('Number of arguments:', len(sys.argv), 'arguments.')
 13 | print('Argument List:', str(sys.argv))
 14 | mc_ip_address = '224.0.0.1'
 15 | port = 1024
 16 | chunk_size = 4096
 17 | #rs.log_to_console(rs.log_severity.debug)
 18 | 
 19 | def getDepthAndTimestamp(pipeline, depth_filter):
 20 |     frames = pipeline.wait_for_frames()
 21 |     # take owner ship of the frame for further processing
 22 |     frames.keep()
 23 |     depth = frames.get_depth_frame()
 24 |     if depth:
 25 | 	depth2 = depth_filter.process(depth)
 26 | 	# take owner ship of the frame for further processing
 27 | 	depth2.keep()
 28 | 	# represent the frame as a numpy array
 29 |         depthData = depth2.as_frame().get_data()        
 30 | 	depthMat = np.asanyarray(depthData)
 31 | 	ts = frames.get_timestamp()
 32 |         return depthMat, ts
 33 |     else:
 34 |         return None, None
 35 | def openPipeline():
 36 |     cfg = rs.config()
 37 |     cfg.enable_stream(rs.stream.depth, 640, 480, rs.format.z16, 30)
 38 |     pipeline = rs.pipeline()
 39 |     pipeline_profile = pipeline.start(cfg)
 40 |     sensor = pipeline_profile.get_device().first_depth_sensor()
 41 |     return pipeline
 42 | 
 43 | class DevNullHandler(asyncore.dispatcher_with_send):
 44 | 
 45 |     def handle_read(self):
 46 |         print(self.recv(1024))
 47 | 
 48 |     def handle_close(self):
 49 |         self.close()
 50 |            
 51 | 		
 52 | class EtherSenseServer(asyncore.dispatcher):
 53 |     def __init__(self, address):
 54 |         asyncore.dispatcher.__init__(self)
 55 |         print("Launching Realsense Camera Server")
 56 | 	try:
 57 |             self.pipeline = openPipeline()
 58 |         except:
 59 |             print("Unexpected error: ", sys.exc_info()[1])
 60 |             sys.exit(1)
 61 |         self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
 62 |         print('sending acknowledgement to', address)
 63 |         
 64 | 	# reduce the resolution of the depth image using post processing
 65 |         self.decimate_filter = rs.decimation_filter()
 66 |         self.decimate_filter.set_option(rs.option.filter_magnitude, 2)
 67 |         self.frame_data = ''
 68 |         self.connect((address[0], 1024))
 69 |         self.packet_id = 0        
 70 | 
 71 |     def handle_connect(self):
 72 |         print("connection received")
 73 | 
 74 |     def writable(self):
 75 |         return True
 76 | 
 77 |     def update_frame(self):
 78 | 	depth, timestamp = getDepthAndTimestamp(self.pipeline, self.decimate_filter)
 79 |         if depth is not None:
 80 | 	    # convert the depth image to a string for broadcast
 81 |             data = pickle.dumps(depth)
 82 | 	    # capture the lenght of the data portion of the message	
 83 |             length = struct.pack('<I', len(data))
 84 | 	    # include the current timestamp for the frame
 85 |             ts = struct.pack('<d', timestamp)
 86 | 	    # for the message for transmission
 87 |             self.frame_data = ''.join([length, ts, data])
 88 | 
 89 |     def handle_write(self):
 90 | 	# first time the handle_write is called
 91 |         if not hasattr(self, 'frame_data'):
 92 |             self.update_frame()
 93 | 	# the frame has been sent in it entirety so get the latest frame
 94 |         if len(self.frame_data) == 0:
 95 | 	    self.update_frame()
 96 |         else:
 97 | 	    # send the remainder of the frame_data until there is no data remaining for transmition
 98 |             remaining_size = self.send(self.frame_data)
 99 |             self.frame_data = self.frame_data[remaining_size:]
100 | 	
101 | 
102 |     def handle_close(self):
103 |         self.close()
104 |             
105 | 
106 | class MulticastServer(asyncore.dispatcher):
107 |     def __init__(self, host = mc_ip_address, port=1024):
108 |         asyncore.dispatcher.__init__(self)
109 |         server_address = ('', port)
110 |         self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
111 |         self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
112 |         self.bind(server_address) 	
113 | 
114 |     def handle_read(self):
115 |         data, addr = self.socket.recvfrom(42)
116 |         print('Recived Multicast message %s bytes from %s' % (data, addr))
117 | 	# Once the server recives the multicast signal, open the frame server
118 |         EtherSenseServer(addr)
119 |         print(sys.stderr, data)
120 | 
121 |     def writable(self): 
122 |         return False # don't want write notifies
123 | 
124 |     def handle_close(self):
125 |         self.close()
126 | 
127 |     def handle_accept(self):
128 |         channel, addr = self.accept()
129 |         print('received %s bytes from %s' % (data, addr))
130 | 
131 | 
132 | def main(argv):
133 |     # initalise the multicast receiver 
134 |     server = MulticastServer()
135 |     # hand over excicution flow to asyncore
136 |     asyncore.loop()
137 |    
138 | if __name__ == '__main__':
139 |     main(sys.argv[1:])
140 | 
141 | 


--------------------------------------------------------------------------------
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