Merge pull request #54 from aj-ptw/wifi

Welcome to Wifi shield!

.gitignore

@@ -63,3 +63,7 @@ target/
 # Matlab
 *.m
 
+# PyCharm
+.idea/*
+.idea/codeStyleSettings.xml
+.idea/vcs.xml

open_bci_ganglion.py

@@ -1,5 +1,5 @@
 """
-Core OpenBCI object for handling connections and samples from the gnaglion board.
+Core OpenBCI object for handling connections and samples from the Ganglion board.
 
 Note that the LIB will take care on its own to print incoming ASCII messages if any (FIXME, BTW).
 

open_bci_wifi.py

@@ -0,0 +1,457 @@
+"""
+Core OpenBCI object for handling connections and samples from the WiFi Shield
+
+Note that the LIB will take care on its own to print incoming ASCII messages if any (FIXME, BTW).
+
+EXAMPLE USE:
+
+def handle_sample(sample):
+  print(sample.channels_data)
+
+wifi = OpenBCIWifi()
+wifi.start(handle_sample)
+
+TODO: Cyton/Ganglion JSON
+TODO: Ganglion Raw
+TODO: Cyton Raw
+
+"""
+import struct
+import time
+import timeit
+import atexit
+import logging
+import numpy as np
+import sys
+import ssdp
+import urllib2
+import xmltodict
+import re
+import asyncore
+import socket
+import requests
+import json
+
+SAMPLE_RATE = 0  # Hz
+
+'''
+#Commands for in SDK
+
+command_stop = "s";
+command_startBinary = "b";
+'''
+
+
+class OpenBCIWifi(object):
+    """
+    Handle a connection to an OpenBCI wifi shield.
+
+    Args:
+      ip_address: The IP address of the WiFi Shield, "None" to attempt auto-detect.
+      shield_name: The unique name of the WiFi Shield, such as `OpenBCI-2AD4`, will use SSDP to get IP address still,
+        if `shield_name` is "None" and `ip_address` is "None", will connect to the first WiFi Shield found using SSDP
+      sample_rate: The sample rate to set the attached board to. If the sample rate picked is not a sample rate the attached
+        board can support, i.e. you send 300 to Cyton, then error will be thrown.
+      log:
+      timeout: in seconds, disconnect / reconnect after a period without new data -- should be high if impedance check
+      max_packets_to_skip: will try to disconnect / reconnect after too many packets are skipped
+    """
+
+    def __init__(self, ip_address=None, shield_name=None, sample_rate=None, log=True, timeout=2,
+                 max_packets_to_skip=20, latency=10000):
+        # these one are used
+        self.log = log  # print_incoming_text needs log
+        self.streaming = False
+        self.timeout = timeout
+        self.max_packets_to_skip = max_packets_to_skip
+        self.impedance = False
+        self.ip_address = ip_address
+        self.shield_name = shield_name
+        self.sample_rate = sample_rate
+        self.latency = latency
+
+        # might be handy to know API
+        self.board_type = "none"
+        # number of EEG channels
+        self.eeg_channels_per_sample = 0
+        self.read_state = 0
+        self.log_packet_count = 0
+        self.packets_dropped = 0
+        self.time_last_packet = 0
+
+        if self.log:
+            print("Welcome to OpenBCI Native WiFi Shield Driver - Please contribute code!")
+
+        self.local_ip_address = self._get_local_ip_address()
+
+        # Intentionally bind to port 0
+        self.local_wifi_server = WiFiShieldServer(self.local_ip_address, 0)
+        self.local_wifi_server_port = self.local_wifi_server.getsockname()[1]
+        if self.log:
+            print("Opened socket on %s:%d" % (self.local_ip_address, self.local_wifi_server_port))
+
+        if ip_address is None:
+            self.find_wifi_shield(wifi_shield_cb=self.on_shield_found)
+        else:
+            self.on_shield_found(ip_address)
+
+    def on_shield_found(self, ip_address):
+        self.ip_address = ip_address
+        self.connect()
+        # Disconnects from board when terminated
+        atexit.register(self.disconnect)
+
+    def loop(self):
+        asyncore.loop()
+
+    def _get_local_ip_address(self):
+        """
+        Gets the local ip address of this computer
+        @returns str Local IP address
+        """
+        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        s.connect(("8.8.8.8", 80))
+        local_ip_address = s.getsockname()[0]
+        s.close()
+        return local_ip_address
+
+    def getBoardType(self):
+        """ Returns the version of the board """
+        return self.board_type
+
+    def setImpedance(self, flag):
+        """ Enable/disable impedance measure """
+        self.impedance = bool(flag)
+
+    def connect(self):
+        """ Connect to the board and configure it. Note: recreates various objects upon call. """
+        if self.ip_address is None:
+            raise ValueError('self.ip_address cannot be None')
+
+        if self.log:
+            print ("Init WiFi connection with IP: " + self.ip_address)
+
+        """
+        Docs on these HTTP requests and more are found:
+        https://app.swaggerhub.com/apis/pushtheworld/openbci-wifi-server/1.3.0
+        """
+
+        res_board = requests.get("http://%s/board" % self.ip_address)
+
+        if res_board.status_code == 200:
+            board_info = res_board.json()
+            if not board_info['board_connected']:
+                raise RuntimeError("No board connected to WiFi Shield. Learn at docs.openbci.com")
+            self.board_type = board_info['board_type']
+            self.eeg_channels_per_sample = board_info['num_channels']
+            if self.log:
+                print("Connected to %s with %s channels" % (self.board_type, self.eeg_channels_per_sample))
+
+        res_tcp_post = requests.post("http://%s/tcp" % self.ip_address,
+                          json={
+                                'ip': self.local_ip_address,
+                                'port': self.local_wifi_server_port,
+                                'output': 'json',
+                                'delimiter': True,
+                                'latency': self.latency
+                                })
+        if res_tcp_post.status_code == 200:
+            tcp_status = res_tcp_post.json()
+            if tcp_status['connected']:
+                if self.log:
+                    print("WiFi Shield to Python TCP Socket Established")
+            else:
+                raise RuntimeWarning("WiFi Shield is not able to connect to local server. Please open an issue.")
+
+    def init_streaming(self):
+        """ Tell the board to record like crazy. """
+        res_stream_start = requests.get("http://%s/stream/start" % self.ip_address)
+        if res_stream_start.status_code == 200:
+            self.streaming = True
+            self.packets_dropped = 0
+            self.time_last_packet = timeit.default_timer()
+        else:
+            raise EnvironmentError("Unable to start streaming. Check API for status code %d on /stream/start" % res_stream_start.status_code)
+
+    def find_wifi_shield(self, shield_name=None, wifi_shield_cb=None):
+        """Detects Ganglion board MAC address -- if more than 1 around, will select first. Needs root privilege."""
+
+        if self.log:
+            print("Try to find WiFi shields on your local wireless network")
+            print("Scanning for 5 seconds nearby devices...")
+
+        list_ip = []
+        list_id = []
+        found_shield = False
+
+        def wifi_shield_found(response):
+            res = urllib2.urlopen(response.location).read()
+            device_description = xmltodict.parse(res)
+            cur_shield_name = str(device_description['root']['device']['serialNumber'])
+            cur_base_url = str(device_description['root']['URLBase'])
+            cur_ip_address = re.findall(r'[0-9]+(?:\.[0-9]+){3}', cur_base_url)[0]
+            list_id.append(cur_shield_name)
+            list_ip.append(cur_ip_address)
+            found_shield = True
+            if shield_name is None:
+                print("Found WiFi Shield %s with IP Address %s" % (cur_shield_name, cur_ip_address))
+                if wifi_shield_cb is not None:
+                    wifi_shield_cb(cur_ip_address)
+            else:
+                if shield_name == cur_shield_name:
+                    if wifi_shield_cb is not None:
+                        wifi_shield_cb(cur_ip_address)
+
+        ssdp_hits = ssdp.discover("urn:schemas-upnp-org:device:Basic:1", timeout=3, wifi_found_cb=wifi_shield_found)
+
+        nb_wifi_shields = len(list_id)
+
+        if nb_wifi_shields < 1:
+            print("No WiFi Shields found ;(")
+            raise OSError('Cannot find OpenBCI WiFi Shield with local name')
+
+        if nb_wifi_shields > 1:
+            print(
+                "Found " + str(nb_wifi_shields) +
+                ", selecting first named: " + list_id[0] +
+                " with IPV4: " + list_ip[0])
+            return list_ip[0]
+
+    def wifi_write(self, output):
+        """
+        Pass through commands from the WiFi Shield to the Carrier board
+        :param output: 
+        :return: 
+        """
+        res_command_post = requests.post("http://%s/command" % self.ip_address,
+                                         json={'command': output})
+        if res_command_post.status_code == 200:
+            ret_val = res_command_post.text
+            if self.log:
+                print(ret_val)
+            return ret_val
+        else:
+            if self.log:
+                print("Error code: %d %s" % (res_command_post.status_code, res_command_post.text))
+            raise RuntimeError("Error code: %d %s" % (res_command_post.status_code, res_command_post.text))
+
+    def getSampleRate(self):
+        return SAMPLE_RATE
+
+    def getNbEEGChannels(self):
+        """Will not get new data on impedance check."""
+        return self.eeg_channels_per_sample
+
+    def start_streaming(self, callback, lapse=-1):
+        """
+        Start handling streaming data from the board. Call a provided callback
+        for every single sample that is processed
+
+        Args:
+          callback: A callback function -- or a list of functions -- that will receive a single argument of the
+              OpenBCISample object captured.
+        """
+        start_time = timeit.default_timer()
+
+        # Enclose callback funtion in a list if it comes alone
+        if not isinstance(callback, list):
+            self.local_wifi_server.set_callback(callback)
+        else:
+            self.local_wifi_server.set_callback(callback[0])
+
+        if not self.streaming:
+            self.init_streaming()
+
+        # while self.streaming:
+        #     # should the board get disconnected and we could not wait for notification anymore, a reco should be attempted through timeout mechanism
+        #     try:
+        #         # at most we will get one sample per packet
+        #         self.waitForNotifications(1. / self.getSampleRate())
+        #     except Exception as e:
+        #         print("Something went wrong while waiting for a new sample: " + str(e))
+        #     # retrieve current samples on the stack
+        #     samples = self.delegate.getSamples()
+        #     self.packets_dropped = self.delegate.getMaxPacketsDropped()
+        #     if samples:
+        #         self.time_last_packet = timeit.default_timer()
+        #         for call in callback:
+        #             for sample in samples:
+        #                 call(sample)
+        #
+        #     if (lapse > 0 and timeit.default_timer() - start_time > lapse):
+        #         self.stop();
+        #     if self.log:
+        #         self.log_packet_count = self.log_packet_count + 1;
+        #
+        #     # Checking connection -- timeout and packets dropped
+        #     self.check_connection()
+
+    def test_signal(self, signal):
+        """ Enable / disable test signal """
+        if signal == 0:
+            self.warn("Disabling synthetic square wave")
+            try:
+                self.wifi_write(']')
+            except Exception as e:
+                print("Something went wrong while setting signal: " + str(e))
+        elif signal == 1:
+            self.warn("Eisabling synthetic square wave")
+            try:
+                self.wifi_write('[')
+            except Exception as e:
+                print("Something went wrong while setting signal: " + str(e))
+        else:
+            self.warn("%s is not a known test signal. Valid signal is 0-1" % signal)
+
+    def set_channel(self, channel, toggle_position):
+        """ Enable / disable channels """
+        try:
+            # Commands to set toggle to on position
+            if toggle_position == 1:
+                if channel is 1:
+                    self.wifi_write('!')
+                if channel is 2:
+                    self.wifi_write('@')
+                if channel is 3:
+                    self.wifi_write('#')
+                if channel is 4:
+                    self.wifi_write('$')
+            # Commands to set toggle to off position
+            elif toggle_position == 0:
+                if channel is 1:
+                    self.wifi_write('1')
+                if channel is 2:
+                    self.wifi_write('2')
+                if channel is 3:
+                    self.wifi_write('3')
+                if channel is 4:
+                    self.wifi_write('4')
+        except Exception as e:
+            print("Something went wrong while setting channels: " + str(e))
+
+    """
+
+    Clean Up (atexit)
+
+    """
+
+    def stop(self):
+        print("Stopping streaming...")
+        self.streaming = False
+        # connection might be already down here
+        try:
+            if self.impedance:
+                print("Stopping with impedance testing")
+                self.wifi_write('Z')
+            else:
+                self.wifi_write('s')
+        except Exception as e:
+            print("Something went wrong while asking the board to stop streaming: " + str(e))
+        if self.log:
+            logging.warning('sent <s>: stopped streaming')
+
+    def disconnect(self):
+        if self.streaming:
+            self.stop()
+
+        # should not try to read/write anything after that, will crash
+
+    """
+
+        SETTINGS AND HELPERS
+
+    """
+
+    def warn(self, text):
+        if self.log:
+            # log how many packets where sent succesfully in between warnings
+            if self.log_packet_count:
+                logging.info('Data packets received:' + str(self.log_packet_count))
+                self.log_packet_count = 0;
+            logging.warning(text)
+        print("Warning: %s" % text)
+
+    def check_connection(self):
+        """ Check connection quality in term of lag and number of packets drop. Reinit connection if necessary. FIXME: parameters given to the board will be lost."""
+        # stop checking when we're no longer streaming
+        if not self.streaming:
+            return
+        # check number of dropped packets and duration without new packets, deco/reco if too large
+        if self.packets_dropped > self.max_packets_to_skip:
+            self.warn("Too many packets dropped, attempt to reconnect")
+            self.reconnect()
+        elif self.timeout > 0 and timeit.default_timer() - self.time_last_packet > self.timeout:
+            self.warn("Too long since got new data, attempt to reconnect")
+            # if error, attempt to reconect
+            self.reconnect()
+
+    def reconnect(self):
+        """ In case of poor connection, will shut down and relaunch everything. FIXME: parameters given to the board will be lost."""
+        self.warn('Reconnecting')
+        self.stop()
+        self.disconnect()
+        self.connect()
+        self.init_streaming()
+
+
+class OpenBCISample(object):
+    """Object encapulsating a single sample from the OpenBCI board."""
+
+    def __init__(self, packet_id, channel_data, aux_data, imp_data):
+        self.id = packet_id
+        self.channel_data = channel_data
+        self.aux_data = aux_data
+        self.imp_data = imp_data
+
+
+class WiFiShieldHandler(asyncore.dispatcher_with_send):
+    def __init__(self, sock, callback=None):
+        asyncore.dispatcher_with_send.__init__(self, sock)
+
+        self.callback = callback
+
+    def handle_read(self):
+        data = self.recv(3000)  # 3000 is the max data the WiFi shield is allowed to send over TCP
+        if len(data) > 2:
+            try:
+                possible_chunks = data.split('\r\n')
+                if len(possible_chunks) > 1:
+                    possible_chunks = possible_chunks[:-1]
+                for possible_chunk in possible_chunks:
+                    if len(possible_chunk) > 2:
+                        chunk_dict = json.loads(possible_chunk)
+                        if 'chunk' in chunk_dict:
+                            for sample in chunk_dict['chunk']:
+                                if self.callback is not None:
+                                    self.callback(sample)
+                        else:
+                            print("not a sample packet")
+            except ValueError as e:
+                print("failed to parse: %s" % data)
+                print e
+            except BaseException as e:
+                print e
+
+
+class WiFiShieldServer(asyncore.dispatcher):
+
+    def __init__(self, host, port, callback=None):
+        asyncore.dispatcher.__init__(self)
+        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.set_reuse_addr()
+        self.bind((host, port))
+        self.listen(5)
+        self.callback = None
+        self.handler = None
+
+    def handle_accept(self):
+        pair = self.accept()
+        if pair is not None:
+            sock, addr = pair
+            print 'Incoming connection from %s' % repr(addr)
+            self.handler = WiFiShieldHandler(sock, self.callback)
+
+    def set_callback(self, callback):
+        self.callback = callback
+        if self.handler is not None:
+            self.handler.callback = callback

scripts/stream_data_wifi.py

@@ -0,0 +1,18 @@
+import sys; sys.path.append('..') # help python find open_bci_v3.py relative to scripts folder
+import open_bci_wifi as bci
+import logging
+
+
+def printData(sample):
+    print sample
+
+
+if __name__ == '__main__':
+    shield_name = 'OpenBCI-E2B6'
+    logging.basicConfig(filename="test.log",format='%(asctime)s - %(levelname)s : %(message)s',level=logging.DEBUG)
+    logging.info('---------LOG START-------------')
+    shield = bci.OpenBCIWifi(shield_name=shield_name, log=True)
+    print("WiFi Shield Instantiated")
+    shield.start_streaming(printData)
+
+    shield.loop()

ssdp.py

@@ -0,0 +1,59 @@
+#   Copyright 2014 Dan Krause
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+import socket
+import httplib
+import StringIO
+
+
+class SSDPResponse(object):
+    class _FakeSocket(StringIO.StringIO):
+        def makefile(self, *args, **kw):
+            return self
+
+    def __init__(self, response):
+        r = httplib.HTTPResponse(self._FakeSocket(response))
+        r.begin()
+        self.location = r.getheader("location")
+        self.usn = r.getheader("usn")
+        self.st = r.getheader("st")
+        self.cache = r.getheader("cache-control").split("=")[1]
+
+    def __repr__(self):
+        return "<SSDPResponse({location}, {st}, {usn})>".format(**self.__dict__)
+
+
+def discover(service, timeout=5, retries=1, mx=3, wifi_found_cb=None):
+    group = ("239.255.255.250", 1900)
+    message = "\r\n".join([
+        'M-SEARCH * HTTP/1.1',
+        'HOST: {0}:{1}',
+        'MAN: "ssdp:discover"',
+        'ST: {st}','MX: {mx}','',''])
+    socket.setdefaulttimeout(timeout)
+    responses = {}
+    for _ in range(retries):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)
+        sock.sendto(message.format(*group, st=service, mx=mx), group)
+        while True:
+            try:
+                response = SSDPResponse(sock.recv(1024))
+                if wifi_found_cb is not None:
+                  wifi_found_cb(response)
+                responses[response.location] = response
+            except socket.timeout:
+                break
+    return responses.values()