Merge pull request #130 from aj-ptw/add-exp-python

Add exp python

Author: AJ Keller

examples/python/handoff.py

@@ -0,0 +1,117 @@
+import json
+import sys
+import numpy as np
+import time
+import zmq
+
+
+class Interface:
+    def __init__(self, verbose=False):
+        context = zmq.Context()
+        self._socket = context.socket(zmq.PAIR)
+        self._socket.connect("tcp://localhost:3004")
+
+        self.verbose = verbose
+
+        if self.verbose:
+            print "Client Ready!"
+
+        # Send a quick message to tell node process we are up and running
+        self.send(json.dumps({
+            'action': 'started',
+            'command': 'status',
+            'message': time.time()*1000.0
+        }))
+
+    def send(self, msg):
+        """
+        Sends a message to TCP server
+        :param msg: str
+            A string to send to node TCP server, could be a JSON dumps...
+        :return: None
+        """
+        if self.verbose:
+            print '<- out ' + msg
+        self._socket.send(msg)
+        return
+
+    def recv(self):
+        """
+        Checks the ZeroMQ for data
+        :return: str
+            String of data
+        """
+        return self._socket.recv()
+
+
+class RingBuffer(np.ndarray):
+    """A multidimensional ring buffer."""
+
+    def __new__(cls, input_array):
+        obj = np.asarray(input_array).view(cls)
+        return obj
+
+    def __array_finalize__(self, obj):
+        if obj is None:
+            return
+
+    def __array_wrap__(self, out_arr, context=None):
+        return np.ndarray.__array_wrap__(self, out_arr, context)
+
+    def append(self, x):
+        """Adds element x to the ring buffer."""
+        x = np.asarray(x)
+        self[:, :-1] = self[:, 1:]
+        self[:, -1] = x
+
+
+def main(argv):
+    nb_chan = 8
+    verbose = True
+
+    # Create a new python interface.
+    interface = Interface(verbose=verbose)
+    # Signal buffer
+    signal = RingBuffer(np.zeros((nb_chan + 1, 2500)))
+
+    while True:
+        msg = interface.recv()
+        try:
+            dicty = json.loads(msg)
+            action = dicty.get('action')
+            command = dicty.get('command')
+            message = dicty.get('message')
+
+            if command == 'sample':
+                if action == 'process':
+                    # Do sample processing here
+                    try:
+                        if type(message) is not dict:
+                            print "sample is not a dict", message
+                            raise ValueError
+                        # Get keys of sample
+                        data = np.zeros(9)
+
+                        data[:-1] = message.get('channelData')
+                        data[-1] = message.get('timeStamp')
+
+                        # Add data to end of ring buffer
+                        signal.append(data)
+
+                        print message.get('sampleNumber')
+                    except ValueError as e:
+                        print e
+            elif command == 'status':
+                if action == 'active':
+                    interface.send(json.dumps({
+                        'action': 'alive',
+                        'command': 'status',
+                        'message': time.time() * 1000.0
+                    }))
+
+        except BaseException as e:
+            print e
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])

examples/python/index.js

@@ -0,0 +1,212 @@
+/**
+ * This is an example from the readme.md
+ * On windows you should run with PowerShell not git bash.
+ * Install
+ *   [nodejs](https://nodejs.org/en/)
+ *
+ * To run:
+ *   change directory to this file `cd examples/debug`
+ *   do `npm install`
+ *   then `npm start`
+ */
+var OpenBCIBoard = require('openbci').OpenBCIBoard;
+var port_pub = 'tcp://127.0.0.1:3004';
+var zmq = require('zmq-prebuilt');
+var socket = zmq.socket('pair');
+var simulate = true; // Sends synthetic data
+var debug = false; // Pretty print any bytes in and out... it's amazing...
+var verbose = true; // Adds verbosity to functions
+
+var ourBoard = new OpenBCIBoard({
+  simulate: simulate,
+  simulatorFirmwareVersion: 'v2',
+  debug: debug,
+  verbose: verbose
+});
+
+var sampleRate = 250; // Default to 250, ALWAYS verify with a call to `.sampleRate()` after 'ready' event!
+var timeSyncPossible = false;
+var resyncPeriodMin = 1;
+var secondsInMinute = 60;
+var resyncPeriod = ourBoard.sampleRate() * resyncPeriodMin * secondsInMinute;
+
+ourBoard.autoFindOpenBCIBoard().then(portName => {
+  if (portName) {
+    /**
+     * Connect to the board with portName
+     * i.e. ourBoard.connect(portName).....
+     */
+    // Call to connect
+    ourBoard.connect(portName)
+      .then(() => {
+        ourBoard.on('ready', () => {
+
+          // Get the sample rate after 'ready'
+          sampleRate = ourBoard.sampleRate();
+          // Find out if you can even time sync, you must be using v2 and this is only accurate after a `.softReset()` call which is called internally on `.connect()`. We parse the `.softReset()` response for the presence of firmware version 2 properties.
+          timeSyncPossible = ourBoard.usingVersionTwoFirmware();
+
+          if (timeSyncPossible) {
+            ourBoard.streamStart()
+              .catch(err => {
+                console.log(`stream start: ${err}`);
+              });
+          } else {
+            console.log('not able to time sync');
+          }
+        })
+      })
+      .catch(err => {
+        console.log(`connect: ${err}`);
+      });
+  } else {
+    /** Unable to auto find OpenBCI board */
+    console.log('Unable to auto find OpenBCI board');
+  }
+});
+
+var sampleFunc = sample => {
+  if (sample._count % resyncPeriod === 0) {
+    ourBoard.syncClocksFull()
+      .then(syncObj => {
+        // Sync was successful
+        if (syncObj.valid) {
+          // Log the object to check it out!
+          console.log(`timeOffset`, syncObj.timeOffsetMaster);
+        } else {
+          // Retry it
+          console.log(`Was not able to sync... retry!`);
+        }
+      });
+  }
+
+  if (sample.timeStamp) { // true after the first successful sync
+    if (sample.timeStamp < 10 * 60 * 60 * 1000) { // Less than 10 hours
+      console.log(`Bad time sync ${sample.timeStamp}`);
+    } else {
+      sendToPython({
+        action: 'process',
+        command: 'sample',
+        message: sample
+      });
+    }
+  }
+};
+
+// Subscribe to your functions
+ourBoard.on('sample', sampleFunc);
+
+// ZMQ fun
+
+socket.bind(port_pub, function (err) {
+  if (err) throw err;
+  console.log(`bound to ${port_pub}`);
+});
+
+/**
+ * Used to send a message to the Python process.
+ * @param  {Object} interProcessObject The standard inter-process object.
+ * @return {None}
+ */
+var sendToPython = (interProcessObject, verbose) => {
+  if (verbose) {
+    console.log(`<- out ${JSON.stringify(interProcessObject)}`);
+  }
+  if (socket) {
+    socket.send(JSON.stringify(interProcessObject));
+  }
+};
+
+var receiveFromPython = (raw_data) => {
+  try {
+    let body = JSON.parse(raw_data); // five because `resp `
+    processInterfaceObject(body);
+  } catch (err) {
+    console.log('in -> ' + 'bad json');
+  }
+};
+
+socket.on('message', receiveFromPython);
+
+var sendStatus = () => {
+  sendToPython({'action': 'active', 'message': 'ready', 'command': 'status'}, true);
+};
+
+sendStatus();
+
+/**
+ * Process an incoming message
+ * @param  {String} body   A stringify JSON object that shall be parsed.
+ * @return {None}
+ */
+var processInterfaceObject = (body) => {
+  switch (body.command) {
+    case 'status':
+      processStatus(body);
+      break;
+    default:
+      unrecognizedCommand(body);
+      break;
+  }
+};
+
+/**
+ * Used to process a status related command from TCP IPC.
+ * @param  {Object} body
+ * @return {None}
+ */
+var processStatus = (body) => {
+  switch (body.action) {
+    case 'started':
+      console.log(`python started @ ${body.message}ms`);
+      break;
+    case 'alive':
+      console.log(`python duplex communication test completed @ ${body.message}ms`);
+      break;
+    default:
+      unrecognizedCommand(body);
+      break;
+  }
+};
+
+function unrecognizedCommand (body) {
+  console.log(`unrecognizedCommand ${body}`);
+}
+
+function exitHandler (options, err) {
+  if (options.cleanup) {
+    if (verbose) console.log('clean');
+    /** Do additional clean up here */
+  }
+  if (err) console.log(err.stack);
+  if (options.exit) {
+    if (verbose) console.log('exit');
+    ourBoard.disconnect().catch(console.log);
+  }
+}
+
+if (process.platform === "win32") {
+  const rl = require("readline").createInterface({
+    input: process.stdin,
+    output: process.stdout
+  });
+
+  rl.on("SIGINT", function () {
+    process.emit("SIGINT");
+  });
+}
+
+// do something when app is closing
+process.on('exit', exitHandler.bind(null, {
+  cleanup: true
+}));
+
+// catches ctrl+c event
+process.on('SIGINT', exitHandler.bind(null, {
+  exit: true
+}));
+
+// catches uncaught exceptions
+process.on('uncaughtException', exitHandler.bind(null, {
+  exit: true
+}));

examples/python/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "python",
+  "version": "1.0.0",
+  "description": "node to python example",
+  "main": "index.js",
+  "scripts": {
+    "start": "concurrently --kill-others \"python handoff.py\" \"node index.js\"",
+    "start-node": "node index.js",
+    "start-verbose": "concurrently --kill-others \"python handoff.py -v\" \"node index.js\"",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [
+    "python",
+    "openbci",
+    "node"
+  ],
+  "author": "AJ Keller",
+  "license": "MIT",
+  "dependencies": {
+    "openbci": "^1.4.2",
+    "zmq-prebuilt": "^2.1.0"
+  },
+  "devEngines": {
+    "node": "<=6.x",
+    "npm": ">=3.x"
+  },
+  "devDependencies": {
+    "concurrently": "^3.1.0"
+  }
+}