Tag version 0.2.4

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>

README.md

@@ -13,7 +13,7 @@ and its python interfaces [pybluez](https://github.com/pybluez/pybluez) to
 handle Bluetooth, and [bluepy](https://github.com/IanHarvey/bluepy) to handle
 Bluetooth Low Energy (BLE) connections. It has been reported that pyscrlink
 connects Scratch 3.0 with micro:bit, LEGO Mindstorms EV3, LEGO WeDo, LEGO
-Boost and Intelino Smart Train.
+Boost, Intelino Smart Train and toio.
 
 To use websockets, pyscrlink requires python version 3.6 or later. If your
 system has python older than version 3.6, install newer version. If your
@@ -42,7 +42,7 @@ Linux distros:
 * elementary OS 5.1 Hera
 
 Browsers:
-* FireFox
+* Firefox
 * Chromium
 
 It was reported that pyscrlink (former bluepy-scratch-link) working with
@@ -51,13 +51,15 @@ following devices and Linux distros.
 Devices:
 * LEGO Mindstorm EV3 by @chrisglencross
 * LEGO WeDo by @zhaowe, @KingBBQ
-* LEGO Boost by @laurentchar, @miguev, @jacquesdt
+* LEGO Boost and compatible devices by @laurentchar, @miguev, @jacquesdt, @n3storm
 * Intelino Smart Train by @ErrorJan
+* toio by @shimodash
 
 Linux distros:
 * Raspbian by @chrisglencross
 * Ubuntu 16.04 @jacquesdt
 * Ubuntu Studio 20.04 @miguev
+* Debian 11 @n3storm
 
 Installation
 ------------
@@ -86,7 +88,8 @@ Installation
     $ pip3 install pyscrlink
     ```
 
-4. For Bluetooth Low Energy (BLE) devices, set bluepy-helper capability.
+4. Set bluepy-helper capability.
+   This step is required for most of devices except LEGO Mindstorm EV3.
 
     ```
     $ bluepy_helper_cap
@@ -99,7 +102,7 @@ Installation
 5. For micro:bit, install Scratch-link hex on your device.
 
     * Download and unzip the [micro:bit Scratch Hex file](https://downloads.scratch.mit.edu/microbit/scratch-microbit-1.1.0.hex.zip).
-    * Flash the micro:bit over USB with the Scratch .Hex File, you will see the
+    * Flash the micro:bit over USB with the Scratch Hex File, you will see the
       five character name of the micro:bit scroll across the screen such as
       'zo9ev'.
 
@@ -158,8 +161,10 @@ Usage
     ```sh
     $ scratch_link
     ```
+    If your device is toio, add "-s 1" option to the scratch_link command. It
+    allows the toio Do Visual Programming to connect to toio automatically.
 
-3. Connect scratch to micro:bit or LEGO Mindstorms:
+3. Connect scratch to the target device such as micro:bit or LEGO Mindstorms:
     * Open FireFox or Chrome. (Make sure to run as the same user for scratch-link python script.)
     * Access [Scratch 3.0](https://scratch.mit.edu/) and create your project.
     * Select the "Add Extension" button.
@@ -187,6 +192,12 @@ In Case You Fail to Connect
 3. If scratch_link.py says "failed to connect to BT device: [Errno 13] Permission denied",
    make sure to pair the bluetooth device to your PC before connecting to Scratch.
 
+4. To connect to multiple devices at the same time, make all the target devices
+   ready for scan at the first device scan. This is important for toio. The toio
+   allows a single project to connect to two toio devices.
+   * When the second device was prepared after the first device was connected, device scan can not find the second device.
+   * To scan and find the second device, disconnect connections for the first device beforehand.
+
 Issus Reporting
 ---------------
 
@@ -195,6 +206,20 @@ Please file issues to [GitHub issue tracker](https://github.com/kawasaki/pyscrli
 Releases
 --------
 
+Release 0.2.4
+
+* Added -s option to specify BLE scan duration
+* Improved README.md
+
+Release 0.2.3
+
+* Fixed eternal loop caused by hostname resolve failure
+
+Release 0.2.2
+
+* Supported multiple device connections for toio
+* Improved session closure handling
+
 Release 0.2.1
 
 * Added libglib to required package list in README.md

pyscrlink/scratch_link.py

@@ -8,12 +8,14 @@ import asyncio
 import pathlib
 import ssl
 import websockets
+import socket
 import json
 import base64
 import logging
 import sys
 import signal
 import traceback
+import argparse
 
 # for Bluetooth (e.g. Lego EV3)
 import bluetooth
@@ -42,6 +44,9 @@ logger.setLevel(logLevel)
 logger.addHandler(handler)
 logger.propagate = False
 
+HOSTNAME="device-manager.scratch.mit.edu"
+scan_seconds=10.0
+
 class Session():
     """Base class for BTSession and BLESession"""
     def __init__(self, websocket, loop):
@@ -343,6 +348,11 @@ class BLESession(Session):
 
     MAX_SCANNER_IF = 3
 
+    found_devices = []
+    nr_connected = 0
+    scan_lock = threading.RLock()
+    scan_started = False
+
     class BLEThread(threading.Thread):
         """
         Separated thread to control notifications to Scratch.
@@ -358,7 +368,7 @@ class BLESession(Session):
                 logger.debug("loop in BLE thread")
                 if self.session.status == self.session.DISCOVERY:
                     logger.debug("send out found devices")
-                    devices = self.session.found_devices
+                    devices = BLESession.found_devices
                     for d in devices:
                         params = { 'rssi': d.rssi }
                         params['peripheralId'] = devices.index(d)
@@ -418,7 +428,6 @@ class BLESession(Session):
     def __init__(self, websocket, loop):
         super().__init__(websocket, loop)
         self.status = self.INITIAL
-        self.found_devices = []
         self.device = None
         self.deviceName = None
         self.perip = None
@@ -426,6 +435,13 @@ class BLESession(Session):
         self.characteristics_cache = []
 
     def close(self):
+        if self.status == self.CONNECTED:
+            BLESession.nr_connected -= 1
+            logger.info(f"BLE session disconnected")
+            logger.debug(f"BLE session connected={BLESession.nr_connected}")
+            if BLESession.nr_connected == 0:
+                logger.info("all BLE sessions disconnected")
+                BLESession.scan_started = False
         self.status = self.DONE
         if self.perip:
             logger.info("disconnect from the BLE peripheral: "
@@ -480,6 +496,31 @@ class BLESession(Session):
                 # ref: https://github.com/LLK/scratch-link/blob/develop/Documentation/BluetoothLE.md
         return False
 
+    def _scan_devices(self, params):
+        global scan_seconds
+        if BLESession.nr_connected > 0:
+            return len(BLESession.found_devices) > 0
+        found = False
+        with BLESession.scan_lock:
+            if not BLESession.scan_started:
+                BLESession.scan_started = True
+                BLESession.found_devices.clear()
+                for i in range(self.MAX_SCANNER_IF):
+                    scanner = Scanner(iface=i)
+                    try:
+                        logger.debug(f"start BLE scan: {scan_seconds} seconds")
+                        devices = scanner.scan(scan_seconds)
+                        for dev in devices:
+                            if self.matches(dev, params['filters']):
+                                BLESession.found_devices.append(dev)
+                                found = True
+                                logger.debug(f"BLE device found with iface #{i}");
+                    except BTLEManagementError as e:
+                        logger.debug(f"BLE iface #{i}: {e}");
+            else:
+                found = len(BLESession.found_devices) > 0
+        return found
+
     def _get_service(self, service_id):
         with self.lock:
             service = self.perip.getServiceByUUID(UUID(service_id))
@@ -532,26 +573,17 @@ class BLESession(Session):
                 logger.error("e.g. $ bluepy_helper_cap")
                 logger.error("e.g. $ sudo bluepy_helper_cap.py")
                 sys.exit(1)
-            found_ifaces = 0
-            for i in range(self.MAX_SCANNER_IF):
-                scanner = Scanner(iface=i)
-                try:
-                    devices = scanner.scan(10.0)
-                    for dev in devices:
-                        if self.matches(dev, params['filters']):
-                            self.found_devices.append(dev)
-                    found_ifaces += 1
-                    logger.debug(f"BLE device found with iface #{i}");
-                except BTLEManagementError as e:
-                    logger.debug(f"BLE iface #{i}: {e}");
-
-            if found_ifaces == 0:
+            found = self._scan_devices(params)
+            if not found:
+                if BLESession.nr_connected > 0:
+                    err_msg = "Can not scan BLE devices. Disconnect other sessions."
+                elif len(BLESession.found_devices) == 0:
                     err_msg = "Can not scan BLE devices. Check BLE controller."
                 logger.error(err_msg);
                 res["error"] = { "message": err_msg }
                 self.status = self.DONE
 
-            if len(self.found_devices) == 0 and not err_msg:
+            if len(BLESession.found_devices) == 0 and not err_msg:
                 err_msg = (f"No BLE device found: {params['filters']}. "
                            "Check BLE device.")
                 res["error"] = { "message": err_msg }
@@ -565,11 +597,12 @@ class BLESession(Session):
 
         elif self.status == self.DISCOVERY and method == 'connect':
             logger.debug("connecting to the BLE device")
-            self.device = self.found_devices[params['peripheralId']]
+            self.device = BLESession.found_devices[params['peripheralId']]
             self.deviceName = self.device.getValueText(0x9) or self.device.getValueText(0x8)
             try:
                 self.perip = Peripheral(self.device)
                 logger.info(f"connected to the BLE peripheral: {self.deviceName}")
+                BLESession.found_devices.remove(self.device)
             except BTLEDisconnectError as e:
                 logger.error(f"failed to connect to the BLE device \"{self.deviceName}\": {e}")
                 self.status = self.DONE
@@ -577,6 +610,8 @@ class BLESession(Session):
             if self.perip:
                 res["result"] = None
                 self.status = self.CONNECTED
+                BLESession.nr_connected += 1
+                logger.debug(f"BLE session connected={BLESession.nr_connected}")
                 self.delegate = self.BLEDelegate(self)
                 self.perip.withDelegate(self.delegate)
                 self._cache_characteristics()
@@ -669,7 +704,8 @@ async def ws_handler(websocket, path):
         await session.handle()
     except Exception as e:
         logger.error(f"Failure in session for web socket path: {path}")
-        logger.error(e)
+        logger.error(f"{type(e).__name__}: {e}")
+        session.close()
 
 def stack_trace():
     print("in stack_trace")
@@ -686,18 +722,20 @@ def stack_trace():
          print(line)
 
 def main():
-    opts = [opt for opt in sys.argv[1:] if opt.startswith("-")]
-    if "-h" in opts:
-        print((f"Usage: {sys.argv[0]} [OPTS]\n"
-               "OPTS:\t-h Show this help.\n"
-               "\t-d Print debug messages."
-        ))
-        sys.exit(1)
-    elif "-d" in opts:
+    global scan_seconds
+    parser = argparse.ArgumentParser(description='start Scratch-link')
+    parser.add_argument('-d', '--debug', action='store_true',
+                        help='print debug messages')
+    parser.add_argument('-s', '--scan_seconds', type=float, default=10.0,
+                        help='specifiy duration to scan BLE devices in seconds')
+    args = parser.parse_args()
+    if args.debug:
         print("Print debug messages")
         logLevel = logging.DEBUG
         handler.setLevel(logLevel)
         logger.setLevel(logLevel)
+    scan_seconds = args.scan_seconds
+    logger.debug(f"set scan_seconds: {scan_seconds}")
 
     # Prepare certificate of the WSS server
     gencert.prep_cert()
@@ -709,7 +747,7 @@ def main():
     ssl_context.load_cert_chain(localhost_cer, localhost_key)
 
     start_server = websockets.serve(
-         ws_handler, "device-manager.scratch.mit.edu", 20110, ssl=ssl_context
+         ws_handler, HOSTNAME, 20110, ssl=ssl_context
     )
 
     while True:
@@ -720,7 +758,13 @@ def main():
         except KeyboardInterrupt as e:
             stack_trace()
             break
+        except socket.gaierror as e:
+            logger.error(f"{type(e).__name__}: {e}")
+            logger.info(f"Check internet connection to {HOSTNAME}. If not "
+                        f"available, add '127.0.0.1 {HOSTNAME}' to /etc/hosts.")
+            break
         except Exception as e:
+            logger.error(f"{type(e).__name__}: {e}")
             logger.info("Restarting scratch-link...")
 
 if __name__ == "__main__":

setup.py

@@ -5,7 +5,7 @@ with open("README.md", "r") as fh:
 
 setuptools.setup(
     name="pyscrlink",
-    version="0.2.1",
+    version="0.2.4",
     author="Shin'ichiro Kawasaki",
     author_email='kawasaki@juno.dti.ne.jp',
     description='Scratch-link for Linux with Python',