15 Commits

Author SHA1 Message Date
Shin'ichiro Kawasaki
7cc9ccac2e Tag version 0.2.5
Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-11-21 14:25:56 +09:00
Shin'ichiro Kawasaki
4558ea43df BLESession: handle device UUIDs as list
In the debug for the issue #30, it turned out that the bluepy API
ScanEntry.getValueText() for adtypes may return multiple UUIDs
concatenated with comma. Current code assumes that the API returns
single UUID, then multiple UUIDs cause the "Error: Non-hexadecimal digit
found" for the comma.

To fix it, replace ScanEntry.getValueText() call with getValue(), and
handle the result as a list of UUIDs. Also rename the helper function
_get_dev_uuid() to _get_dev_uuids() accordingly.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-11-21 14:21:50 +09:00
Shin'ichiro Kawasaki
641b84a86e BLESession: Enrich logs for device UUID check
To debug the GitHub issue #30, add more debug logs to functions to check
UUID.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-11-21 14:21:42 +09:00
Shin'ichiro Kawasaki
e6d63a5c97 Tag version 0.2.4
Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-10-16 11:09:28 +09:00
Shin'ichiro Kawasaki
6f7da4f720 README.md: Add description about "-s 1" option for toio
For toio, it is recommended to add "-s 1" option to scratch_link
command. It reduces scan wait duration, and allows toio Do Visual
Programming to connect toio devices automatically. Document it for toio
users.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-10-16 11:09:28 +09:00
Shin'ichiro Kawasaki
32da72492f scratch_link.py: Add -s option to specify BLE scan duration
Pyscrlink scans BLE devices for 10 seconds. This is a safe number to
cover various environments and devices. However, this is too long for
specific devices. One example is toio. Toio's Visual Programming
environment has automated connection to toio devices via Scratch-link,
at it assumes that the scan finishes with shorter time. To allow users
to specify shorter scan duration, add -s, or --scan_seconds option.

To simplify this new option support, utilize argparse library. Rewrite
option parser with argparse.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-10-10 15:32:06 +09:00
Shin'ichiro Kawasaki
1af4baa7d6 README.md: Clarify bluepy-helper capability setup requirement
@n3storm reported that it is not clear which device is BLE, and requires
bluepy-helper capability setup. Improve description to note that most of
devices require the setup since BLE devices are getting the majority.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-09-25 09:38:37 +09:00
Néstor Díaz Valencia
39587b497b Update README.md 2021-09-25 09:30:55 +09:00
Néstor Díaz Valencia
f506bbcaab Update README.md 2021-09-25 09:30:55 +09:00
Shin'ichiro Kawasaki
9265086b12 Tag version 0.2.3
Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-05-08 21:04:03 +09:00
Shin'ichiro Kawasaki
58a60c94db scratch_link.py: Avoid eternal loop by hostname resolve failure
When the address of device-manager.scratch.mit.edu can not be resolved,
scratch_link.py catches the exception for the resolve failure and
restarts itself. This results in eternal loop.

To avoid the eternal loop, catch the resolve failure, print error
message and break the loop. Also improve the error message for the other
exceptions caught in the loop.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-05-08 20:32:05 +09:00
Shin'ichiro Kawasaki
ea1109cee2 Tag version 0.2.2
Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-05-03 19:42:50 +09:00
Shin'ichiro Kawasaki
f4af270fbc README.md: Improve description for multiple devices
Describe limitation for multiple device connections in "In Case You Fail
to Connect" section. Also, mention about toio support and improved a few
descriptions.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-05-03 19:33:06 +09:00
Shin'ichiro Kawasaki
1b92af0f0a BLESession: Support multiple connections
When one pyscrlink uses tries to connect multiple devices at the same
time, the user can connect to the first device without problem. However,
the device scan for the second device causes connection loss for the
first connected device. As discussed in its GitHub issue #357 [1], it is
the limitation of bluepy as of today. This limitation is critical for
pyscrlink to bridge toio[2] and its own scratch[3], because the toio
scratch allows to connect two toio devices to single scratch project.

[1] https://github.com/IanHarvey/bluepy/issues/357
[2] https://www.sony.com/en/SonyInfo/design/stories/toio/
[3] https://github.com/toio/toio-visual-programming/

To bridge multiple devices by pyscrlink, keep references to multiple
devices at the first device scan. Assuming that the user prepares all of
the target devices ready at the device scan, pyscrlink can find the all
devices and keep references to them. When the user requests scan for the
second device, pyscrlink does not invoke the device scan. Instead, it
returns the references to the device it keeps. With this approach, the
disconnection by device scan can be avoided.

In detail, add BLESession.found_devices to keep the found devices and
share across multiple BLESessions. Add BLESession.nr_connected to count
connected sessions. While connected sessions exist, do not scan and
refer the list to return the found device list. Also refactor out device
scan part to a private function _scan_devices().

Note that the user must prepare all devices ready before the first scan.
The devices prepared after the first can not be found since pyscrlink
does not invoke scan. User must disconnect all devices to have pyscrlink
scan devices again.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-05-03 19:33:06 +09:00
Shin'ichiro Kawasaki
c206f7a5c5 BLESession: Close session on Exception
When an exception is thrown during a session, still the session no
longer works, but still keeps connection. With this status, following
device scan can not find the device. This symptom was observed when
micro:bit with scratch-microbit.hex is connected to "micro:bit MORE" and
BTLEException is thrown. Another symptom observed is the Scratch web
page closed and websocket connection slows ConnectionClosedOK exception.

To avoid the device scan failure, close the session when an exception is
caught. Also improve error message for the exception.

Signed-off-by: Shin'ichiro Kawasaki <kawasaki@juno.dti.ne.jp>
2021-05-03 19:32:49 +09:00
3 changed files with 125 additions and 49 deletions

View File

@@ -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 +206,24 @@ Please file issues to [GitHub issue tracker](https://github.com/kawasaki/pyscrli
Releases
--------
Release 0.2.5
* Fixed handling of multiple UUIDs for LEGO Boost
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

View File

@@ -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: "
@@ -437,12 +453,14 @@ class BLESession(Session):
def __del__(self):
self.close()
def _get_dev_uuid(self, dev):
def _get_dev_uuids(self, dev):
for adtype in self.SERVICE_CLASS_UUID_ADTYPES:
service_class_uuid = dev.getValueText(adtype)
if service_class_uuid:
logger.debug(self.SERVICE_CLASS_UUID_ADTYPES[adtype])
return UUID(service_class_uuid)
service_class_uuids = dev.getValue(adtype)
if service_class_uuids:
for u in service_class_uuids:
a = self.SERVICE_CLASS_UUID_ADTYPES[adtype]
logger.debug(f"service class uuid for {a}/{adtype}: {u}")
return service_class_uuids
return None
def matches(self, dev, filters):
@@ -455,15 +473,16 @@ class BLESession(Session):
for s in f['services']:
logger.debug(f"service to check: {s}")
given_uuid = s
logger.debug(f"given: {given_uuid}")
dev_uuid = self._get_dev_uuid(dev)
if not dev_uuid:
logger.debug(f"given UUID: {given_uuid} hash={UUID(given_uuid).__hash__()}")
dev_uuids = self._get_dev_uuids(dev)
if not dev_uuids:
continue
logger.debug(f"dev: {dev_uuid}")
logger.debug(given_uuid == dev_uuid)
if given_uuid == dev_uuid:
logger.debug("match...")
return True
for u in dev_uuids:
logger.debug(f"dev UUID: {u} hash={u.__hash__()}")
logger.debug(given_uuid == u)
if given_uuid == u:
logger.debug("match...")
return True
if 'namePrefix' in f:
# 0x08: Shortened Local Name
deviceName = dev.getValueText(0x08)
@@ -480,6 +499,31 @@ 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 +576,17 @@ 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:
err_msg = "Can not scan BLE devices. Check BLE controller."
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 +600,12 @@ 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 +613,8 @@ 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 +707,8 @@ 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 +725,20 @@ 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 +750,7 @@ 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 +761,13 @@ 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__":

View File

@@ -5,7 +5,7 @@ with open("README.md", "r") as fh:
setuptools.setup(
name="pyscrlink",
version="0.2.1",
version="0.2.5",
author="Shin'ichiro Kawasaki",
author_email='kawasaki@juno.dti.ne.jp',
description='Scratch-link for Linux with Python',