Interrupting a bluetooth connection in a programmable way - python-3.x

I am wanting to interrupt this bluetooth connect in a programmable way in python if I can. I have read many articles online and cannot seem to find a way to send an interrupt, other than a keyboard interrupt, to the client_sock, clientInfo = server_sock.accept() so that this line of code stops its bluetooth connectivity. The end game is to use my GUI side of this program by implementing a "Stop Connection" button in my GUI to halt the bluetooth connection. Is there a way to do that in python3 at all, or is this something that can only be handled via command line???
size = 1024
while True:
self.bluetooth_information.append("Waiting for connection")
self.bluetooth_information.append(str(datetime.now().time()))
client_sock, clientInfo = server_sock.accept()
try:
data = client_sock.recv(size) # receives data from client
if len(data) == 0:
break
client_sock.send(self.parse.process_data(data)) # Echo response back to client
# except bluetooth.btcommon.BluetoothError:
# pass
if self.stop:
client_sock.close()
server_sock.close()
self.stop = False
self.bluetooth_information.clear()
break
except KeyboardInterrupt:
client_sock.close()
server_sock.close()
break

Related

Using Multiprocessing to create a pyserial .write() , .read() processes in python3

Devices used : Beaglebone_AI and 2 STM32 nucleos connected to the Beaglebone AI using USB hub.
The idea:
The Beaglebone uses a python3 script that uses multiprocessing and pyserial to create 3 processes:
Process 1 - Request a string from STM32 #1 and adds the string to FIFO Queue
Process 2 - Function that writes all responses from STM32 #2
Process 3 - .get() from FIFO Queue go through a switch statement to process either strings from STM32 #1 or user commands.
The Problem:
- It seems like sometimes pyserial .write() dosnt send the user command or data.
can Pyserial .read() and .write() at the same time ??
This is my function process that prints everything that it receives:
def writeall(serial_port, q2):
all_bytes = []
while True:
try:
bytesToRead = serial_port.inWaiting()
data = serial_port.read(bytesToRead).decode('utf-8')
if not data:
pass
else:
if data == '\n':
data = ''.join(all_bytes)
#Print to screen everything
print(data, end = '\033[K\n\n', flush=True)
all_bytes.clear()
#serial_port.reset_input_buffer()
else:
#append all the bytes that are being received
all_bytes.append(str(data))
except (OSError,serial.serialutil.SerialException) as e:
print(f'Actuator Controller: {e}') ```
**This is my serial port config:**
``` def opening_port(q2):
global serial_port
try:
a =""
for p in ports:
#if 'COM9' in p.device: #for windows
if "066BFF343633464257245637" in p.serial_number: #my nucleo
a = p.device
# Port initialization
serial_port = serial.Serial(
port= a,
baudrate=9600,
bytesize= serial.EIGHTBITS,
parity= serial.PARITY_NONE,
stopbits= serial.STOPBITS_ONE,
timeout= 1)
# Discarding anything in the I/O buffer.
#serial_port.reset_output_buffer()
#serial_port.reset_input_buffer()
return serial_port ```
**ANd this is pyserial .write() function that uses the same port as the writeall function process**
``` def write_comand(comand):
try:
#Reset the buffer before sending a command
serial_port.reset_output_buffer()
serial_port.reset_input_buffer()
serial_port.write(bytes(comand,'utf8'))
# Testing wheter the Queue is getting the user commands and if we are actually sending them
if '3E12' in str(comand):
pass
else :
print(f" cmd sent {comand}\n")
#time.sleep(0.005)
except (OSError,serial.serialutil.SerialException) as e:
print (f" There was a problem communicating with AC: {e}\n")
print('Resetting Actuator Controller...\n')
write_comand('B6D8\r')# reset command ```

Can't Send Command to BLE Device Philips Hue Bulb (Connection Drops)

I am trying to turn my bluetooth Hue bulb on/off and change brightness using my Raspberry Pi 4B. The bulb is on, and I have successfully connected to it using bluez. When I try to run 'char-write-req 0x0027 01' to turn it on, I get this message:
GLib-WARNING **: 22:53:34.807: Invalid file descriptor
I can see that the connection is successful, but whenever I try to write a value to it, I just get this message and it disconnects. Running bluetoothctl 5.50. I have seen the patch conversation here: https://www.spinics.net/lists/linux-bluetooth/msg67617.html. But I am not sure it applies and I also wouldn't even know how to apply it. Can someone please help me!
EDIT I ditched the gatttool and am using bluetoothctl to connect to the bulb and menu gatt to send commands to it.
I figured out that the characteristic for toggling the light on and off is 932c32bd-0002-47a2-835a-a8d455b859dd (For my Philips Hue A19). After connecting to the bulb, I was able to select this attribute and use 'write 01' to turn it on and 'write 00' to turn it off.
The brightness characteristic is 932c32bd-0002-47a2-835a-a8d455b859dd. When I read, it outputs 'fe', which is HEX for 254. This is the highest brightness setting, which it was already set to. I can use 'write ' where value ranges from 1-254 to change the brightness.
Using acquire-write in bluetoothctl is typically not the correct command. read and write are what you want.
After starting starting bluetoothctl I would expect the series of commands to be:
connect <Address of bulb>
menu gatt
select-attribute 932c32bd-0002-47a2-835a-a8d455b859dd
write 1
write 0
If you wanted to script this, then below is a Python3 script that I would expect to turn the bulb on then off.
from time import sleep
from pydbus import SystemBus
BLUEZ_SERVICE = 'org.bluez'
BLUEZ_DEV_IFACE = 'org.bluez.Device1'
BLUEZ_CHR_IFACE = 'org.bluez.GattCharacteristic1'
class Central:
def __init__(self, address):
self.bus = SystemBus()
self.mngr = self.bus.get(BLUEZ_SERVICE, '/')
self.dev_path = self._from_device_address(address)
self.device = self.bus.get(BLUEZ_SERVICE, self.dev_path)
self.chars = {}
def _from_device_address(self, addr):
"""Look up D-Bus object path from device address"""
mng_objs = self.mngr.GetManagedObjects()
for path in mng_objs:
dev_addr = mng_objs[path].get(BLUEZ_DEV_IFACE, {}).get('Address', '')
if addr.casefold() == dev_addr.casefold():
return path
def _get_device_chars(self):
mng_objs = self.mngr.GetManagedObjects()
for path in mng_objs:
chr_uuid = mng_objs[path].get(BLUEZ_CHR_IFACE, {}).get('UUID')
if path.startswith(self.dev_path) and chr_uuid:
self.chars[chr_uuid] = self.bus.get(BLUEZ_SERVICE, path)
def connect(self):
"""
Connect to device.
Wait for GATT services to be resolved before returning
"""
self.device.Connect()
while not self.device.ServicesResolved:
sleep(0.5)
self._get_device_chars()
def disconnect(self):
"""Disconnect from device"""
self.device.Disconnect()
def char_write(self, uuid, value):
"""Write value to given GATT characteristic UUID"""
if uuid.casefold() in self.chars:
self.chars[uuid.casefold()].WriteValue(value, {})
else:
raise KeyError(f'UUID {uuid} not found')
def char_read(self, uuid):
"""Read value of given GATT characteristic UUID"""
if uuid.casefold() in self.chars:
return self.chars[uuid.casefold()].ReadValue({})
else:
raise KeyError(f'UUID {uuid} not found')
device_address = '11:22:33:44:55:66'
light_state = '932c32bd-0002-47a2-835a-a8d455b859dd'
dev = Central(device_address )
dev.connect()
dev.char_write(light_state , [1])
sleep(5)
dev.char_write(light_state , [0])
print(dev.char_read(light_state ))
dev.disconnect()
As I don't have a bulb the above is untested. But should be a good outline of what is required.
It worked for me after I reset the Bulb with the bluetooth app to factory settings.
The bulb appears to be able to be paired/bonded to a single device only. If other devices try to communicate with the bulb, the connection is lost, as #ukBaz mentioned in his comment.

Reading data from a Bluetooth device low energy rfcomm python3

Faced a problem. There is a bluetooth device with low power consumption. BLE. The goal is to send a command to the device and get the data back.
For example: command - 0x** 0x** 0x**, where first 0x** - code command, second 0x - data lenght. Response mast be - 0x** 0x** 0x**. I can not send a command to the device. The device works by RFCOMM. Actually the code that is available, but it does not give a result - it says that the device is off.
from bluetooth import *
import socket
class Work:
def __init__(self):
self.rfcon = BluetoothSocket(RFCOMM)
# self.socket = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM)
self.server = '**:**:**:**:**:**'
self.port = 1
self.data = '0x01 0x00 0x00'
def scan_device(self):
connection = self.rfcon.connect((self.server, self.port))
print('con ===>>> ', connection)
senddata = self.rfcon.send(self.data)
print('senddata ====>>>> ', senddata)
data = self.rfcon.recv(256)
if not data:
print("no data!!!")
self.rfcon.close()
else:
print(data)
self.rfcon.close()
if __name__ == '__main__':
a = Work()
a.scan_device()
a.rfcon.close()
I made it through another library - the code:
from bluepy.btle import *
class Work:
def __init__(self):
self.initialize = Peripheral()
def scan_devices(self):
scanner = Scanner()
devices = scanner.scan(10.0)
for dev in devices:
print("Device %s (%s), RSSI=%d dB" % (dev.addr, dev.addrType, dev.rssi))
for (adtype, desc, value) in dev.getScanData():
print(" %s = %s" % (desc, value))
def connect_to_device(self):
print('start con')
connection = self.initialize.connect('**:**:**:**:**:**', 'public')
print('initialize complite')
return connection
def check_device_status(self):
print('test ====>>> ', self.initialize.getCharacteristics())
cmd = '0x01 0x00 0x00 0x20 0x00'.encode('UTF-8')
print(cmd)
status_device = self.initialize.readCharacteristic(cmd)
print('Device status => ', status_device)
def diconnect(self):
self.initialize.disconnect()
if __name__ == '__main__':
a = Work()
a.connect_to_device()
a.check_device_status()
a.diconnect()
It gives a connection but does not send a command and does not return a value since this library does not know what RFCOMM is. Perhaps someone faced this problem in the python and knows how to solve it?
RFCOMM is a protocol of Bluetooth Classic, BLE does not support it. It is impossible to use RFCOMM for communicating with a BLE device.
You should read an introduction to BLE, it will give you a basic understanding of BLE.
Anything further will be guessing, it depends on how the BLE device is configured.
If you are using your own device that you can configure, one possibility is to create a characteristic that supports Write and Indicate. You can indicate (to be notified when the characteristic value changes and what is the new value) and write the command. The response will be received via an indication.
For most practical purposes the answer that RFCOMM is only available in Bluetooth "Classic" is true: most Bluetooth LE devices don't support RFCOMM. However, in principle the Bluetooth Core Spec describes how a channel for RFCOMM can be opened between two LE devices using LE credit-based control flow with an L2CAP_LE_CREDIT_BASED_CONNECTION_REQ command (introduced in Core Spec v4.1 Vol 3 Part A Chapter 4.22 and the Assigned Numbers document).

Python 3.4 - How to 'run' another script python script continuously, How to pass http get / post to socket

This question is two-fold.
1. So I need to run code for a socket server that's all defined and created in another.py, Clicking run on PyCharm works just fine, but if you exec() the file it just runs the bottom part of the code.
There are a few answers here but they are conflicting and for Python 2.
From what I can gather there are three ways:
- Execfile(), Which I think is Python 2 code.
- os.system() (But I've seen it be said that it's not correct to pass to the OS for this)
- And subprocess.Popen (unsure how to use this either)
I need this to run in the background, it is used to create threads for sockets for the recv portion of the overall program and listen on those ports so I can input commands to a router.
This is the complete code in question:
import sys
import socket
import threading
import time
QUIT = False
class ClientThread(threading.Thread): # Class that implements the client threads in this server
def __init__(self, client_sock): # Initialize the object, save the socket that this thread will use.
threading.Thread.__init__(self)
self.client = client_sock
def run(self): # Thread's main loop. Once this function returns, the thread is finished and dies.
global QUIT # Need to declare QUIT as global, since the method can change it
done = False
cmd = self.readline() # Read data from the socket and process it
while not done:
if 'quit' == cmd:
self.writeline('Ok, bye. Server shut down')
QUIT = True
done = True
elif 'bye' == cmd:
self.writeline('Ok, bye. Thread closed')
done = True
else:
self.writeline(self.name)
cmd = self.readline()
self.client.close() # Make sure socket is closed when we're done with it
return
def readline(self): # Helper function, read up to 1024 chars from the socket, and returns them as a string
result = self.client.recv(1024)
if result is not None: # All letters in lower case and without and end of line markers
result = result.strip().lower().decode('ascii')
return result
def writeline(self, text): # Helper func, writes the given string to the socket with and end of line marker at end
self.client.send(text.strip().encode("ascii") + b'\n')
class Server: # Server class. Opens up a socket and listens for incoming connections.
def __init__(self): # Every time a new connection arrives, new thread object is created and
self.sock = None # defers the processing of the connection to it
self.thread_list = []
def run(self): # Server main loop: Creates the server (incoming) socket, listens > creates thread to handle it
all_good = False
try_count = 0 # Attempt to open the socket
while not all_good:
if 3 < try_count: # Tried more than 3 times without success, maybe post is in use by another program
sys.exit(1)
try:
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Create the socket
port = 80
self.sock.bind(('127.0.0.1', port)) # Bind to the interface and port we want to listen on
self.sock.listen(5)
all_good = True
break
except socket.error:
print('Socket connection error... Waiting 10 seconds to retry.')
del self.sock
time.sleep(10)
try_count += 1
print('Server is listening for incoming connections.')
print('Try to connect through the command line with:')
print('telnet localhost 80')
print('and then type whatever you want.')
print()
print("typing 'bye' finishes the thread. but not the server",)
print("eg. you can quit telnet, run it again and get a different ",)
print("thread name")
print("typing 'quit' finishes the server")
try:
while not QUIT:
try:
self.sock.settimeout(0.500)
client = self.sock.accept()[0]
except socket.timeout:
time.sleep(1)
if QUIT:
print('Received quit command. Shutting down...')
break
continue
new_thread = ClientThread(client)
print('Incoming Connection. Started thread ',)
print(new_thread.getName())
self.thread_list.append(new_thread)
new_thread.start()
for thread in self.thread_list:
if not thread.isAlive():
self.thread_list.remove(thread)
thread.join()
except KeyboardInterrupt:
print('Ctrl+C pressed... Shutting Down')
except Exception as err:
print('Exception caught: %s\nClosing...' % err)
for thread in self.thread_list:
thread.join(1.0)
self.sock.close()
if "__main__" == __name__:
server = Server()
server.run()
print('Terminated')
Notes:
This is created in Python 3.4
I use Pycharm as my IDE.
One part of a whole.
2. So I'm creating a lightning detection system and this is how I expect it to be done:
- Listen to the port on the router forever
The above is done, but the issue with this is described in question 1.
- Pull numbers from a text file for sending text message
Completed this also.
- Send http get / post to port on the router
The issue with this is that i'm unsure how the router will act if I send this in binary form, I suspect it wont matter, the input commands for sending over GSM are specific. Some clarification may be needed at some point.
- Recieve reply from router and exception manage
- Listen for relay trip for alarm on severe or close strike warning.
- If tripped, send messages to phones in storage from text file
This would be the http get / post that's sent.
- Wait for reply from router to indicate messages have been sent, exception handle if it's not the case
- Go back to start
There are a few issues I'd like some background knowledge on that is proving hard to find via the old Google and here on the answers in stack.
How do I grab the receive data from the router from another process running in another file? I guess I can write into a text file and call that data but i'd rather not.
How to multi-process and which method to use.
How to send http get / post to socket on router, post needed occording to the router manual is as follows: e.g. "http://192.168.1.1/cgi-bin/sms_send?number=0037061212345&text=test"
Notes: Using Sockets, threading, sys and time on Python 3.4/Pycharm IDE.
Lightning detector used is LD-250 with RLO Relay attached.
RUT500 Teltonica router used.
Any direction/comments, errors spotted, anything i'm drastically missing would be greatly appreciated! Thank you very much in advance :D constructive criticism is greatly encouraged!
Okay so for the first part none of those suggested in the OP were my answer. Running the script as is from os.system(), exec() without declaring a new socket object just ran from __name__, this essentially just printed out "terminated", to get around this was simple. As everything was put into a classes already, all I had to do is create a new thread. This is how it was done:
import Socketthread2
new_thread = Socketthread2.Server() # Effectively declaring a new server class object.
new_thread.run()
This allowed the script to run from the beginning by initialising the code from the start in Socket, which is also a class of Clientthread, so that was also run too. Running this at the start of the parent program allowed this to run in the background, then continue with the new code in parent while the rest of the script was continuously active.

Obtain bluetooth signal strength on Raspberry Pi of BT device without pairing

I like to create a kind of indoor-tracking-system for my already existing home automation system. I thought of using BLE. I already successfully set up hcitool on my Raspberry Pi and I can connect to my iPhone without any problems. But how can I obtain the signal strength between my Raspberry Pi and my iPhone without connecting them. I already tried to use sudo hcitool cc [BTADDRESS] to connect to my iPhone without authentication, but it looks like the iPhone don't allow those connection to stay open. I think that must be a way to get the signal strength without connecting both devices. I want to use it to determine the distance from my Raspberry Pi to my iPhone. May I am able to calculate the distance from the time I need to discover my iPhone?
There are two ways to go, and by now I have been able to get both work reliably only on Android devices.
Exploiting the Bluetooth friendly name of the smartphone and set the discoverability to infinite. I have done this writing a simple app. Works in background, also after that the app has been killed, since the discoverability setting is preserved. At the best of my knowledge, this is not possible in iOS.
Advertising a UUID in a BLE packet from the phone. This can be done by both Android and iOS devices. However, while in background, iPhones switch the advertising to a shrinked mode that makes the packet unidentifiable. The problem of identifying an advertising iOS devices in background is still open.
On the raspberry, I used PyBluez to scan and looking for the presence of smartphones running (1) or (2). I report a code example:
import bluetooth
import bluetooth._bluetooth as bluez
import struct, socket, sys, select
def hci_enable_le_scan(sock):
hci_toggle_le_scan(sock, 0x01)
#Discover name and RSS of enabled BLE devices
class MyDiscoverer(bluetooth.DeviceDiscoverer):
def pre_inquiry(self):
self.done = False
def device_discovered(self, address, device_class, rssi, name):
discovery_logger.info("Discovered %s" % (address, ))
if name == "YOUR-DEVICE-FRIENDLY_NAME":
#Use the RSS for your detection / localization system
def inquiry_complete(self):
self.done = True
#Performs inquiry for name request
def async_inquiry():
d = MyDiscoverer()
while True:
d.find_devices(lookup_names = True)
readfiles = [ d, ]
while True:
rfds = select.select( readfiles, [], [] )[0]
if d in rfds:
d.process_event()
if d.done:
break
time.sleep(DISCOVERY_INTERVAL)
#Parse received advertising packets
def parse_events(sock):
# save current filter
old_filter = sock.getsockopt( bluez.SOL_HCI, bluez.HCI_FILTER, 14)
flt = bluez.hci_filter_new()
bluez.hci_filter_all_events(flt)
bluez.hci_filter_set_ptype(flt, bluez.HCI_EVENT_PKT)
sock.setsockopt( bluez.SOL_HCI, bluez.HCI_FILTER, flt )
while True:
pkt = sock.recv(255)
ptype, event, plen = struct.unpack("BBB", pkt[:3])
if event == LE_META_EVENT:
subevent, = struct.unpack("B", pkt[3])
pkt = pkt[4:]
if subevent == EVT_LE_CONN_COMPLETE:
le_handle_connection_complete(pkt)
elif subevent == EVT_LE_ADVERTISING_REPORT:
#Check if the advertisement is the one we are searching for
if getASCII(pkt[start:end]) == "YOUR-UUID"
report_pkt_offset = 0
report_data_length, = struct.unpack("B", pkt[report_pkt_offset + 9])
# each report is 2 (event type, bdaddr type) + 6 (the address)
# + 1 (data length field) + report_data length + 1 (rssi)
report_pkt_offset = report_pkt_offset + 10 + report_data_length + 1
rssi, = struct.unpack("b", pkt[report_pkt_offset -1])
#Now you have the RSS indicator, use it for monitoring / localization
sock.setsockopt( bluez.SOL_HCI, bluez.HCI_FILTER, old_filter )
dev_id = 0
try:
sock = bluez.hci_open_dev(dev_id)
except:
print "error accessing bluetooth device..."
sys.exit(1)
p = threading.Thread(group=None, target=parse_events, name='parsing', args=(sock, ))
d = threading.Thread(group=None, target=async_inquiry, name='async_inquiry', args=())
try:
p.start()
except:
print "Error: unable to start parsing thread"
try:
d.start()
except:
print "Error: unable to start asynchronous discovery thread"

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