Getting Data from PolarH10 via BLE - python-3.x

I have been trying to get data from my PolarH10 with my raspberry-pi. I have been successfully getting data through the commandline with bluez, but have been unable to reproduce that in python. I am using pygatt(gatttool bindings) and python3.
I have been closely following the examples provided on bitbucket and was able to detect my device and filter out it's MAC address by filtering it by name. I however was unable to get either of the "reading data asyncronously" examples to work.
#This doesnt work...
req = gattlib.GATTRequester(mymac)
response = gattlib.GATTResponse()
req.read_by_handle_async(0x15, response) # what does the 0x15 mean?
while not response.received():
time.sleep(0.1)
steps = response.received()[0]
...
#This doesn't work either
class NotifyYourName(gattlib.GATTResponse):
def on_response(self, data):
print("your data is: {}".format(data))
response = NotifyYourName()
req = gattlib.GATTRequester(mymac)
req.read_by_handle_async(0x15, response)
while True:
# here, do other interesting things
time.sleep(1)
I don't know and cannot extract from the "documentation(s)" how to subscribe to/read notifications from a characteristic(heart rate) of my sensor(PolarH10). The error I am getting is when calling GATTRequester.connect(True) is
RuntimeError: Channel or attrib not ready.
Please tell me how correctly connect to a BLE device via Python on Debian and how to programatically identify offered services and their characteristics and how to get their notifications asyncronously in python using gattlib(pygatt) or any other library. Thanks!

The answer is: Just use bleak.

I have a device that presents the same behavior. In my case, the problem was that it does not have a channel of type public, I should use random instead (like in gatttool -b BE:BA:CA:FE:BA:BE -I -t random).
Just calling the connect() method with the parameter channel_type to random could fix it:
requester.connect(True, channel_type="random")
PD: Sorry for the late response (maybe it will be helpful to others).

Related

Appropriate way to run pytest unit tests for your API using threading.Thread and virtualports with socat

So I have written API for a device. The unit tests are going to run on CI automatically, therefore I will not test the connection with the device, purpose of these unit tests are to just test that my API generate appropriate requests and appropriately react to responses.
Before I had the following:
import serial
import threading
from src.device import Device # that is my API
class TestDevice:
#pytest.fixture(scope='class')
def device(self):
dev = Device()
dev.connect(port='/dev/ttyUSB0')
dev.connect() constantly sends command through serial port to establish handshake it will stay inside the function until response is received or timeout happens
So in order to simulate device, I have opened virtual serial port using socat:
socat -d -d pty,raw,echo=0 pty,raw,echo=0
My idea is to write into one virtual port and read from another. For that I would launch another threading and read from the message that has been sent, and upon thread receiving handshake request, I would sent a reply like this:
class TestDevice:
#pytest.fixture(scope='class')
def device(self):
reader_thread = threading.Thread(target=self.reader)
reader_thread.start()
dev = Device()
dev.connect('/dev/pts/3')
def reader(self):
EXPECTED_HANDSHAKE = b"hello"
HANDSHAKE_REPLY = b"hi"
timeout_handshake_ms = 1000
reader_port = serial.Serial(port='/dev/pts/4', baudrate=115200)
start_time_ns = time.time_ns()
timeout_time_ns = start_time_ns + (timeout_handshake_ms * 1e6)
while time.time_ns() < timeout_time_ns:
response = reader_port.read(1024)
# if dev.connect() sent an appropriate handshake request
# this port would receive it and then
if response == EXPECTED_HANDSHAKE:
reader_port.write(HANDSHAKE_REPLY)
And once the reply is received, dev.connect() will exit successfully and device will be considered successful. All of the code that I have posted works. As you can see, my approach is that I first start reading in a different thread, then I send a command, and in the reader thread I read the response and send appropriate response if applicable. The connection part was an easy one. However, I have 30 commands to test, all of them have different inputs, multiple arguments and etc. Reader's response also varies depending on the Request generated by API. Therefore, I will be needing to send same command with different arguments and I will need to reply to command in many different ways. What is the best way to organize my code, so I can test everything as possible as efficiently as possible. Do I need a thread for every command I am testing? Is there an efficient way to do all of this I have set out to?

zbus connection not displayed in busctl list

I'm using the zbus crate to make a server able to get events from the dbus.
It works well my code (basically the same as the example from the documentation) is able to receive events so it's fine.
I use busctl to send an event like in the example:
busctl --user call org.zbus.MyGreeter /org/zbus/MyGreeter org.zbus.MyGreeter1 SayHello s "Maria"
And my code is able to receive the event with the parameter just fine.
The thing is I'm having some issues with udev and while I was trying to fix it I found some weird things:
If I send an event with another user it fails with Call failed: the name org.zbus.MyGreeter was not provided by any .service files while my program is running
When I do busctl list --acquired I don't see org.zbus.MyGreeter in the result
My question is: is it normal my program does not appear in the busctl list? Am I doing something wrong or do I use the wrong library to do what I want to do?
Ok it seems there are 2 busses and I was not using the system bus.
I had to replace the method session to system to indicates I want my program to run on the system bus.
Like this:
let _ = ConnectionBuilder::system()?
.name("org.zbus.MyGreeter")?
.serve_at("/org/zbus/MyGreeter", greeter)?
.build()
.await?;
Doing this is not enough because my program does not have to permission to create a service on the bus system. So I had to create a file in /usr/share/dbus-1/system.d where I did write the configuration needed.

Communication with Python and Supercollider through OSC

I'm trying to connect Python with Supercollider through OSC, but it's not working.
I'm using Python3 and the library osc4py3.
The original idea was to send a text word by word, but upon trying I realized the connection was not working.
Here's the SC code:
(
OSCdef.new(\texto,{
|msg, time, addr, port|
[msg, time, addr,port].postIn;
},
'/texto/supercollider',
n
)
)
OSCFunc.trace(true);
o = OSCFunc(\texto);
And here's the Python code:
osc_startup()
osc_udp_client("127.0.0.1", 57120, "supercollider")
## here goes a function called leerpalabras to separate words in rows.
with open("partitura.txt", "r") as f:
for palabra in leerpalabras(f):
msg = oscbuildparse.OSCMessage("/texto/supercollider", ",s", palabra)
osc_send(msg, "supercollider")
sleep(2)
osc_terminate()
I've also tried with this, to see if maybe there was something wrong with my for loop (with the startup, and terminate of course):
msg = oscbuildparse.OSCMessage("/texto/supercollider", ",s", "holis")
osc_send(msg, "supercollider")
I run the trace method on SC, nothing appears on the post window when I run the Python script on terminal, but no error appears on neither one of them, so I'm a bit lost on what I can test to make sure is getting somewhere.
It doesn't print on the SC post window, it just says OSCdef(texto, /texto/supercollider, nil, nil, nil).
When I run the SuperCollider piece of your example, and then run:
n = NetAddr("127.0.0.1", 57120);
n.sendMsg('/texto/supercollider', 1, 2, 3);
... I see the message printed immediately (note that you used postIn instead of postln, if you don't fix that you'll get an error instead of a printed message).
Like you, I don't see anything when I send via the Python library - my suspicion is that there's something wrong on the Python side? There's a hint in this response that you have to call osc_process() after sends, but that still doesn't work for me
You can try three things:
Run OSCFunc.trace in SuperCollider and watch for messages (this will print ALL incoming OSC messages), to see if your OSCdef is somehow not receiving messages.
Try a network analyzer like Packet Peeper (http://packetpeeper.org/) to watch network traffic on your local loopback network lo0. When I do this, I can clearly see messages sent by SuperCollider, but I don't see any of the messages I send from Python, even when I send in a loop and call osc_process().
If you can't find any sign of Python sending OSC packets, try a different Python library - there are many others available.
(I'm osc4py3 author)
osc4py3 store messages to send within internal lists and returns immediately. These lists are processed during osc_process() calls or directly by background threads (upon selected theading model).
So, if you have selected as_eventloop threading model, you need to call osc_process() some times, like:
…
with open("partitura.txt", "r") as f:
for palabra in leerpalabras(f):
msg = oscbuildparse.OSCMessage("/texto/supercollider", ",s", palabra)
osc_send(msg, "supercollider")
for missme in range(4):
osc_process()
sleep(0.5)
…
See doc: https://osc4py3.readthedocs.io/en/latest/userdoc.html#threading-model

Bluetoothctl or gatttool for BLE notifications from multiple devices

I have read many questions on the topic but found no information on how to best (or if it is even possible) to receive notifications from more than 1 device at a time using any library or API (preferably command line or Python library).
After connecting to different devices e.g. Heart Rate monitor and Phone, or two HR monitors, is there a way to receive data from 1 service from each device at the same time?
EDIT:
I have managed to connect different devices of the same characteristics and been able to get notifications from them using Bluetoothctl (part of Bluez) so long as I don't request the same service, which answers my question partially; still, does anyone know of a better way to do this?
1) First of all there is a github python project that does just that in Linux on Raspberry Pi: https://github.com/IanHarvey/bluepy
2) Second this snipet from Anthony Chiu uses that API to communicate with multiple devices using notifications:
from bluepy.btle import Scanner, DefaultDelegate, Peripheral
import threading
class NotificationDelegate(DefaultDelegate):
def __init__(self, number):
DefaultDelegate.__init__(self)
self.number = number
def handleNotification(self, cHandle, data):
print 'Notification:\nConnection:'+str(self.number)+ \nHandler:'+str(cHandle)+'\nMsg:'+data
bt_addrs = ['00:15:83:00:45:98', '00:15:83:00:86:72']
connections = []
connection_threads = []
scanner = Scanner(0)
class ConnectionHandlerThread (threading.Thread):
def __init__(self, connection_index):
threading.Thread.__init__(self)
self.connection_index = connection_index
def run(self):
connection = connections[self.connection_index]
connection.setDelegate(NotificationDelegate(self.connection_index))
while True:
if connection.waitForNotifications(1):
connection.writeCharacteristic(37, 'Thank you for the notification!')
while True:
print'Connected: '+str(len(connection_threads))
print 'Scanning...'
devices = scanner.scan(2)
for d in devices:
print(d.addr)
if d.addr in bt_addrs:
p = Peripheral(d)
connections.append(p)
t = ConnectionHandlerThread(len(connections)-1)
t.start()
connection_threads.append(t)
3) I will just write the manual connection option with bluetoothctl that you probably tried. Since it wasn't listed here, I will add that too:
**Manual connection with bluetoothctl: ** To get the list of characteristics you can use the “list-attributes” command after establing connection and entering Generic Attribute Submenu through menu gatt in bluetoothctl, which should print the same list as above:
list-attributes 00:61:61:15:8D:60
To read an attribute you first select it, with the -you guessed it- “select-attribute” command:
select-attribute /org/bluez/hci0/dev_00_61_61_15_8D_60/service000a/char000b
After that you can issue the “read” command, without any parameters.
To read a characteristic continuously (if characteristic supports it) , use the “notify” command:
notify on
PS: This is my first answer on stackoverflow :)
I am also new to BLE, so bear with me. Am interested in your project, any links / contact are appreciated :)
You can find me on alexandrudancu.com

receive SMS using python and python-smpp

I'm a newbie in SMPP but I need to simulate traffic over the SMPP protocol. I have found the tutorial how to send SMS using smpp lib from Python How to Send SMS using SMPP Protocol
I'm trying to write a receiver,but I am unable to get it to work. Please help.
My code is:
import smpplib
class ClientCl():
client=None
def receive_SMS(self):
client=smpplib.client.Client('localhost',1000)
try:
client.connect()
client.bind_receiver("sysID","login","password")
sms=client.get_message()
print(sms)
except :
print("boom! nothing works")
pass
sms_getter=ClientCl.receive_SMS
From what I can understand the smpplib you are using is the one available at github. Looking at your code and the client code, I can't find the function client.get_message. Perhaps you have an older version of the library? Or I have the wrong library. In any case, it is likely that the get_message function does not block and wait for the message to arrive.
Looking at the client code it seems that you have two options:
Poll the library until you get a valid message
Setup the library to listen to the SMPP port and call a function once a message arrives.
If you look at the README.md file it shows how you can setup the library to implement the second option (which is the better option).
...
client = smpplib.client.Client('example.com', SOMEPORTNUMBER)
# Print when obtain message_id
client.set_message_sent_handler(
lambda pdu: sys.stdout.write('sent {} {}\n'.format(pdu.sequence, pdu.message_id)))
client.set_message_received_handler(
lambda pdu: sys.stdout.write('delivered {}\n'.format(pdu.receipted_message_id)))
client.connect()
client.bind_transceiver(system_id='login', password='secret')
for part in parts:
pdu = client.send_message(
source_addr_ton=smpplib.consts.SMPP_TON_INTL,
#source_addr_npi=smpplib.consts.SMPP_NPI_ISDN,
# Make sure it is a byte string, not unicode:
source_addr='SENDERPHONENUM',
dest_addr_ton=smpplib.consts.SMPP_TON_INTL,
#dest_addr_npi=smpplib.consts.SMPP_NPI_ISDN,
# Make sure thease two params are byte strings, not unicode:
destination_addr='PHONENUMBER',
short_message=part,
data_coding=encoding_flag,
esm_class=msg_type_flag,
registered_delivery=True,
)
print(pdu.sequence)
client.listen()
...
When receiving a message or delivery receipt the function defined in client.set_message_received_handler() will be called. In the example, it is a lambda function. There is also an example on how to set up for listening in a thread.
If you prefer the simpler polling option you should use the poll function. For the simplest implementation all you need to do is:
while True:
client.Poll()
As before, the function set in client.set_message_received_handler() will be called once a message arrives.

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