bleak icon indicating copy to clipboard operation
bleak copied to clipboard

Published 20 hours ago • verified publisher icon hbldh

Unable to write/notify on mac M1

Open arpa03 opened this issue 2 years ago • 9 comments

  • bleak version: 0.14.3
  • Python version: 3.10.4
  • Operating System: macOS Montery Version 12.4
  • BlueZ version (bluetoothctl -v) in case of Linux: /

Description

I recently switched to a macbook pro with an Apple M1 Pro and have been having problems with Bleak ever since:

  • impossible to notify to a characteristic
  • Impossible to write on a characteristic
  • I don't feel like I have any problems reading

What I Did

I work with a sensorTag. So I tried the script in the examples. And the test made at the end of the code confirms that it is impossible to write a value in a characteristic.

To be sure that the problem does not come from the sensorTag, I ran the same example on a raspberry pi and everything works. (The python version on the raspberry is 3.9.2.)

Here are the logs of the execution of the sensortag.py example on my mac:

2022-06-02 12:56:40,594 bleak.backends.corebluetooth.client DEBUG: Retrieving services...
2022-06-02 12:56:40,649 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverServices_
2022-06-02 12:56:40,650 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Services discovered
2022-06-02 12:56:40,650 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service 180A
2022-06-02 12:56:40,651 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-02 12:56:40,651 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-02 12:56:40,651 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A23
2022-06-02 12:56:40,651 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,652 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 10
2022-06-02 12:56:40,652 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A24
2022-06-02 12:56:40,652 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,652 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 12
2022-06-02 12:56:40,653 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A25
2022-06-02 12:56:40,653 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,653 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 14
2022-06-02 12:56:40,653 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A26
2022-06-02 12:56:40,653 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,653 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 16
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A27
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 18
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A28
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 20
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A29
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,654 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 22
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A2A
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 24
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A50
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 26
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service 180F
2022-06-02 12:56:40,655 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-02 12:56:40,656 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-02 12:56:40,656 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A19
2022-06-02 12:56:40,656 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,656 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 29
2022-06-02 12:56:40,657 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service F000AA00-0451-4000-B000-000000000000
2022-06-02 12:56:40,657 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-02 12:56:40,657 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-02 12:56:40,657 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA01-0451-4000-B000-000000000000
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 35
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA02-0451-4000-B000-000000000000
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 38
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA03-0451-4000-B000-000000000000
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,658 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 40
2022-06-02 12:56:40,659 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service F000AA20-0451-4000-B000-000000000000
2022-06-02 12:56:40,659 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-02 12:56:40,659 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-02 12:56:40,659 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA21-0451-4000-B000-000000000000
2022-06-02 12:56:40,659 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,659 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 43
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA22-0451-4000-B000-000000000000
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 46
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA23-0451-4000-B000-000000000000
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 48
2022-06-02 12:56:40,660 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service F000AA40-0451-4000-B000-000000000000
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA41-0451-4000-B000-000000000000
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 51
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA42-0451-4000-B000-000000000000
2022-06-02 12:56:40,661 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,662 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 54
2022-06-02 12:56:40,662 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA44-0451-4000-B000-000000000000
2022-06-02 12:56:40,662 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-02 12:56:40,662 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 56
2022-06-02 12:56:40,662 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service F000AA80-0451-4000-B000-000000000000
2022-06-02 12:56:40,662 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
<same kind of logs for the other features>
2022-06-02 12:56:40,673 bleak.backends.corebluetooth.client DEBUG: Services resolved for BleakClientCoreBluetooth (07BEE54B-BC31-4D7E-00C6-F5F390589F4D)
Connected: True
2022-06-02 12:56:40,708 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,708 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,708 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a23-0000-1000-8000-00805f9b34fb : bytearray(b'\x86\x9aq\x00\x00\x84\xbe\xc4')

2022-06-02 12:56:40,737 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,737 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,737 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a24-0000-1000-8000-00805f9b34fb : bytearray(b'CC2650 SensorTag')
Model Number: CC2650 SensorTag
2022-06-02 12:56:40,769 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,769 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,769 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a29-0000-1000-8000-00805f9b34fb : bytearray(b'Texas Instruments')
Manufacturer Name: Texas Instruments
2022-06-02 12:56:40,814 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,814 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,814 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a26-0000-1000-8000-00805f9b34fb : bytearray(b'1.50 (Dec  1 2021)')

2022-06-02 12:56:40,842 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,842 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,842 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a27-0000-1000-8000-00805f9b34fb : bytearray(b'N.A.')
Hardware Revision: N.A.
2022-06-02 12:56:40,873 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,873 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,874 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a28-0000-1000-8000-00805f9b34fb : bytearray(b'N.A.')
Software Revision: N.A.
2022-06-02 12:56:40,904 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,904 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,904 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a19-0000-1000-8000-00805f9b34fb : bytearray(b'S')
Battery Level: 83%
2022-06-02 12:56:40,933 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,933 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,934 bleak.backends.corebluetooth.client DEBUG: Read Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\x7f')
I/O Data Pre-Write Value: bytearray(b'\x7f')
2022-06-02 12:56:40,934 bleak.backends.corebluetooth.client DEBUG: Write Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\xa0')
2022-06-02 12:56:40,963 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-02 12:56:40,963 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-02 12:56:40,963 bleak.backends.corebluetooth.client DEBUG: Read Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\x7f')
I/O Data Post-Write Value: bytearray(b'\x7f')
2022-06-02 12:56:40,963 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDisconnectPeripheral_error_
2022-06-02 12:56:40,963 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Peripheral Device disconnected!
Traceback (most recent call last):
  File "path/to/bleak-repo/bleak/examples/sensortag.py", line 154, in <module>
    asyncio.run(main(sys.argv[1] if len(sys.argv) == 2 else ADDRESS))
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/base_events.py", line 646, in run_until_complete
    return future.result()
  File "path/to/bleak-repo/bleak/examples/sensortag.py", line 146, in main
    assert value == write_value
AssertionError```

arpa03 avatar Jun 02 '22 11:06 arpa03

From the logs, we can see that writing and reading in Bleak are working. I'm not familiar with this device, so I'm not sure if the value read from this characteristic is always supposed to match the value written or not.

dlech avatar Jun 02 '22 15:06 dlech

From the logs, we can see that writing and reading in Bleak are working. I'm not familiar with this device, so I'm not sure if the value read from this characteristic is always supposed to match the value written or not.

what is the meaning of error lines like this one ? 2022-06-02 12:56:40,933 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_

According to the documentation, the value read from this characteristic is supposed to match the value written

arpa03 avatar Jun 02 '22 16:06 arpa03

error is just part of the name of the method. (It is the python binding for this.) As noted in the link, this callback is called when the characteristic is read or when a notification is received.

Maybe adding response=True to the args of write_gatt_char() will make a difference? The default is to not wait for a response, so maybe the read happens before the write is complete?

dlech avatar Jun 02 '22 16:06 dlech

I did some tests with the sensortag.py example and the application I'm working on which uses bleak.

On raspberry pi no problem. But on my mac, I used the packetLogger application and I notice that no packet is sent for writing when response=False. On the other hand when response=True the example and my application works (i.e. the packet to write a data is sent).

There is no problem for reading on my mac and on the raspberry pi.

arpa03 avatar Jun 07 '22 13:06 arpa03

But on my mac, I used the packetLogger application and I notice that no packet is sent for writing when response=False.

Interesting... in CoreBluetooth, there is a canSendWriteWithoutResponse API that we haven't made use of so far. I wonder if it returns false in your case and that is why the packet is not sent.

Could you try making the change below to your local install of Bleak on your Mac to see if this is the case?

diff --git a/bleak/backends/corebluetooth/client.py b/bleak/backends/corebluetooth/client.py
index 4431a37..aa9a84c 100644
--- a/bleak/backends/corebluetooth/client.py
+++ b/bleak/backends/corebluetooth/client.py
@@ -315,6 +315,9 @@ class BleakClientCoreBluetooth(BaseBleakClient):
         if not characteristic:
             raise BleakError("Characteristic {} was not found!".format(char_specifier))
 
+        if not self._delegate.peripheral.canSendWriteWithoutResponse():
+            raise RuntimeError("just as we suspected")
+
         value = NSData.alloc().initWithBytes_length_(data, len(data))
         await self._delegate.write_characteristic(
             characteristic.obj,

dlech avatar Jun 07 '22 15:06 dlech

So I added this test and the exception is not launched. (I also displayed the value of self._delegate.peripheral.canSendWriteWithoutResponse() and it is True.

To be sure of my manipulations and to bring more information, here are the commands that I made followed by the packet capture in the case of response=False and response=True:

sensortag.py with response=False

1. console

$ cd bleak
$ git pull
Already up to date.
$ git diff
diff --git a/bleak/backends/corebluetooth/client.py b/bleak/backends/corebluetooth/client.py
index 4431a37..aa9a84c 100644
--- a/bleak/backends/corebluetooth/client.py
+++ b/bleak/backends/corebluetooth/client.py
@@ -315,6 +315,9 @@ class BleakClientCoreBluetooth(BaseBleakClient):
         if not characteristic:
             raise BleakError("Characteristic {} was not found!".format(char_specifier))
 
+        if not self._delegate.peripheral.canSendWriteWithoutResponse():
+            raise RuntimeError("just as we suspected")
+
         value = NSData.alloc().initWithBytes_length_(data, len(data))
         await self._delegate.write_characteristic(
             characteristic.obj,
$ pew mktmpenv
created virtual environment CPython3.10.4.final.0-64 in 184ms
This is a temporary environment. It will be deleted when you exit
$ pip install .
$ pip freeze | grep bleak
bleak @ file:///path/to/bleak/repo
$ cd example
$ python sensortag.py <DEVICE_ADDR>
python sensortag.py <DEVICE_ADDR>
2022-06-08 09:35:28,551 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManagerDidUpdateState_
2022-06-08 09:35:28,551 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Bluetooth powered on
2022-06-08 09:35:28,552 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: 'isScanning' changed
2022-06-08 09:35:28,584 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDiscoverPeripheral_advertisementData_RSSI_
2022-06-08 09:35:28,584 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDiscoverPeripheral_advertisementData_RSSI_
2022-06-08 09:35:28,584 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Discovered device <ADDR>: None @ RSSI: -75 (kCBAdvData <nsdict_keys(['kCBAdvDataIsConnectable', 'kCBAdvDataTimestamp', 'kCBAdvDataManufacturerData', 'kCBAdvDataRxSecondaryPHY', 'kCBAdvDataTxPowerLevel', 'kCBAdvDataRxPrimaryPHY'])>) and Central: <CBCentralManager: 0x600001cd0400>
2022-06-08 09:35:28,584 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Discovered device <ADDR>: None @ RSSI: -75 (kCBAdvData <nsdict_keys(['kCBAdvDataIsConnectable', 'kCBAdvDataTimestamp', 'kCBAdvDataManufacturerData', 'kCBAdvDataRxSecondaryPHY', 'kCBAdvDataTxPowerLevel', 'kCBAdvDataRxPrimaryPHY'])>) and Central: <CBCentralManager: 0x600001cd0400>
2022-06-08 09:35:28,595 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDiscoverPeripheral_advertisementData_RSSI_
2022-06-08 09:35:28,596 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Discovered device <ADDR>: 310 @ RSSI: -94 (kCBAdvData <nsdict_keys(['kCBAdvDataManufacturerData', 'kCBAdvDataTimestamp', 'kCBAdvDataIsConnectable', 'kCBAdvDataRxPrimaryPHY', 'kCBAdvDataRxSecondaryPHY', 'kCBAdvDataLocalName', 'kCBAdvDataServiceUUIDs'])>) and Central: <CBCentralManager: 0x600001cd0400>
2022-06-08 09:35:28,900 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDiscoverPeripheral_advertisementData_RSSI_
2022-06-08 09:35:28,904 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Discovered device <ADDR>: 310 @ RSSI: -98 (kCBAdvData <nsdict_keys(['kCBAdvDataManufacturerData', 'kCBAdvDataTimestamp', 'kCBAdvDataIsConnectable', 'kCBAdvDataRxPrimaryPHY', 'kCBAdvDataRxSecondaryPHY', 'kCBAdvDataLocalName', 'kCBAdvDataServiceUUIDs'])>) and Central: <CBCentralManager: 0x600001cd0400>
2022-06-08 09:35:29,491 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDiscoverPeripheral_advertisementData_RSSI_
2022-06-08 09:35:29,492 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDiscoverPeripheral_advertisementData_RSSI_
2022-06-08 09:35:29,493 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Discovered device <DEVICE_ADDR>: CC2650 SensorTag @ RSSI: -47 (kCBAdvData <nsdict_keys(['kCBAdvDataManufacturerData', 'kCBAdvDataTimestamp', 'kCBAdvDataIsConnectable', 'kCBAdvDataRxPrimaryPHY', 'kCBAdvDataRxSecondaryPHY', 'kCBAdvDataLocalName', 'kCBAdvDataTxPowerLevel', 'kCBAdvDataServiceUUIDs'])>) and Central: <CBCentralManager: 0x600001cd0400>
2022-06-08 09:35:29,494 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Discovered device <DEVICE_ADDR>: CC2650 SensorTag @ RSSI: -47 (kCBAdvData <nsdict_keys(['kCBAdvDataManufacturerData', 'kCBAdvDataTimestamp', 'kCBAdvDataIsConnectable', 'kCBAdvDataRxPrimaryPHY', 'kCBAdvDataRxSecondaryPHY', 'kCBAdvDataLocalName', 'kCBAdvDataTxPowerLevel', 'kCBAdvDataServiceUUIDs'])>) and Central: <CBCentralManager: 0x600001cd0400>
2022-06-08 09:35:29,494 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: 'isScanning' changed
2022-06-08 09:35:29,495 bleak.backends.corebluetooth.client DEBUG: CentralManagerDelegate  at <CentralManagerDelegate: 0x126726c50>
2022-06-08 09:35:29,495 bleak.backends.corebluetooth.client DEBUG: Connecting to BLE device @ <DEVICE_ADDR>
2022-06-08 09:35:29,676 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didConnectPeripheral_
2022-06-08 09:35:29,682 bleak.backends.corebluetooth.client DEBUG: Retrieving services...
2022-06-08 09:35:29,730 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverServices_
2022-06-08 09:35:29,731 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Services discovered
2022-06-08 09:35:29,731 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service 180A
2022-06-08 09:35:29,732 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-08 09:35:29,732 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-08 09:35:29,732 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic 2A23
2022-06-08 09:35:29,732 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-08 09:35:29,733 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 10
...
2022-06-08 09:35:29,738 bleak.backends.corebluetooth.client DEBUG: Retrieving characteristics for service F000AA00-0451-4000-B000-000000000000
2022-06-08 09:35:29,739 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverCharacteristicsForService_error_
2022-06-08 09:35:29,739 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Characteristics discovered
2022-06-08 09:35:29,739 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000AA01-0451-4000-B000-000000000000
2022-06-08 09:35:29,740 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-08 09:35:29,740 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 35
...
2022-06-08 09:35:29,758 bleak.backends.corebluetooth.client DEBUG: Retrieving descriptors for characteristic F000FFC4-0451-4000-B000-000000000000
2022-06-08 09:35:29,759 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didDiscoverDescriptorsForCharacteristic_error_
2022-06-08 09:35:29,759 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Descriptor discovered 111
2022-06-08 09:35:29,759 bleak.backends.corebluetooth.client DEBUG: Services resolved for BleakClientCoreBluetooth (<DEVICE_ADDR>)
Connected: True
2022-06-08 09:35:29,790 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,790 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,790 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a23-0000-1000-8000-00805f9b34fb : bytearray(b'\x86\x9aq\x00\x00\x84\xbe\xc4')
System ID: <DEVICE_ID>
2022-06-08 09:35:29,820 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,820 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,820 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a24-0000-1000-8000-00805f9b34fb : bytearray(b'CC2650 SensorTag')
Model Number: CC2650 SensorTag
2022-06-08 09:35:29,850 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,850 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,850 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a29-0000-1000-8000-00805f9b34fb : bytearray(b'Texas Instruments')
Manufacturer Name: Texas Instruments
2022-06-08 09:35:29,880 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,880 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,880 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a26-0000-1000-8000-00805f9b34fb : bytearray(b'1.50 (Dec  1 2021)')
Firmware Revision: 1.50 (Dec  1 2021)
2022-06-08 09:35:29,910 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,911 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,911 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a27-0000-1000-8000-00805f9b34fb : bytearray(b'N.A.')
Hardware Revision: N.A.
2022-06-08 09:35:29,939 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,940 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,940 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a28-0000-1000-8000-00805f9b34fb : bytearray(b'N.A.')
Software Revision: N.A.
2022-06-08 09:35:29,970 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:29,971 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:29,971 bleak.backends.corebluetooth.client DEBUG: Read Characteristic 00002a19-0000-1000-8000-00805f9b34fb : bytearray(b'V')
Battery Level: 86%
2022-06-08 09:35:30,000 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:30,000 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:30,000 bleak.backends.corebluetooth.client DEBUG: Read Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\x7f')
I/O Data Pre-Write Value: bytearray(b'\x7f')
2022-06-08 09:35:30,001 bleak.backends.corebluetooth.client DEBUG: Write Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\xa0')
2022-06-08 09:35:30,030 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:35:30,031 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:35:30,031 bleak.backends.corebluetooth.client DEBUG: Read Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\x7f')
I/O Data Post-Write Value: bytearray(b'\x7f')
2022-06-08 09:35:30,032 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDisconnectPeripheral_error_
2022-06-08 09:35:30,032 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Peripheral Device disconnected!
Traceback (most recent call last):
  File "path/to/bleak/examples/sensortag.py", line 154, in <module>
    asyncio.run(main(sys.argv[1] if len(sys.argv) == 2 else ADDRESS))
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/base_events.py", line 646, in run_until_complete
    return future.result()
  File "path/to/bleak/examples/sensortag.py", line 146, in main
    assert value == write_value
AssertionError

2. packet capture

Jun 08 09:35:29.453  HCI Event        0x0000  <SENSORTAG_ADDR>  LE - Advertising Report - 1 Report - Normal - Public - <SENSORTAG_ADDR> - ADV_IND  -47 dBm - Manufacturer Specific Data - Channel 37  
Jun 08 09:35:29.454  HCI Event        0x0000  <SENSORTAG_ADDR>  LE - Advertising Report - 1 Report - Normal - Public - <SENSORTAG_ADDR> - SCAN_RSP  -47 dBm - CC2650 SensorTag - Channel 37  
Jun 08 09:35:29.464  HCI Command      0x0000  <SENSORTAG_ADDR>  LE Add Device To Filter Accept List - Public - <SENSORTAG_ADDR>  
Jun 08 09:35:29.554  HCI Event        0x0000  <SENSORTAG_ADDR>  LE - Advertising Report - 1 Report - Normal - Public - <SENSORTAG_ADDR> - ADV_IND  -48 dBm - Manufacturer Specific Data - Channel 39  
Jun 08 09:35:29.555  HCI Event        0x005D  <SENSORTAG_ADDR>  LE - Enhanced Connection Complete - Central - Public - <SENSORTAG_ADDR> local - 00:00:00:00:00:00 peer - 00:00:00:00:00:00 - Conn Interval: 15 ms  
Jun 08 09:35:29.558  HCI Command      0x0000  <SENSORTAG_ADDR>  LE Remove Device From Filter Accept List - Public - <SENSORTAG_ADDR>  
Jun 08 09:35:29.568  HCI Command      0x005D  <SENSORTAG_ADDR>  Read Remote Version Information - Connection Handle: 0x005D  
Jun 08 09:35:29.604  HCI Event        0x005D  <SENSORTAG_ADDR>  Read Remote Version Information Complete  
Jun 08 09:35:29.604  HCI Command      0x005D  <SENSORTAG_ADDR>  LE Read Remote Used Features - Connection Handle: 0x005D  
Jun 08 09:35:29.635  HCI Event        0x005D  <SENSORTAG_ADDR>  LE - Read Remote Used Features Complete - DPLE Unsupported  
Jun 08 09:35:29.637  ATT Send         0x005D  <SENSORTAG_ADDR>  Exchange MTU Request - MTU: 185  
Jun 08 09:35:29.665  ATT Receive      0x005D  <SENSORTAG_ADDR>  Exchange MTU Response - MTU: 23  
Jun 08 09:35:29.665  ATT Send         0x005D  <SENSORTAG_ADDR>  Read By Type Request - Start Handle: 0x0008 - End Handle: 0x0008 - UUID: GATT Characteristic Declaration  
Jun 08 09:35:29.695  ATT Receive      0x005D  <SENSORTAG_ADDR>  Error Response - Attribute Handle: 0x0008 - Error Code: Attribute Not Found (0x0A)  
Jun 08 09:35:29.725  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x000B  
Jun 08 09:35:29.728  HCI Event        0x005D  <SENSORTAG_ADDR>  Number Of Completed Packets - Handle: 0x005D - Packets: 0x0002    
Jun 08 09:35:29.755  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 869A 7100 0084 BEC4  
Jun 08 09:35:29.756  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x000D  
Jun 08 09:35:29.785  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 4343 3236 3530 2053 656E 736F 7254 6167  
Jun 08 09:35:29.786  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x0017  
Jun 08 09:35:29.789  HCI Event        0x005D  <SENSORTAG_ADDR>  Number Of Completed Packets - Handle: 0x005D - Packets: 0x0002    
Jun 08 09:35:29.815  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 5465 7861 7320 496E 7374 7275 6D65 6E74…  
Jun 08 09:35:29.816  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x0011  
Jun 08 09:35:29.845  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 312E 3530 2028 4465 6320 2031 2032 3032…  
Jun 08 09:35:29.846  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x0013  
Jun 08 09:35:29.849  HCI Event        0x005D  <SENSORTAG_ADDR>  Number Of Completed Packets - Handle: 0x005D - Packets: 0x0002    
Jun 08 09:35:29.875  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 4E2E 412E  
Jun 08 09:35:29.877  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x0015  
Jun 08 09:35:29.905  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 4E2E 412E  
Jun 08 09:35:29.906  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x001E  
Jun 08 09:35:29.907  HCI Event        0x005D  <SENSORTAG_ADDR>  Number Of Completed Packets - Handle: 0x005D - Packets: 0x0002    
Jun 08 09:35:29.935  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 56  
Jun 08 09:35:29.937  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x0051  
Jun 08 09:35:29.965  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 7F  
Jun 08 09:35:29.967  ATT Send         0x005D  <SENSORTAG_ADDR>  Read Request - Handle:0x0051  
Jun 08 09:35:29.970  HCI Event        0x005D  <SENSORTAG_ADDR>  Number Of Completed Packets - Handle: 0x005D - Packets: 0x0002    
Jun 08 09:35:29.995  ATT Receive      0x005D  <SENSORTAG_ADDR>  Read Response - Value: 7F  
Jun 08 09:35:29.998  HCI Command      0x005D  <SENSORTAG_ADDR>  Disconnect - Connection Handle: 0x005D - Reason: Remote User Terminated Connection  
Jun 08 09:35:30.010  HCI Event        0x005D  <SENSORTAG_ADDR>  Disconnection Complete - Success

sensortag.py with response=False

1. console

diff --git a/examples/sensortag.py b/examples/sensortag.py
index 86047aa..d6baa60 100644
--- a/examples/sensortag.py
+++ b/examples/sensortag.py
@@ -139,7 +139,7 @@ async def main(address):
         value = await client.read_gatt_char(IO_DATA_CHAR_UUID)
         print("I/O Data Pre-Write Value: {0}".format(value))
 
-        await client.write_gatt_char(IO_DATA_CHAR_UUID, write_value)
+        await client.write_gatt_char(IO_DATA_CHAR_UUID, write_value, response=True)
 
         value = await client.read_gatt_char(IO_DATA_CHAR_UUID)
         print("I/O Data Post-Write Value: {0}".format(value))
$ python sensortag.py <DEVICE_ADDR>

.....
Battery Level: 86%
2022-06-08 09:43:53,854 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:43:53,855 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:43:53,855 bleak.backends.corebluetooth.client DEBUG: Read Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\x7f')
I/O Data Pre-Write Value: bytearray(b'\x7f')
2022-06-08 09:43:53,884 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didWriteValueForCharacteristic_error_
2022-06-08 09:43:53,884 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Write Characteristic Value
2022-06-08 09:43:53,884 bleak.backends.corebluetooth.client DEBUG: Write Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\xa0')
2022-06-08 09:43:53,914 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateValueForCharacteristic_error_
2022-06-08 09:43:53,915 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Read characteristic value
2022-06-08 09:43:53,915 bleak.backends.corebluetooth.client DEBUG: Read Characteristic f000aa65-0451-4000-b000-000000000000 : bytearray(b'\xa0')
I/O Data Post-Write Value: bytearray(b'\xa0')
2022-06-08 09:43:53,944 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateNotificationStateForCharacteristic_error_
2022-06-08 09:43:53,944 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Character Notify Update
2022-06-08 09:43:58,984 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: peripheral_didUpdateNotificationStateForCharacteristic_error_
2022-06-08 09:43:58,986 bleak.backends.corebluetooth.PeripheralDelegate DEBUG: Character Notify Update
2022-06-08 09:43:58,988 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: centralManager_didDisconnectPeripheral_error_
2022-06-08 09:43:58,988 bleak.backends.corebluetooth.CentralManagerDelegate DEBUG: Peripheral Device disconnected!

2. packet capture

Jun 08 09:43:53.305  HCI Event        0x0000  <DEVICE_ADDR>  LE - Advertising Report - 1 Report - Normal - Public - <DEVICE_ADDR> - ADV_IND  -45 dBm - Manufacturer Specific Data - Channel 37  
Jun 08 09:43:53.305  HCI Event        0x0000  <DEVICE_ADDR>  LE - Advertising Report - 1 Report - Normal - Public - <DEVICE_ADDR> - SCAN_RSP  -45 dBm - CC2650 SensorTag - Channel 37  
Jun 08 09:43:53.319  HCI Command      0x0000  <DEVICE_ADDR>  LE Add Device To Filter Accept List - Public - <DEVICE_ADDR>  
Jun 08 09:43:53.415  HCI Event        0x0000  <DEVICE_ADDR>  LE - Advertising Report - 1 Report - Normal - Public - <DEVICE_ADDR> - ADV_IND  -44 dBm - Manufacturer Specific Data - Channel 40  
Jun 08 09:43:53.416  HCI Event        0x005E  <DEVICE_ADDR>  LE - Enhanced Connection Complete - Central - Public - <DEVICE_ADDR> local - 00:00:00:00:00:00 peer - 00:00:00:00:00:00 - Conn Interval: 15 ms  
Jun 08 09:43:53.419  HCI Command      0x0000  <DEVICE_ADDR>  LE Remove Device From Filter Accept List - Public - <DEVICE_ADDR>  
Jun 08 09:43:53.430  HCI Command      0x005E  <DEVICE_ADDR>  Read Remote Version Information - Connection Handle: 0x005E  
Jun 08 09:43:53.460  HCI Event        0x005E  <DEVICE_ADDR>  Read Remote Version Information Complete  
Jun 08 09:43:53.460  HCI Command      0x005E  <DEVICE_ADDR>  LE Read Remote Used Features - Connection Handle: 0x005E  
Jun 08 09:43:53.489  HCI Event        0x005E  <DEVICE_ADDR>  LE - Read Remote Used Features Complete - DPLE Unsupported  
Jun 08 09:43:53.491  ATT Send         0x005E  <DEVICE_ADDR>  Exchange MTU Request - MTU: 185  
Jun 08 09:43:53.519  ATT Receive      0x005E  <DEVICE_ADDR>  Exchange MTU Response - MTU: 23  
Jun 08 09:43:53.520  ATT Send         0x005E  <DEVICE_ADDR>  Read By Type Request - Start Handle: 0x0008 - End Handle: 0x0008 - UUID: GATT Characteristic Declaration  
Jun 08 09:43:53.549  ATT Receive      0x005E  <DEVICE_ADDR>  Error Response - Attribute Handle: 0x0008 - Error Code: Attribute Not Found (0x0A)  
Jun 08 09:43:53.585  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x000B  
Jun 08 09:43:53.588  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0002    
Jun 08 09:43:53.610  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 869A 7100 0084 BEC4  
Jun 08 09:43:53.611  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x000D  
Jun 08 09:43:53.640  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 4343 3236 3530 2053 656E 736F 7254 6167  
Jun 08 09:43:53.641  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x0017  
Jun 08 09:43:53.642  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0002    
Jun 08 09:43:53.669  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 5465 7861 7320 496E 7374 7275 6D65 6E74…  
Jun 08 09:43:53.671  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x0011  
Jun 08 09:43:53.699  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 312E 3530 2028 4465 6320 2031 2032 3032…  
Jun 08 09:43:53.701  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x0013  
Jun 08 09:43:53.704  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0002    
Jun 08 09:43:53.730  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 4E2E 412E  
Jun 08 09:43:53.731  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x0015  
Jun 08 09:43:53.759  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 4E2E 412E  
Jun 08 09:43:53.760  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x001E  
Jun 08 09:43:53.763  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0002    
Jun 08 09:43:53.789  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 56  
Jun 08 09:43:53.793  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x0051  
Jun 08 09:43:53.819  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: 7F  
Jun 08 09:43:53.821  ATT Send         0x005E  <DEVICE_ADDR>  Write Request - Handle:0x0051 - Value: A0  
Jun 08 09:43:53.824  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0002    
Jun 08 09:43:53.849  ATT Receive      0x005E  <DEVICE_ADDR>  Write Response  
Jun 08 09:43:53.850  ATT Send         0x005E  <DEVICE_ADDR>  Read Request - Handle:0x0051  
Jun 08 09:43:53.879  ATT Receive      0x005E  <DEVICE_ADDR>  Read Response - Value: A0  
Jun 08 09:43:53.881  ATT Send         0x005E  <DEVICE_ADDR>  Write Request - Handle:0x004D - Value: 0100  
Jun 08 09:43:53.884  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0002    
Jun 08 09:43:53.909  ATT Receive      0x005E  <DEVICE_ADDR>  Write Response  
Jun 08 09:43:54.100  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0001    
Jun 08 09:43:55.656  ATT Send         0x005E  <DEVICE_ADDR>  Read By Type Request - Start Handle: 0x0001 - End Handle: 0x0007 - UUID: Device Name  
Jun 08 09:43:55.679  ATT Receive      0x005E  <DEVICE_ADDR>  Read By Type Response  
Jun 08 09:43:55.866  HCI Event        0x005E  <DEVICE_ADDR>  Number Of Completed Packets - Handle: 0x005E - Packets: 0x0001    
Jun 08 09:43:58.913  ATT Send         0x005E  <DEVICE_ADDR>  Write Request - Handle:0x004D - Value: 0000  
Jun 08 09:43:58.949  ATT Receive      0x005E  <DEVICE_ADDR>  Write Response  
Jun 08 09:43:58.953  HCI Command      0x005E  <DEVICE_ADDR>  Disconnect - Connection Handle: 0x005E - Reason: Remote User Terminated Connection  
Jun 08 09:43:58.966  HCI Event        0x005E  <DEVICE_ADDR>  Disconnection Complete - Success

arpa03 avatar Jun 08 '22 08:06 arpa03

Thanks for all of the info. We could just make that change to the example and call it good. But if we really want to understand what is going on some things I am curious about:

  • If we add a delay after calling the write method, does it eventually send a Write Command?
  • Does the characteristic being written to have both property flags set for write and write-without-response? We can see these flags by running python examples/service_explorer.py <device id> where <device id> is the UUID listed for the device by python examples/detection_callback.py.

dlech avatar Jun 08 '22 15:06 dlech

@dlech I encountered this issue, works on Windows, fails on Mac (Sonoma 14.4.1, M2 silicon). Could receive from device, but a send could not be observed.

I changed from response=False to True and it worked:

await client.write_gatt_char(tx_size, s, response=True)

below is the result of service_explorer.py for this device, does this reveal anything?

 py examples/service_explorer.py --address 779196B7-2C82-636C-68CA-1B0957D631D2
2024-03-25 22:44:52,915 __main__ INFO: starting scan...
2024-03-25 22:44:53,828 __main__ INFO: connecting to device...
2024-03-25 22:44:55,241 __main__ INFO: connected
2024-03-25 22:44:55,241 __main__ INFO: [Service] 0000fe59-0000-1000-8000-00805f9b34fb (Handle: 14): Nordic Semiconductor ASA
2024-03-25 22:44:55,241 __main__ INFO:   [Characteristic] 8ec90003-f315-4f60-9fb8-838830daea50 (Handle: 15): Buttonless DFU (write,indicate)
2024-03-25 22:44:55,299 __main__ INFO:     [Descriptor] 00002902-0000-1000-8000-00805f9b34fb (Handle: 17): Client Characteristic Configuration, Value: bytearray(b'')
2024-03-25 22:44:55,299 __main__ INFO: [Service] 00001623-1212-efde-1523-785feabcd124 (Handle: 18): Unknown
2024-03-25 22:44:55,359 __main__ INFO:   [Characteristic] 00001625-1212-efde-1523-785feabcd124 (Handle: 19): Unknown (read,notify), Value: bytearray(b'\x08\x01\x92\x02\t\x085\x10\x01\x1d=\x8aq@')
2024-03-25 22:44:55,419 __main__ INFO:     [Descriptor] 00002902-0000-1000-8000-00805f9b34fb (Handle: 21): Client Characteristic Configuration, Value: bytearray(b'')
2024-03-25 22:44:55,479 __main__ INFO:   [Characteristic] 00001627-1212-efde-1523-785feabcd124 (Handle: 22): Unknown (read,notify), Value: bytearray(b'\x0e\x00\x00\x00\x00\x00\x00\x00')
2024-03-25 22:44:55,538 __main__ INFO:     [Descriptor] 00002902-0000-1000-8000-00805f9b34fb (Handle: 24): Client Characteristic Configuration, Value: bytearray(b'')
2024-03-25 22:44:55,597 __main__ INFO:   [Characteristic] 00001626-1212-efde-1523-785feabcd124 (Handle: 25): Unknown (read,write), Value: bytearray(b'\x05\x00\x00\x00')
2024-03-25 22:44:55,657 __main__ INFO:   [Characteristic] 00001624-1212-efde-1523-785feabcd124 (Handle: 27): Unknown (read,write), Value: bytearray(b'\x08\x01\x8a\x02\x00')
2024-03-25 22:44:55,657 __main__ INFO: disconnecting...
2024-03-25 22:44:55,658 __main__ INFO: disconnected

orlyprofili avatar Mar 26 '24 02:03 orlyprofili

does this reveal anything?

I only see characteristics with the write property, so it is expected that response=True works and response=False doesn't work.

dlech avatar Mar 26 '24 13:03 dlech