BLE APP UART

RE: BLE APP UART

bjorn-spockeli — Thu, 10 Oct 2019 09:27:43 GMT

Hi Karelv,

Just to reply to your previous comment on pc-ble-drive-py installation.

I have not used the python bindings of the pc-ble-driver, but conflicting python installations could be an issue.

As for the nRF52840 dongle support, I know that its lagging a bit behind the pc-ble-driver thats written in C, which supports the nRF52840 dongle so if you're not locked to python, then you could use that instead.

[quote user="karelv"]
I wrote a little python script, it uses pygatt, which I believe does not work on windows...
In linux it worked.
Can you comment if this is the way to go?[/quote]

Which Windows version are you using? Could be that there isnt proper support for BLE in your particular version or that pygatt has not been updated to support the windows driver. On linux I would guess that its using Bluez which usually works like a charm.

I am not very experienced with pygatt so might not be the right person to ask. I have a javascript library called noble and a c library called gattool on a Raspberry Pi.

Best regards

Bjørn

RE: BLE APP UART

bjorn-spockeli — Thu, 10 Oct 2019 09:27:43 GMT

Hi Karelv,

Just to reply to your previous comment on pc-ble-drive-py installation.

I have not used the python bindings of the pc-ble-driver, but conflicting python installations could be an issue.

[quote user="karelv"]
I wrote a little python script, it uses pygatt, which I believe does not work on windows...
In linux it worked.
Can you comment if this is the way to go?[/quote]

I am not very experienced with pygatt so might not be the right person to ask. I have a javascript library called noble and a c library called gattool on a Raspberry Pi.

Best regards

Bjørn

RE: BLE APP UART

karelv — Wed, 09 Oct 2019 23:49:59 GMT

Hello Bjorn,

I wrote a little python script, it uses pygatt, which I believe does not work on windows...
In linux it worked.
Can you comment if this is the way to go?

Best regards,
Karel.

#!/usr/bin/env python

import binascii
import pygatt

from time import sleep

YOUR_DEVICE_ADDRESS = "11:22:33:44:55:66"
# Many devices, e.g. Fitbit, use random addressing - this is required to connect.
ADDRESS_TYPE = pygatt.BLEAddressType.random

adapter = pygatt.GATTToolBackend()
adapter.start()
device = adapter.connect(YOUR_DEVICE_ADDRESS, address_type=ADDRESS_TYPE)

uuid_write = None
uuid_notify = None

print("scanning {}:".format(YOUR_DEVICE_ADDRESS))
for uuid in device.discover_characteristics().keys():
  if str(uuid) == "6e400002-b5a3-f393-e0a9-e50e24dcca9e": # write PC to BLE-UART...
    device.char_write(uuid, bytearray([0x33, 0x33, 0x30]))
    uuid_write = uuid
    continue

  if str(uuid) == "6e400003-b5a3-f393-e0a9-e50e24dcca9e": # notify PC from BLE-UART...
    uuid_notify = uuid
    continue

  print("Read UUID %s: " % (uuid))
  print("%s" % (binascii.hexlify(device.char_read(uuid))))

print("notification mode..")


def cb_ble_uart(handle, data):
  print("cb_ble_uart", data)


device.subscribe(uuid_notify, cb_ble_uart)

for i in range(10):
  device.char_write(uuid_write, bytearray([0x33, 0x33]))
  sleep(1)

RE: BLE APP UART

karelv — Wed, 09 Oct 2019 22:26:35 GMT

Hello Bjorn,

I installed this driver, but my python3 installation complains:
ModuleNotFoundError: No module named 'Queue'

So installed using python2.7, it installs well, but it seems not to be able to import pc_ble_driver_py.

(can be due to my "abandoned" python2 installation...)

On top I found this issue:
https://github.com/NordicSemiconductor/pc-ble-driver-py/issues/64#issuecomment-477932904

So probably it won't work with my nrf52840 dongle anyways...

Best regards,
Karel.

RE: BLE APP UART

bjorn-spockeli — Wed, 09 Oct 2019 08:00:41 GMT

Hi Karel,

we do have the pc-ble-driver-py which is a serialization library over serial port that provides Python bindings for our nrf-ble-driver library.

Best regards

Bjørn

RE: BLE APP UART

karelv — Wed, 09 Oct 2019 02:06:53 GMT

Hello Bjorn,

Yes, understood!
Any idea if I can interface this BLE-UART from this demo from within a python program?

Thanks,
Karel.

RE: BLE APP UART

bjorn-spockeli — Thu, 03 Oct 2019 07:53:46 GMT

The UART/Serial Port Emulation over BLE example will not echo the sent data back to the Toolbox/nrf Connect/ NRf UART application, but it will send the data out on the UART of the nRF52. So if you send data from one of the smartphone apps then the sent message will be outputted on the UART of the nRF52 and vice versa, any data sent to the nRF52 over UART will be sent over BLE to the smartphone app.

Best regards

Bjørn

RE: BLE APP UART

karelv — Thu, 03 Oct 2019 00:07:56 GMT

Sorry, I was too quick; the example is a little more complex. It deals with 2 UARTs. Now I can receive info from nRF52 to toolbox app.

RE: BLE APP UART

karelv — Wed, 02 Oct 2019 23:29:45 GMT

In fact the nRF Toolbox / UART only can sent something to the nRF52, it never replies.
I added one line of code as I don't know how the toolbox is sending a \r or \n, such that it ends with a 0, it also echo the received string. So sending "test0" should trigger the nRF52 to send "test0" back to the toolbox-app, but it doesn't.

RE: BLE APP UART

karelv — Wed, 02 Oct 2019 23:09:46 GMT

Actually I am looking for a python way to interact with this BLE-UART.