2 x nRF52840 used as client/server to make them communicate through python

[Dan_]

Hi, I'm trying to use two nRF52840 Dongle to make them communicate as server/client with a script in python, I succeeded on making them have a session with the test example given in the pc_ble_driver_py library but now I'm trying to create a script myself so that I can manage the custom UUIDs and the data exchanged between the two devices.

Since I'm not an expert on pyhton I have some difficulties understanding in a good way how to use the pc_ble_driver_py library(directly from that one script) to create a full custom session and I could not find any documentation with instructions/information.

Do you have some documents for this python library(in GitHub there is not such a document)?  If not do you have other examples on how to implement and use this library in a script so that I can work with?

Thank you in advance.

[Sigurd]

Hi,

Did you have look at this file? https://github.com/NordicSemiconductor/pc-ble-driver-py/blob/master/pc_ble_driver_py/examples/heart_rate_collector.py

Jørgen also created something for nordic uart service here:  RE: How to use PCA10040 as Dongle Scanner 

There is not much documentation on this, expect for what's in the README, https://github.com/NordicSemiconductor/pc-ble-driver-py/blob/master/README.md

[Dan_]

Thank you for the answer,

I have already checked these documents/links but they don't help much to understand in a good way how to best implement this library, even the "pypi.org/project/pc-ble-driver-py/" page (where usually I can find documentation) is blank. 

What can be very useful is a document with the explanation of the functions that can be used in a python script to setup a connection (with a full session).

In  test/test_server_client.py(GitHub) it is shown just a notify example but what about indicate or read/write? How can I use them?

[Sigurd]

Hi,

Dan_ said:

What can be very useful is a document with the explanation of the functions that can be used in a python script to setup a connection (with a full session).

Much of the terminology and naming of defines, variables, etc is from the SoftDevice, so the SoftDevice documentation could help. E.g. this function. https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s140.api.v7.3.0/group___b_l_e___g_a_t_t_s___f_u_n_c_t_i_o_n_s.html?cp=5_7_4_1_2_4_2_4#ga313fe43c2e93267da668572e885945db

Dan_ said:

In  test/test_server_client.py(GitHub) it is shown just a notify example but what about indicate

In there we have this function,

def send_data(self, data):
hvx_params = BLEGattsHVXParams(
handle=self.char_handles,
hvx_type=driver.BLE_GATT_HVX_NOTIFICATION,
data=data,
)
self.adapter.driver.ble_gatts_hvx(self.conn_q.get(timeout=2), hvx_params)

change BLE_GATT_HVX_NOTIFICATION to BLE_GATT_HVX_INDICATION to send indication instead. (But the characteristic need to support it as well)

For Write we have this function: write_cmd ( def write_cmd(self, conn_handle, uuid, data, attr_handle=None)
For Read we have this function: read_req ( def read_req(self, conn_handle, uuid, offset=0, attr_handle=None)

[Dan_]

I managed to implement the indicate with a complete session(but without visualizing the ack, any idea on how to do it? ), now I'm trying to use the write function but I have the previous problem.

Can I ask you to give me an example (based on the "test_server_client.py" file) in which you implement the write with and without ack function (for a complete Central/Peripheral session)? 

Thank you

[Sigurd]

Hi,

I don't have any examples, but to verify and "visualize", the behavior, you could use the nRF Sniffer: https://www.nordicsemi.com/Products/Development-tools/nrf-sniffer-for-bluetooth-le