Transfering Data between two Rpis using BLE

[sid20]

i want to establish connection mode of ble between two rpis to advertise some data . Can anyone help?

[Douglas6]

Possibly. What's your question?

[sid20]

I have some data that i am reading from a i2C mpu 9250 , one Rpi is taking that data , i want to advertise it
I want that data to transfer/advertise using connection mode of BLE between two Rpis , using their inbulit BLE.
I am successful in enabling advertisement mode.
But I want help for connection mode.
Connection mode i mean here it is i want to set packet length , time interval from recieving rpi
Help me out.

[sid20]

simply i wanna ask , how to connect two rpis using ble?
I tried gatttool , it showed up connect error connection refused(111)

[Douglas6]

There are no services running out of the box on the Pi, so no connection to be made. You'll need to set up a service on one Pi (the 'peripheral'), and add at least one characteristic. You'll need to start advertising on the peripheral. Then, on the other Pi (the 'central'), you should be able to connect and read/write the characteristic.

[sid20]

Yes thanks I did this, now i am doing it in command line , now i want to read write heart rate data using bluepy package of python.
i dont know how to do it in python . help me out.....

[Douglas6]

There's sample Pi code in the test directory of the BlueZ github (example-gatt-server and example-gatt-client). They interface directly with BlueZ through its D-Bus interfaces. You can't use bluepy for central coding. There's a Python port of the node.js bleno library, but I've never used it.

[sid20]

yes , excample gatt server gatt client is advertising data and other is scanning , now I wanna establish connection to modify or read write data using the other rpi which is recieving the advertising data using python? i hope you understand.


it is avery imp project for me.

[Douglas6]

If you have the peripheral working, you can either use example-gatt-client on the central Pi, or use bluepy to create the client, and connect to and read/write characteristics from the peripheral. Lots of examples on the Internet.

[sid20]

please share some,
when i run gatt client it shows no heart rate service found , how to rectify that? this time gattserver is running but gattclient shows this too.
this both are running simultaneously in different pi

[sid20]

plz reply anyone..........?

[Douglas6]

Are you running example-advertisement on the peripheral?

[sid20]

yes i am running it,

i want now to write a characteristic data uuid using bluepy in python,
i am able to read , get characteristics, services all, but now need your help in writting the advertised data

[sid20]

ok thanks

[Gavinmc42]

BLE is working in baremetal.
https://ultibo.org/forum/viewtopic.php? ... =ble#p8635
Even works between Microbits and Pi's.

Have you tried uart mode?
It was a utility example for Nordic? chips that now seems common and very useful for simple data.

[sid20]

sorry ,i didnt get .Can you please explain what you have shared?

[Douglas6]

Here's some code I have to write a characteristic using bluepy: viewtopic.php?f=28&t=193923&p=1214901#p1214901

[sid20]

i want to write using handle not using uuid of ble....,
if you have any please share