CC2640R2F: How to connect a SimpleCentral based application to several Peripheral

Hello Clément,

Are you French ?!

So, for the first question, my answer is yes, I changed the MAX_NUM_BLE_CONNS up to 3 (this is the max number of devices I want to allow).

Then, I checked the status returned by GapInit_connect() : it indicates that it's already performing that task (bleAlreadyInRequestedMode 0x11 is returned).

So, I tried to add a TaskSleep in my connect loop. The idea was to free CPU time for the task to catch and process the GAP_LINK_ESTABLISHED_EVENT. It is not able to connect to my 3 peripheral at the same time (with the TaskSleep delay between each). This is probably not the best way to do but it confirm that this is the reason at this step.

But, I'm still blocked at the next step : In SimpleCentral example program (which is the template program I used for my application), when GAP_LINK_ESTABLISHED_EVENT is received, there is a call to a "SimpleCentral_doSelectConn()" function, for one of the established connections, which send an internal SC_EVT_SVC_DISC event to the main "ProcessAppMsg()" function. On this event received, a "SimpleCentral_startSvcDiscovery()" is then called, which performs a GATT_ExchangeMTU event, starting the Service discovery for this connection. 

If I select one of the 3 established connections, Service discovering is OK and I can write in my Peripheral Characteristics.

But I don't know how to proceed at this step to have both my 3 connexions selected and Service discvovered on each of them simultaneously.

Is it possible ?

From your experience, what should be the best way to proceed ?

THank's again!

Patrick

Just use multi role example program to connect to up to 3 peripheral.

-kel

Hello

Yes, I already looked into this example program, but I couldn't do exactly what I want :

In fact, I need to connect and exchange data with several peripherals simultaneously. From what I could understand in the multirole example, the device discovering allow to discover all of them, but the connection and service discovery is made one by one.

Is that the only way to do, or is it possible to discover all devices, then select all my 3 connections and have all of them openned to write in parallel in the discovered characteristics of each ?

THanks

Patrick COMBETTE said:

From what I could understand in the multirole example, the device discovering allow to discover all of them, but the connection and service discovery is made one by one.

Once the 3 peripherals pair to the multi role, you can set it to reconnect using the menu, from what I remember. So next connection the 3 peripherals will connect simultaneously.

Just a caution with connection multiple peripherals to multi role, it requires memory. If you have memory problems at multi role side you will experience disconnection.

Maybe you can do this the ibeacon or eddystone beacon way.

-kel

Hi Patrick,

Yes, I am French :)

Can you tell us if the solution offered by Markel Robregado could help you?

Kind regards,

HEllo,

In fact, the solution you proposed, didn't fully help me, but a little bit !

I could modify the SimpleCentral example to discover and connect to all my Peripherals, but I'm still not able to Select all connections and write to each of them.

As you mentionned, I encountered a memory size issue and was obliged to reduce Stack sizes to prevent this (I had intempestive disconnections). This side is solved now.

I observed that in the SimpleCentral example program, the way used to select a connection and permform read and write operations in characteristics on a discovered and connected device, is based on a "doSelectConn()" function which itself starts the ServiceDiscovery. But these functions use a common 'scConnHandle' variable pointing to the connection and used for all subsequent functions.

I think I need to change this....

ANyway, I'm not sure of the best way to program this algorithm...

I hou have any idea or suggestions, you're welcome !

If you need I can post my modified code for SimpleCentral, just let me know.

THanks again !

Patrick

Hi !

Ok, so we could speek Frenche, but for other people It's better to conitinue in English !

You can see the reply I sent to Markel,

In fact I have progressed a little bit but still have problems to select all established connections and start Service discovery sucessively on each of them, automatically (without button menu).

THank's for help.

Bonne soirée !

Patrick

Hello Clement,

At first I wish you a very happy ney year.

I just restart my project after some holiday !

So, I confirm that my propblem is to write data to all my connected devices. I successed to discover devices (peripherals), to connect them, but still not found a way to write them at the same time (or with a little time delay).

Regarding to my initial post about this topic, 2 of the 3 steps are now OK in the processing :

 _doDiscoverDevice()

_doConnect()

The next step I don't know how to manage is the _doSelectConn() : I can choose one connection in the list (connList[] variable), then select it, start service discovery, and finally write to the wanted  characteristic. But I don't understand how to do this simulaneously or sequentially but small delay between each. The limitation is due to the fact that there is only one global variable used to record the selected connection ('scConnHandle' ). What would you recomment to do that ?

Best regards

PAtrick

Hi Patrick,

Glad to have you back. Happy new year to you too!

If you problem is having only one connection handle, then why are you not declaring one or two more? You can have a look to the way multi_role example is handling the variable connHandleMap. You will see that a memory allocation is done using ICall_malloc() and a function (multi_role_mapConnHandleToIndex) has been written to find to which connection a given connection handler is belonging.

I hope this will help,

Regards,