Connect to device in 2 different ways to distinguish between masters

[DS4]

My device is the slave, that is being connected (not always in the same order) by 2 masters.

I would like to create two different connection ways/points to distinguish between the masters.

 

MASTER1 will always connect through "way1."

MASTER 2 will always connect through "way2."

And I could map the connection handles according to the way they connected.

 

What could "way1" and "way2" be?

 

I was thinking about changing the MAC address/Name I am advertising periodically, by that creating 2 connection points.

First master will always connect through MAC1/NAME1.

Second master will always connect via MAC2/NAME2.

 

Is it possible? Could I see that info in the message I am reviving?

 

 

Is there another way?

 

 

Thanks.

[ovrebekk]

Hi

Can't you just have MASTER1 and MASTER2 send a data packet once the connection have been established, to identify themselves to the slave as either MASTER1 or MASTER2?

To do this you can set up a proprietary characteristic for this specific purpose, and the master can send a data update on this characteristic. 

It should also be possible to do as you say and have the slave alternate between two advertise packets, but this would make the code on the slave side a bit more complex. 

Best regards
Torbjørn

[DS4]

Thanks!  

Propriety characteristic can definitely work.

But our goal is to keep it simple on the master side, and do the work on the slave.

(We considered scanning and reading the masters ID characteristics)

But before that would like to test the alternation method.

For that it is important for me to know through which MAC the master's were initially connected.

Can I get that info? if yes, how?

[ovrebekk]

Hi

When you establish a connection the BLE_GAP_EVT_CONNECTED event will occur, and in this event you can read out the BLE address of the peer device that you just connected to. 

 Assuming the ble_event_handler is implemented as in the standard examples you can get access to the peer address like this:

p_ble_evt->evt.gap_evt.params.connected.peer_addr

Best regards
Torbjørn

[DS4]

Hi thanks again,

The peer address is how the master saved my address?  

What I meant is supposedly I am advertising alternating "MAC1" and "MAC2".

Started advertising. 

Salve gets an ISR connection.

How can the slave know (100%), if this ISR master connected through MAC1 or MAC2?

Thanks.

[ovrebekk]

Hi 

The most reliable way to do this is to change the BLE device address on the advertising side, instead of just changing a value in the advertising payload. 

When the application on the master side tells the stack to establish a connection you use the BLE device address to decide which advertiser to connect to, so this is the most reliable way to ensure that the master connects to the right advertiser. 

On the slave side you will need to reconfigure the BLE device address periodically. Whenever the connected event occurs you know that the master that connected to you did it over the currently configured BLE device address (which you can map to MAC1 and MAC2). 

Best regards
Torbjørn

[DS4]

This solution sounds great, but I feel it might not be prefect. 

"On the slave side you will need to reconfigure the BLE device address periodically. Whenever the connected event occurs you know that the master that connected to you did it over the currently configured BLE device address (which you can map to MAC1 and MAC2)."

My concern about this solution is of a race.

By the time the connection ISR occurs, I may already change the system MAC. 

Is there a way to get this 100% accurate?

Maybe a different ISR? Or a  way to read the destination MAC address from the masters packets? Or any other way..

Thanks