Multilink - sending data to many peers

RE: Multilink - sending data to many peers

PW — Fri, 15 Jan 2021 13:22:23 GMT

I will check my idea and back here with some working solution. I guess :)

RE: Multilink - sending data to many peers

haakonsh — Fri, 15 Jan 2021 13:02:23 GMT

That might work, why don't you write some sudo code and show us?

RE: Multilink - sending data to many peers

PW — Thu, 14 Jan 2021 10:54:07 GMT

[quote userid="13562" url="~/f/nordic-q-a/70396/multilink---sending-data-to-many-peers/289097#289097"]Most BLE devices uses a static address and in that case the address is permanent and therefore an excellent method of identifying a device.[/quote]

I'm going to use devices with static address. So should I do it as I write in my first answer? I don't have another idea like assign reconnecting device to appropriate conn_handle accordingly with my structere which was create in my "write procedure" (write procedure: made one time, enabled by button, write address and conn_handle in flash). My idea follows from ble_app_multilink_central example, where I have to point at: "p_ble_lbs_c " to send data. Maybe there is a better method?

RE: Multilink - sending data to many peers

haakonsh — Thu, 14 Jan 2021 09:35:59 GMT

The connection handle does not belong to a device, but an index of connections in the BLE controller(f.ex 0-7). Once a connection is broken the connection handle is released and it will be given to the next connection that is established. Since you cannot control which device connects in what order you cannot use the connection handle to identify a device once its connection is broken. Therefore you must use another set of information such as address, UUIDs, device name, RSSI, or Identity Resolving Key.

Most BLE devices uses a static address and in that case the address is permanent and therefore an excellent method of identifying a device.

However there are some devices that has a revolving address that is changed after its connection is broken, in that case you need to get its Identity Resolving Key in order to identify the device(new address each time you connect to it). This privacy mode is used by devices that does not want to be tracked by 3rd parties.

RE: Multilink - sending data to many peers

PW — Wed, 13 Jan 2021 19:46:11 GMT

So in that case, I should probably check address while peer connect to central and assign it with right conn_handle. This conn_handle which was write in my "write procedure". And I'm little confused, because I don't know how does central device knows which peer to send data to? I thought that is address :)

RE: Multilink - sending data to many peers

haakonsh — Wed, 13 Jan 2021 08:26:47 GMT

Addresses are not stored, unless you use bonding. If you do not want bonding, then you will have to store the addresses to flash yourself.