1-1 permanent connection between central and peripheral

RE: 1-1 permanent connection between central and peripheral

Amanda Hsieh — Thu, 22 Apr 2021 08:38:46 GMT

Hi,

[quote user="QuentinFarizon"]I was indeed testing with nRF Connec. I see that I can able a bond from nRF Connect, but how can I initiaite pairing without bonding ?[/quote]

Click the settings button for the device in nRF Connect for Desktop, select "Pair". Then, click "Pair". Wait until the pair is established before you continue.

[quote user="QuentinFarizon"]But I don't see any sdk examples using these parameters. Do you have an example application that is not provided with the SDK ?[/quote]

Unfortunately, we don't have that, but you can modify the security parameters of the Template Application to achieve that.

[quote user="QuentinFarizon"]The goal is to use my central device which is a NRF52832. From there, how can I initiate pairing without bonding ? What example can I look at ?[/quote]

You can take a look at the BLE Heart Rate Collector Example which initials bonding from central with pm_conn_secure. The example is using LESC pair parameters, but the procedure is the same.

[quote user="QuentinFarizon"]is there a way to connect to a bonded non-advertising peripheral ? How ?[/quote]

No, the peripheral has to advertise after disconnect.

[quote user="QuentinFarizon"]how can I implement a 1-1 connection between a central and peripheral, that supports disconnections from either side ?[/quote]

Did you play around Heart Rate Application and BLE Heart Rate Collector Example? The examples support pair with whitelist which can restrict the specific connection. After disconnecting with the central (hrs_c), the peripheral (hrs) will adverse again. This might help your issue.

-Amanda H.

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Thu, 22 Apr 2021 08:21:30 GMT

Ok I succeeded with JustWorks bonding. I guess it's not possible with "pairing, no bonding".

Peripheral still advertises when central disconnnects, but refuses all connections.

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Wed, 21 Apr 2021 16:50:40 GMT

To try to make some progress, I have tried using bonding on my perihperal and to iniate bonding from my central (or from nRF connect).
I have looked at ble_app_hids_mouse that does exactly that.

What I don't get is that once the central disconnects, the peripheral does not advertise, so it can't reconnect ...
Or is there a way to connect to a bonded non-advertising peripheral ? How ?

I feel like I'm still at the start of the conversation : how can I implement a 1-1 connection between a central and peripheral, that supports disconnections from either side ?

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Wed, 21 Apr 2021 12:38:58 GMT

I was indeed testing with nRF Connec. I see that I can able a bond from nRF Connect, but how can I initiaite pairing without bonding ?

On the peripheral, I have configured pm_sec_params_set with the "Pairing, no bonding" configuration (from https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.0.2%2Flib_pm_usage.html&cp=7_1_3_2_7_2)
But I don't see any sdk examples using these parameters. Do you have an example application that is not provided with the SDK ?

The goal is to use my central device which is a NRF52832. From there, how can I initiate pairing without bonding ? What example can I look at ?

RE: 1-1 permanent connection between central and peripheral

Amanda Hsieh — Tue, 20 Apr 2021 08:16:10 GMT

Hi,

What is your central device? Does it initial bond? If you are using ble_app_hids_mouse, see HID Mouse Application.

-Amanda H.

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Mon, 19 Apr 2021 13:00:03 GMT

Sorry, this is a typo from my side : I use pm_sec_params_set after pm_init with the "Pairing, no bonding" configuration.

My question still stands, I am never called on PM event PM_EVT_PEER_DATA_UPDATE_SUCCEEDED

RE: 1-1 permanent connection between central and peripheral

Amanda Hsieh — Mon, 19 Apr 2021 11:52:44 GMT

Hi,

[quote user="QuentinFarizon"]I used the "No pairing/bonding" mode.[/quote]

You need to enable pair or bond to call pm_sec_params_set. See Peer Manager/Usage and Security parameters docs.

-Amanda H.

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Fri, 16 Apr 2021 14:54:47 GMT

Ok so on the peripheral I added the Perr Manager + whitelisting, based on ble_app_hids_mouse.

However, I am never called on PM event PM_EVT_PEER_DATA_UPDATE_SUCCEEDED, which calls the whitelist_set in hids_mouse.
In fact, I'm getting no events in pm_evt_handler

I have checked that peer manager is initialized
I have set PM_LOG_ENABLED, but I don't see any logs pertaining to PM or errors.

I used the "No pairing/bonding" mode.

RE: 1-1 permanent connection between central and peripheral

Amanda Hsieh — Fri, 16 Apr 2021 08:22:37 GMT

You would need to use bonding and whitelisting so that the devices will reject connection from devices outside of the whitelist.

This feature is supported by the softdevice and implemented in the peer manager libary: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.2/lib_pm_functionality.html?cp=7_1_3_2_7_1_2#lib_pm_functionality_whitelist

You can refer to our example ble_app_hids_mouse (or keyboard). In the example, after bonding we will do directed advertising and after that will do whitelisting advertising, after the whitelist advertising timeout, it will advertise in normal mode.
To be able to make sure there will be no other device to connect to your device, you can disable the timeout to normal mode. Only advertise in whitelisting mode.

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Fri, 16 Apr 2021 06:28:36 GMT

Is it then possible for the peripheral to forbid connections from other centrals ?

How do you suggest to implement the fact that the peripheral is "reserved" for a given previously connected central?

RE: 1-1 permanent connection between central and peripheral

Amanda Hsieh — Fri, 16 Apr 2021 06:24:06 GMT

Hi,

[quote user="QuentinFarizon"]If the peripheral doesn't advertise, isn't it possible for the central to connect using the peer address.[/quote]

A peripheral device broadcasts info about itself using advertising. The central device will scan for advertisements, and analyze the advertisements found in the scan result.

[quote user="QuentinFarizon"]I didn't meant a perihperal reset, I meant a peer reset (to allow the peripheral to be "free" and be scannable/connectable by another central)[/quote]

You can take a look at this Bond Management Application which you could write a command to to the Bond Management Service Control Point Characteristic (0x2AA4) to delete the current bond.

-Amanda H.

RE: 1-1 permanent connection between central and peripheral

QuentinFarizon — Thu, 15 Apr 2021 16:30:15 GMT

> I doubt that How the peripheral knows the central is power off and on to advertise or not.
The peripheral can know the central disconnected.
If the peripheral doesn't advertise, isn't it possible for the central to connect using the peer address.

> You could send strings to the peripheral and handle it to execute NVIC_SystemReset();
I didn't meant a perihperal reset, I meant a peer reset (to allow the peripheral to be "free" and be scannable/connectable by another central)

RE: 1-1 permanent connection between central and peripheral

Amanda Hsieh — Thu, 15 Apr 2021 13:09:46 GMT

Hi,

[quote user=""]- when central is powered down, peripheral must not advertise
- when central is powered up with a peer stored, it should connect to it[/quote]

I doubt that How the peripheral knows the central is power off and on to advertise or not.

[quote user=""]A) From what I gather from the documentation, I guess the correct way to implement this is with the peer manager + whitelist with a maximum link of 1. Is this correct ? Is there a simpler/other API ?[/quote]

That is correct. You can take a look HID Mouse Application for whitelist, and Heart Rate Application for Peer Manager and LESC pair. You might be interested in this similar case.

[quote user=""]B) Is the reconnect automatic at start with the peer manager ? If not, what is the function for that ? scan with whitelist ?[/quote]

No, you could scan and connect with the whitelist. See this post.

[quote user=""]C) Is this possible with the "No pairing/bonding" mode of peer manager ? If not, is "Pairing, no bonding" the way to go ?[/quote]

Yes, see Security parameters for Pairing, no bonding.

[quote user=""]D) Is there a standard way for the central to indicate to the peripheral to reset peer or should I create a custom service for that ?[/quote]

You could send strings to the peripheral and handle it to execute NVIC_SystemReset();

-Amanda H.