Help switching from notification to indication

RE: Help switching from notification to indication

Petter Myhre — Mon, 24 Apr 2017 12:45:24 GMT

Great! All packets will be retransmitted until the supervision timeout is hit, if it is hit, the link is considered lost/disconnected.

RE: Help switching from notification to indication

Mufasa1 — Fri, 21 Apr 2017 17:22:44 GMT

Hey Petter I added the sd_ble_gattc_hv_confirm to the central code when It receive an indication from the peripheral and in the peripheral code BLE_GATTS_EVT_HVC event when it receive the indication confrimation from the central after it I disconnect the two devices. It is working for now pretty good I am testing in case I lost some packet, in case a lost packet the peripheral send it again or do I have to wait 30sec for the timeout?

RE: Help switching from notification to indication

Mufasa1 — Fri, 21 Apr 2017 13:47:04 GMT

So do I have to wait for BLE_EVT_TX_COMPLETE before kill the connection? I am going to test because now I am thinking a posible reason when I have a packet lost: In case the a packet lost I kill the connection to early, but I stll haven't any verification the BLE_EVT_TX_COMPLETE to do any retransmission in case this applies? Or how can I handle a packet lost when sending notification/indication to a central device

RE: Help switching from notification to indication

Petter Myhre — Fri, 21 Apr 2017 07:33:07 GMT

You will not lose any more packets with notifications compared to indications, they are both acked and retransmitted at the link layer. The difference is that indication has to be acknowledged at the application layer. See this for more information. If the central doesn't receive notifications at longer ranges it is probably because it is not receiving any packets at all.

RE: Help switching from notification to indication

Petter Myhre — Fri, 21 Apr 2017 07:28:41 GMT

Why are you disconnecting? You should get a confirmation, but are you actually confirming the indication in the central application?

RE: Help switching from notification to indication

Mufasa1 — Fri, 21 Apr 2017 06:37:42 GMT

Petter an aditional issue I am getting is... the central some times dont receive the notifications (data loss) when the two devices are 25feet+ away that is the main reason I am switching to use indications in case it helps to avoid data lost or in case a packet is not received. Using a sniffer I see the notification from the peripheral but for some reason the central does not receive it.

RE: Help switching from notification to indication

Mufasa1 — Thu, 20 Apr 2017 16:21:04 GMT

The following are the examples I am testing and the changes I made are marked ////changes ble_app_blinky_c.rar

experimental_ble_app_blinky.rar

Thanks :)

RE: Help switching from notification to indication

Mufasa1 — Thu, 20 Apr 2017 15:39:41 GMT

I solved it. I was killing the connection to early and calling the indication too late in the peripheral code.

The only concern I have is where is the indication ACK confirmation?

Or Do I have to handle it on code level? because I need verificate I received the data on the central module. I read about an ATT_Handle_Value_Confirm

Regards

RE: Help switching from notification to indication

Petter Myhre — Wed, 19 Apr 2017 11:58:36 GMT

Maybe you can upload the sniffer trace? Are you successfully calling sd_ble_gatts_hvx()? No error?

RE: Help switching from notification to indication

Mufasa1 — Tue, 18 Apr 2017 23:10:41 GMT

Petter, I was my mistake the Central and the Peripheral can connect between them but the Peripheral is not sending the indication to the Central, The central send the cccd 2 to the peripheral but it last is not responding

RE: Help switching from notification to indication

Petter Myhre — Tue, 18 Apr 2017 15:17:45 GMT

I don't see how the changes you have done would cause not being able to connect. You don't even see a connection request on the sniffer trace? Or are they able to connect, but disconnect quickly?