6 notifications in one connection interval related issue

RE: 6 notifications in one connection interval related issue

run_ar — Fri, 28 Apr 2017 13:30:30 GMT

You will only use more power if you send more packets. So if you send 3 packts per connection even on BW_MID, that will use less power than sending 6 packets per connetion event with BW_HIGH given you use the same connection interval, same packet length. But you are also sending twice as much data.

Assuming you have a given number of packets you need to send, You will be able to send them in fewer connection event using the HIGH setting. In that case there might be a penelty if you end up sending more empty packets with the High configuration compared to MID or LOW. so it depends on your application and what it does.

I would recommend looking at the online power calculater as that will tell you the carge you use in each event in µC. So you can apply that to your use case.

RE: 6 notifications in one connection interval related issue

bihu — Tue, 25 Apr 2017 07:51:58 GMT

Thanks!

Another issue about the power consumption. The connection has same parameter. Does BLE_CONN_BW_HIGH takes more power than BLE_CONN_BW_MID or BLE_CONN_BW_LOW? Do you has test report about this?

RE: 6 notifications in one connection interval related issue

endnode — Mon, 24 Apr 2017 08:00:30 GMT

Here is the hint.

RE: 6 notifications in one connection interval related issue

bihu — Mon, 24 Apr 2017 06:38:07 GMT

Thanks!

I get the SPEC from infocenter.nordicsemi.com/.../S130_SDS_v2.0.pdf. I only see the recommend stack configuration. But I didn't see it for connection count and bandwidth from chapter 15.3 and 11.4. Does it automatic allocated?

RE: 6 notifications in one connection interval related issue

endnode — Mon, 24 Apr 2017 02:19:29 GMT

Please see some recent question about Soft Device initialization (there is at least one per week), you will see how to find out exact RAM resources for your Soft Device with given GAP (connection count and bandwidth etc.) and (G)ATT (number of custom 128-bit UUID bases, MTU size etc.) configuration.

RE: 6 notifications in one connection interval related issue

bihu — Mon, 24 Apr 2017 01:21:32 GMT

Another question about the memory. What difference between BLE_CONN_BW_HIGH and BLE_CONN_BW_MID? How many RAM we need reserve for high performance?

RE: 6 notifications in one connection interval related issue

bihu — Mon, 24 Apr 2017 00:43:17 GMT

`ble_common_opt_conn_bw_t opt_conn_bw;

// connection BW settings to be used by the next connection established. opt_conn_bw.role = role; opt_conn_bw.conn_bw.conn_bw_tx = BLE_CONN_BW_HIGH; opt_conn_bw.conn_bw.conn_bw_rx = BLE_CONN_BW_HIGH;

return sd_ble_opt_set(BLE_COMMON_OPT_CONN_BW, (ble_opt_t const *)&opt_conn_bw); `

The previous code can make stack send out more than 3 packets per-connection interval.

RE: 6 notifications in one connection interval related issue

run_ar — Fri, 21 Apr 2017 13:58:56 GMT

Please reference the message sequence chart for Bandwidth configuration available here.

RE: 6 notifications in one connection interval related issue

bihu — Fri, 21 Apr 2017 00:37:00 GMT

The MD flag is set as 1 when switch to next connection periodic. So I think the Soft Device has enough data. In my test environment, both peripheral and central are used NRF51822. I don't know how to set the packet supporting in the link layer. Can you provide me some API to set this parameter in SD V2.0?

RE: 6 notifications in one connection interval related issue

endnode — Thu, 20 Apr 2017 11:15:01 GMT

Important question: do you provide enough Tx data ("packets" if you want) to Soft Device before connection event (so it has even chance to send multiple of them on the other side) and does the other side of the link support more then 3 packets? Or do you test the same nRF5x board with similar FW running on top of the same SoftDevice?