RE: NUS Event Handling and Latency Measurements, (Single Packet Per Connection Interval)

Vidar Berg — Mon, 04 Jun 2018 13:10:30 GMT

Hi,

Notification packets passed to SD_BLE_GATTS_HVX are queued internally in the softdevice scheduler, which handles the packet transmission and ensure that max. number of packets are sent per connection interval. In other words, you should get max. throughput as long as the application keeps the output buffer full.

Transmission complete is signaled to the application through the BLE_GATTS_EVT_HVN_TX_COMPLETE event. This event can be combined with a ring buffer, etc if you want to avoid the while loop.

Also, the number of packets per connection interval depends on the time set aside for each connection, see sdk_config.h::NRF_SDH_BLE_GAP_EVENT_LENGTH. It's set to 320*1.25 ms in the throughput example.