data dose not sent with specified connection interval

RE: data dose not sent with specified connection interval

Vidar Berg — Thu, 21 Jun 2018 11:04:23 GMT

I don't see any benefits of adding sd_ble_gatts_hvx() to the app scheduler queue, I'd suggest to call it as soon as you've read out the data from flash. sd_ble_gatts_hvx() adds the notification packet to the softdevice's internal scheduler queue.

As a test, please try to always keep more than one packet queued in the softdevice scheduler and check if the central is receiving one packet for every connection event in that case.

Indications are significantly slower because the central needs to acknowledge each packet with 'ATT handle value confirmation'.

RE: data dose not sent with specified connection interval

alireza sadeghpour — Wed, 20 Jun 2018 13:37:56 GMT

after BLE_EVT_TX_COMPLETE i call a function, in this function i call fds_record_find & fds_record_open function to open a flash record to read, then i copy 20Byte content from opened record to an array and then i put an task in queue with app_sched_event_put function, when the task started i call sd_ble_gatts_hvx() function to send data over bluetooth and again i wait for BLE_EVT_TX_COMPLETE event to start the process again.

i gave also other question, if i change charactristic type from notification to indication it can help to make performance better?? in central i have a limit that can receive only one packet at a time, what happen if i change char type to indication and queue six packet in ble stack to send it one by one in each connection interval.

thanks for your response.

RE: data dose not sent with specified connection interval

Vidar Berg — Wed, 20 Jun 2018 11:49:01 GMT

Hi,

Are you doing anything else in the BLE_EVT_TX_COMPLETE apart from reading data from flash, and do you see the same if you queue more than one packet at a time? 25 ms connection interval should give the application plenty of time to read data from flash and add it to the tx buffer for the following connection event.