Notify arrives late (timing problem)

RE: Notify arrives late (timing problem)

FormerMember — Thu, 27 Apr 2017 12:55:38 GMT

Could you use the LOG module to log when the notification is put in the TX buffer, when sd_ble_gatts_hvx() is called? And also log when the notification has been transmitted (BLE_GATTS_EVT_HVN_TX_COMPLETE)?

RE: Notify arrives late (timing problem)

Chris G. — Thu, 27 Apr 2017 08:09:48 GMT

Hello Kristin, the notification is working. Our problem is more the delay between the notifications. ie: when A(Smartphone) send a message to B(nRF52) on characteristic 1, B receive it successfully and send an ACK on charackteristic 2 back to B. So A can send the next message to B and so on.. Now our problem is, that the next message from A is received 300ms after the first message and i think this needs to much time.

RE: Notify arrives late (timing problem)

FormerMember — Thu, 06 Apr 2017 13:03:43 GMT

Setting char_md.char_props.notify = 1 will only set the notify property. However, the notification will not be enabled that way. To enable notifications for a characteristic, the client (often central/master) has to enable notifications by writing to the CCCD of the given characteristic.

In nRF Connect, there should be a button for enabling notifications for each characteristics that have the notify property.

RE: Notify arrives late (timing problem)

Chris G. — Thu, 06 Apr 2017 06:41:48 GMT

thank you for your response! The problem with nRF Connect APP is that i cannot test under the same conditions because i cannot influence the APP to send alot of write commands in a short time. Do you have an idea how i can test this?

i enable my notifications like this:

  if (p_char_settings->update == CHAR_UPDATE_NOTIFY)
    {
    char_md.char_props.notify = 1;
    }

RE: Notify arrives late (timing problem)

FormerMember — Mon, 03 Apr 2017 12:23:26 GMT

Do you see the same problem if you use nRF Connect (iOS)?

How do you enable the notifications?