BlueNRG-MS: Impossible to transmit multiple Write Requests in a single Connection Event?

[hardware]

Posted on April 12, 2017 at 20:48

Hi,

I have noticed that it is not possible to have multiple ACI_GATT_WRITE_CHAR_VALUE per connection event.

I have set up the following connection: connection interval of 40ms and connection event length of 21.875ms (the maximum I can while continuing to advertise in parallel).

Using a sniffing tool, I see that what is happening is the following:

- Master -> Slave : Write Request

- Wait for 40ms (next connection interval)

- Slave -> Master : Write Response

- Wait for 40ms (next connection interval)

- Master -> Slave : Write Request

- etc.

Is that a normal behavior? Why isn't it possible to have the Write response inside the same connection event, and more write reqests?

Note that if I use ACI_GATT_WRITE_WITHOUT_RESP (Write command), I don't face the issue, and it's possible to send multiple ones inside the same connection event (around every 700us)

Thanks for your help.

Christian

#bluenrg-ms

[Andrea Palmieri · Accepted solution]

Posted on April 19, 2017 at 10:42

Hi Christian,

yes, it is an expected behavior since the slave will wait for its own connection interval to send the response required by the ACI_GATT_WRITE_CHAR_VALUE.

Kind regards

Andrea

[hardware]

Posted on April 26, 2017 at 20:55

For my education, would you mind pointing me to the reference in the Bluetooth CORE Specifications?