Can a slave device send data without receiving an empty packet from the master device in a connection event?

[Subhanshu Sahu]

I have read that at each connection event master will send the first packet (empty payload).

In a case where slave latency > 1, the slave will not be listening to master for that many connection events that means will not be receiving the empty packet sent by the master at each new connection event, so in this case, can slave send data.

[ovrebekk]

Hi 

It is true that setting slave latency above 0 allows the slave to ignore an equal number of packets from the master, but it will only do so if it doesn't have any data to send. 

As soon as you upload some data to the Bluetooth stack on the slave side the slave latency sleep will be ignored, and the slave will respond on the next available event, ensuring that latency from the slave to the master is unchanged when using slave latency (making it ideal for applications like mouse/keyboard/remote, where you mostly care about slave to master latency). 

Otherwise there would be no point in using the slave latency feature at all, and you could just set a longer connection interval instead. 

Best regards
Torbjørn