Central and Perpheral transfer speeds

[firmware_master]

Hi,

In the BLE_UART example, I am trying to get some data about the time delay between the sending and the receiving of data between central and peripheral devices.

I noticed that the time taken for messages from peripheral to central takes lower time compared to central to peripheral. I simply wanted to know why does this phenomenon occur.

Thanks

[Simon]

In the ble_uart examples the peripheral is the server and the central is the client, which means the peripheral holds the GATT server.

I assume the devices are in a connection (not advertising/scanning), and that is where you see the big difference is transfer speed. I assume the difference in speed comes from the fact that the server (peripheral) sends notifications to the client (central) about changes in the GATT database, while the client writes to the servers GATT database.

I don't think the on-air-time (radio from radio) of the messages should vary much, but since a write transfer requires the GATT database to be updated it may take more time in that direction.

I have not tested this myself, and I don't know for sure if this is the reason you are seeing the difference in speed.

Best regards,

Simon