BLE specification

[sherin]

The BLE specification core 4.0 imposes certain limitations.

1. Min connection interval 7.5ms
2. Data payload on connection 27 bytes (the length field is 5 bits)

What is the reason behind such limitations?

[FormerMember]

Here's a page from 'Bluetooth Low Energy The Developer's Handbook' which explains why short packets are used. Amazing book to get started. I am guessing that the reason for the min connection interval of 7.5 ms is also the same i.e to prevent the chip from heating up, reducing the overall power consumption and enabling the use of button/coin cells. Hope this helps. Prithvi

Edit: Please take this down if there is any copyright infringement with posting of this picture.

[sherin]

Tx Prithvi.

[sherin]

I understand that notifications are link level ack-ed. But can I see this ack when i just have a DSO? I am able to see the packet transmissions.

Can I see this link level ack in a packet capture using sniffer?

[FormerMember]

Yes, the link-level acknowledgements can be seen in the packet sniffer software provided by Nordic Semi. You can see a preview of it in figure 5 in the nrf Sniffer User Guide 1.1 in the columns of SN and NESN.