ble peripheral awaken from deep sleep

[astella]

To the kind attention of Nordic support team,

I'm interested in a ble example (SDK15.2 nRF52840 nRF52832) where peripheral device is waken up from being in deep sleep mode, when receiving a central message.

I mean, from what I'm reading in https://devzone.nordicsemi.com/f/nordic-q-a/10242/who-and-how-wakes-up-cpu-when-ble-notification-is-received it seems that there is

a timing agreement between peripheral and central. I'd like to understand if this timing agreement is the only way, or there is the possibility to awake a peripheral device from a deep sleep

using a complete special asynchronous message coming from central. Obviously peripheral should be able to have antenna listening without too high consumption. 

Hope to be clear. Is there an example like this?

From what I know both Peripheral and Central supports bi-directional data transfer. I wanted to well understand by Bluetooth Specifications if,

after a connection has been created, it is possible for peripheral device to go in deep sleep mode waiting a Central message in order to be awaken up. 

Should be the case, may ask to Nordic experts to help me find where this is defined in bluetooth specifications? And what example they recommend in order to

implement such a scenario.

Thank you for all your attention,

Best regards

[run_ar]

Hi,

It is not possible for a device to be in deep sleep and wake on packet reception. The BLE protocol uses a timer to wake up when there is a connection event. The connection interval is decided by the master, but it can be negotiated by the slave. The interval has to be somewhere in the 7.5ms to 4s range, but it is possible to configure slave latency which means the slave does not wake up to receive a packet during the configured latency time.

Using a timer to wake up is a very power efficient solution, you can use our online power profiler to calculate the power consumption for different scenarios:https://devzone.nordicsemi.com/nordic/power/

[astella]

Thank you for your kindness. I see. As you say in 'It is not possible for a device to be in deep sleep and wake on packet reception' I can understand that to be able to receive, antenna must be in the proper state. and its consumption about 5-6 mAmps.