Sleep mode and advertising

[Vladimir Plotkin]

I am just starting with NRF51822 (can't even program the BLE example as IAR support is inadequate but that's another story) and trying to figure out power requirements for my project.

From what was said during Tech Tour I gathered that it is possible to use PPI to trigger events and make peripherals to "do things" without core being involved, such as toggling LED, etc.

The question is: is it possible to set system power mode to Off and still have advertising (say, once every seconds) while core is in off state?

As far as my understanding goes, the SoftDevice is just a glorified library with some sort sort of additional hardware support, such as memory partitioning, etc. This means that the core has to be active in order to do the advertising, Is this correct?

And if the code is powered, then will the application run as well or will the entire SoftDevice processing done within ISR thus preventing application from being executed?

In short, I am trying to figure out the worst case power consumption scenario for cases when the device is asleep and just doing periodic advertisements without going into master/slave relationship.

[Ole Morten]

There are quite detailed current consumption graphs given in the SoftDevice Specification, but you need to correlate with the Product Specification to get the numeric values.

For more information on the power modes of the nRF51822, I'd recommend you to have a look at this question.

As you can see from the above, the core will not go to system off in between advertising events, since only GPIO and reset can wake the chip up from this mode, but will go to system on, idle sleep mode. This will normally give a current consumption of ~3 µA in between connection events / advertising events.

If you have problems with IAR, I'd recommend you to post that as a separate question. However, to get IAR project files, you must either take a look at the zip file of the SDK, or make sure to select "Custom installation location" when installing.