connect with master in any time

Question

Hello,guys 
 I have build one application, in which I want to transmit the Image from Mobile BLE to nrf51822 and than after display on display like E-paper. 
 The use case is like 
 
 "In any time The mobile can transmit the image to nrf51822 chip". 
 "The maximum amount of time the chip nrf51822 will be in system off mode". 
 
 now the question is like...
 In which condition the nrf51822 knows the mobile will send the image? 
 are all time the nrf51822 chip in advertising mode? 
 are any switch interrupt is required? 
 Please suggest me
how i can build this type of application? 
 it is good to me if you provide me a this much type of example. 
 Thank You
Milav

endnode · Accepted Answer

Your requirements are contradictory and cannot be fulfilled at the same time. Pretty much everyone must see it. If you want to be able to connect at any time then you need to advertise all the time (and frequency is given by another requirement which you don't list: what is maximum latency you allow for that connection? Note that it typically takes several adv. intervals before Master connects and this is even worse when adv. interval goes above 500ms.). And if you need to advertise all the time then you cannot be in SYSTEM OFF mode. 
 Actually unless you implement external RTC on some low-power chip and that will wake up nRF5x periodically from SYSTEM OFF, it boots, sends one adv. packet and if there is no connection then goes to SYSTEM OFF again. But note that boot procedure has specific power requirements so you will be still far from ideal power consumption which you dream about from SYSTEM OFF number in Product Specification...