Long Press to Wake-up

RE: Long Press to Wake-up

Hung Bui — Tue, 14 Mar 2017 13:47:46 GMT

No you don't need to stop advertising , why ? The device enter systemON mode with CPU when you call sd_app_evt_wait() inside power_manage(). When advertising, the CPU sleeps between the advertising interval, same applies when in connection, CPU sleeps most of the time, only wake up by a timer to do BLE tasks.

RE: Long Press to Wake-up

sara — Tue, 14 Mar 2017 09:55:24 GMT

Hi, Does it mean I just need to stop advertising (if using beacon sample project) then the device will enter the systemON mode with CPU off? Thanks again.

RE: Long Press to Wake-up

Hung Bui — Tue, 14 Mar 2017 08:30:28 GMT

You can simply put the CPU to sleep, by calling __WFE function. Please have refer to the main while loop in our rtc example in \examples\peripheral\rtc or if you use Softdevice, please use power_manage() function as in the main loop of our ble examples.

RE: Long Press to Wake-up

sara — Tue, 14 Mar 2017 07:35:05 GMT

Hello Hung Bui, I got it, but how to let the system in system ON mode but CPU off? Thanks.

Sara

RE: Long Press to Wake-up

Hung Bui — Mon, 13 Mar 2017 10:14:29 GMT

@Sara: as endnode wrote, you don't have any timer when you are in SystemOFF so the chip won't know if it's a long press or not. But if you put the systemON mode with CPU off, you can still keep the RTC running and detect if it's a long press or not. SystemON+ RTC running may cost you some uA extra, should be less than 5uA as far as I recall.

RE: Long Press to Wake-up

sara — Mon, 13 Mar 2017 10:03:17 GMT

Understood, thanks for your help.

RE: Long Press to Wake-up

endnode — Mon, 13 Mar 2017 07:20:30 GMT

Hello Sara,

If you mean SYSTEM OFF by your "sleep" then NO, the only wake-up mechanism in your situation is simple GPIOTE level change, there is no clock running in SYSTEM OFF so obviously you cannot detect "long" press. If you need it for user experience then you can of course fake it by going back to OFF mode if the GPIO line doesn't hold "pressed" state long enough after nRF5x wakes up.

CHeers Jan