how to wake up from system off without reseting a variable

[Tarik]

Hi,

On my ble application, I want to keep after wake up reset the previous value of a variable, I tried using sd_power_ramon_set(0x000f000f) to keep on all ram partitions when in system off mode but it didn't worked. is there any way I can do this using RAM, if not how can I do it using the flash memory

Thank you

[Asbjørn]

sd_power_ramon_set() should keep the RAM valid as long as you get a NRF_SUCCESS back from it. How do you detect that it's not retained? What do you use to wake the chip up from SYSTEMOFF?

[Tarik]

I just discovered sd_power_ramon_set() doesn't return NRF_SUCCESS, what can be the cause ? Thank you

[Asbjørn]

Make sure you write to the sd_power_ramon_set() after you have initialized the softdevice. I just tested this by a very simple if in between conn_params_init() and advertising_start() in the ble_app_hrs example.

It returned success and the value of RAMON was set to 0x00030003.

if(sd_power_ramon_set(0x00030003) == NRF_SUCCESS)
		{
		__nop();
		}