Wake up from power-off mode

RE: Wake up from power-off mode

Susheel Nuguru — Tue, 04 Aug 2015 11:46:55 GMT

We have noticed that you are not waiting for EVENTS_READY, this could be a problem if you go to system off before the LPCOMP is ready.

So you have to add this

NRF_LPCOMP->TASKS_START = 1;
while(NRF_LPCOMP->EVENTS_READY == 0);
NRF_LPCOMP->EVENTS_READY = 0;

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Fri, 31 Jul 2015 07:37:31 GMT

what I did I noticed that the AIN0 in the datasheet is connected to an external crystal in the development kit, so it didn't work with me with any sleep mode, I changed the pin to AIN4 which is float by default & tried to use it, it works fine with me & with the ble also, I used sd_power_off() and it works with me

RE: Wake up from power-off mode

Susheel Nuguru — Fri, 31 Jul 2015 05:24:38 GMT

Hi mohamed,

on the pca100028 Rev3 kit, i did not manage to get SystemOff work with LPCOMP. Like I said, there is something wierd about it. I do not have the revision of hardware you mentioned, and I am surprised it works for you. Can you tell us what change you made that the SystemOff started working without BLE ?

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 20:38:05 GMT

Aryan, I have a question the power off using SYSTEM_OFF mode, it works with when I use the application only without softdevice or any ble module, when I integrate it to the bluetooth module project, I found that it didn't work, I lose the connection and it didn't become on again

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 20:12:43 GMT

it works with me Aryan, thank you for ur great help

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 19:56:48 GMT

my chip number is N51422 QFACA1 1503D & its datasheet said that AIN0 is P0.26

RE: Wake up from power-off mode

Susheel Nuguru — Thu, 30 Jul 2015 18:57:18 GMT

which nersion of hardware are you using?, p0.26 is not connected to Anolog input of LPCOMP. I changed that part while testing your code. Please read the product specification to see where your Analog inputs are connected. I do bot have the code handy but I think VREF is connected to pin 0 and VAnalog 2 is connected to pin 1. Check the pin assignment for your product in the product specification document. I am sure P0.26 is not connected to LPCOMP in anyway. I also used external dynamic voltage output and change the voltage until it crooses the threshold defined in your code. It works fine if you connect the changing voltage to the correct pins.

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 18:48:25 GMT

how did you test my code, I tested it by adding a voltage source to p0.026 and changing this voltage till it cross the threshold but found nothing changed after it !!!

RE: Wake up from power-off mode

Susheel Nuguru — Thu, 30 Jul 2015 16:59:58 GMT

I did not understand your question, what do you mean by output? When the system wakes up from SystemOFF(Deep sleep) there is a reset first, but when the system wakes up from normal sleep (WFE/WFI) there is no reset, and it continues from where it sleeps. when it goes to sleep by WFE(sd_ble_wait_evt), any event or interrupt will wake the system up. If it is an interrupt then the interrupt is serviced first and then then execution returns to the for loop where power_manage is called. If you are asking about power consumption, i do not remember them but the devzone has covered that topic completely, you can browse for it :)

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 16:25:29 GMT

and the sleep mode "not deep sleep" is developed with the WFE & sd_app_wait_evt(), also from where you knew that my code work ,what was the output after the wake up from the sleep mode

RE: Wake up from power-off mode

Susheel Nuguru — Thu, 30 Jul 2015 15:26:28 GMT

yes, but i cannot get it to work. Could be something related to hardware, i am not sure. system off mode is deep sleep mode and consumes least currect (leakage current) while sleep mode is not deep sleep where you can choose to keep selected modules on like RTC,RAM and HFCLK etc

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 15:18:16 GMT

what shall I expect to see when the app is back from the sleep mode, will it start the main function from scratch or what will happen ? ? ?

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 15:06:23 GMT

what is the main difference between them, it's said that on the documentation of the chip that the LP_COMP can wake up the system from the deep sleep mode (power off) !!!

RE: Wake up from power-off mode

Susheel Nuguru — Thu, 30 Jul 2015 14:13:21 GMT

After the fix I showed above I verified that LPCOMP works normally with sleep mode __WFE(). But it does not wake up from SYSTEM_OFF mode. I have created a internal ticket for it. unfortunately most of the people incharge of this component are on vacation, so the response time will be slow. Until then I recommend you to use __WFE or sd_app_evt_wait instead of system_off.

RE: Wake up from power-off mode

Susheel Nuguru — Thu, 30 Jul 2015 13:06:38 GMT

I haven't tried your code but, looking at it seems like you need to change

NRF_LPCOMP->INTENSET = LPCOMP_INTENSET_UP_Enabled;

NRF_LPCOMP->INTENSET   = (LPCOMP_INTENSET_UP_Enabled << LPCOMP_INTENSET_UP_Pos);

RE: Wake up from power-off mode

Mohamed O.Abouzeid — Thu, 30 Jul 2015 09:03:42 GMT

any help please !!!