SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

hmolesworth — Tue, 05 May 2026 17:36:22 GMT

You might find this code useful on ascertaining pending interrupts: how-do-i-read-the-event-register

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Håkon Alseth — Tue, 05 May 2026 08:48:39 GMT

Please look at the samples that I shared with you for an event/ISR based approach.

The reason why you are seeing a higher consumption is because you are polling every 100 ms:

[quote userid="151276" url="~/f/nordic-q-a/128017/system-on-sleep-wake-up-on-gpio-interrupt-and-timer/565866"]k_msleep(100);[/quote]

Kind regards,

Håkon

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Dinna — Tue, 05 May 2026 08:02:34 GMT

Hello,

Yes, As you suggested, I tried to use k_timer related functions alone, and the _WFI related issues are not seen anymore.

But, earlier, my device was running on 3uA during sleep(in _WFI).
But after making these changes, the device is taking 6.2uA in sleep. Which is not acceptable, as this is a low power device.

#define WAKEUP_PIN 17 /

K_TIMER_DEFINE(my_timer, NULL, NULL);

#define SLEEP_TIME K_SECONDS(600)

#define SLEEP_TIMER_START k_timer_start(&my_timer, SLEEP_TIME, K_NO_WAIT)

#define SLEEP_TIMER_STOP k_timer_stop(&my_timer)

void handle_sleep(void)

{

char woke_from_gpio = 0;

nrf_gpio_cfg_sense_input(WAKEUP_PIN, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW);

SLEEP_TIMER_START; // Start the sleep timer

pm_state_force(0u,&(struct pm_state_info){PM_STATE_SUSPEND_TO_IDLE, 0, 0});

while(1)

{

if (k_timer_remaining_get(&my_timer) == 0) {

break;

}

if (nrf_gpio_pin_read(WAKEUP_PIN) == 0)

{

woke_from_gpio = 1;

break;

}

k_msleep(100);

}

SLEEP_TIMER_STOP;

if(woke_from_gpio == 1)

{

f.g_Panic_sense_F = 1;

woke_from_gpio=0;

}

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Håkon Alseth — Tue, 05 May 2026 07:08:52 GMT

Hi,

[quote user="Dinna"]

Do you have any suggestions on how to use SYSTEM ON sleep, with wake up on both timer expiry and GPIO interrupt generation. [/quote]

Check out the zephyr/samples/basic/button sample.

Try to combine this with a k_timer instance:

https://docs.zephyrproject.org/latest/kernel/services/timing/timers.html#using-a-timer-expiry-function

Kind regards,

Håkon

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Dinna — Tue, 05 May 2026 06:59:15 GMT

Hello,

[quote userid="2115" url="~/f/nordic-q-a/128017/system-on-sleep-wake-up-on-gpio-interrupt-and-timer/565855"]You need to check if your wanted condition (ie. your interrupt) has occurred.[/quote]

This is where the issue is, the device wakes up before the actual interrupt should occur, i.e., exactly 5 minutes or exactly 10 minutes.
The device wakes up before these conditions are met.

Do you have any suggestions on how to use SYSTEM ON sleep, with wake up on both timer expiry and GPIO interrupt generation.

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Håkon Alseth — Tue, 05 May 2026 06:49:29 GMT

Hi,

[quote user="Dinna"]Also please let me know if there is a way to know what interrupt was received from WFI.[/quote]

There is no specific register to read. You need to check if your wanted condition (ie. your interrupt) has occurred.

[quote user="Dinna"]

Then, I tried to print the values of the ticks using this method, so i can spot the overflow at 4.5 minutes.

But it seemed to work fine here.

[/quote]

The driver handles the overflow, but the nRF will generate a wake up condition.

k_cpu_idle is a wrapper for __WFI(), while k_sleep() is a sleep function with a specific timeout parameter.

Kind regards,

Håkon

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Dinna — Tue, 05 May 2026 05:41:23 GMT

Hello Hakon,
Thankyou for the response.

I tried to use k_cpu_idle() instead of WFI . But the same behaviour is seen.
After 4.5 minutes the device woke up again just like WFI.

I tried another configuration as well :
in prj.conf file:

CONFIG_TIMEOUT_64BIT=y

CONFIG_SYS_CLOCK_TICKS_PER_SEC=1024

Then, I tried to print the values of the ticks using this method, so i can spot the overflow at 4.5 minutes.

But it seemed to work fine here.

#define SLEEP_TIME K_SECONDS(300) // Define sleep time as 10 seconds

#define SLEEP_TIMER_START k_timer_start(&my_timer, SLEEP_TIME, K_NO_WAIT)

void handle_sleep(void)

{

uint64_t start_ticks = k_uptime_ticks();

SLEEP_TIMER_START;

while (1)

{

int64_t now = k_uptime_ticks();

printk("Elapsed ticks = %lld\n", (now - start_ticks));

printk("k_timer_remaining_get(&my_timer) = %u\r\n =========\r\n",k_timer_remaining_get(&my_timer));

k_sleep(K_SECONDS(1));

}

}

LOGS :

*** Booting Zephyr OS build v3.2.99-ncs2 ***
ENTER MAIN function
Elapsed ticks = 0
k_timer_remaining_get(&my_timer) = 300000
=========
Elapsed ticks = 1026
k_timer_remaining_get(&my_timer) = 298998
=========
Elapsed ticks = 2052
k_timer_remaining_get(&my_timer) = 297996
=========
Elapsed ticks = 3078
k_timer_remaining_get(&my_timer) = 296994
=========
Elapsed ticks = 4104
k_timer_remaining_get(&my_timer) = 295992
=========
Elapsed ticks = 5130
k_timer_remaining_get(&my_timer) = 294990
=========
Elapsed ticks = 6156
k_timer_remaining_get(&my_timer) = 293988
=========
Elapsed ticks = 7182
k_timer_remaining_get(&my_timer) = 292986
=========
Elapsed ticks = 8208
k_timer_remaining_get(&my_timer) = 291984
=========
Elapsed ticks = 9234
k_timer_remaining_get(&my_timer) = 290982
=========
Elapsed ticks = 10260
k_timer_remaining_get(&my_timer) = 289980
=========
Elapsed ticks = 11286
k_timer_remaining_get(&my_timer) = 288978
=========
Elapsed ticks = 12312
k_timer_remaining_get(&my_timer) = 287976
=========
Elapsed ticks = 13338
k_timer_remaining_get(&my_timer) = 286974
=========
Elapsed ticks = 14364
k_timer_remaining_get(&my_timer) = 285972
=========
Elapsed ticks = 15390
k_timer_remaining_get(&my_timer) = 284970
=========
Elapsed ticks = 16416
k_timer_remaining_get(&my_timer) = 283968
=========
Elapsed ticks = 17442
k_timer_remaining_get(&my_timer) = 282966
=========
Elapsed ticks = 18468
k_timer_remaining_get(&my_timer) = 281964
=========
Elapsed ticks = 19494
k_timer_remaining_get(&my_timer) = 280962
=========
Elapsed ticks = 20520
k_timer_remaining_get(&my_timer) = 279960
=========
Elapsed ticks = 21546
k_timer_remaining_get(&my_timer) = 278958
=========
Elapsed ticks = 22572
k_timer_remaining_get(&my_timer) = 277957
=========
Elapsed ticks = 23598
k_timer_remaining_get(&my_timer) = 276955
=========
Elapsed ticks = 24624
k_timer_remaining_get(&my_timer) = 275953
=========
Elapsed ticks = 25650
k_timer_remaining_get(&my_timer) = 274951
=========
Elapsed ticks = 26676
k_timer_remaining_get(&my_timer) = 273949
=========
Elapsed ticks = 27702
k_timer_remaining_get(&my_timer) = 272947
=========
Elapsed ticks = 28728
k_timer_remaining_get(&my_timer) = 271945
=========
Elapsed ticks = 29754
k_timer_remaining_get(&my_timer) = 270943
=========
Elapsed ticks = 30780
k_timer_remaining_get(&my_timer) = 269941
=========
Elapsed ticks = 31806
k_timer_remaining_get(&my_timer) = 268939
=========
Elapsed ticks = 32832
k_timer_remaining_get(&my_timer) = 267937
=========
Elapsed ticks = 33858
k_timer_remaining_get(&my_timer) = 266935
=========
Elapsed ticks = 34884
k_timer_remaining_get(&my_timer) = 265933
=========
Elapsed ticks = 35910
k_timer_remaining_get(&my_timer) = 264931
=========
Elapsed ticks = 36936
k_timer_remaining_get(&my_timer) = 263929
=========
Elapsed ticks = 37962
k_timer_remaining_get(&my_timer) = 262927
=========
Elapsed ticks = 38988
k_timer_remaining_get(&my_timer) = 261925
=========
Elapsed ticks = 40014
k_timer_remaining_get(&my_timer) = 260923
=========
Elapsed ticks = 41040
k_timer_remaining_get(&my_timer) = 259921
=========
Elapsed ticks = 42066
k_timer_remaining_get(&my_timer) = 258919
=========
Elapsed ticks = 43092
k_timer_remaining_get(&my_timer) = 257917
=========
Elapsed ticks = 44118
k_timer_remaining_get(&my_timer) = 256916
=========
Elapsed ticks = 45144
k_timer_remaining_get(&my_timer) = 255914
=========
Elapsed ticks = 46170
k_timer_remaining_get(&my_timer) = 254912
=========
Elapsed ticks = 47196
k_timer_remaining_get(&my_timer) = 253910
=========
Elapsed ticks = 48222
k_timer_remaining_get(&my_timer) = 252908
=========
Elapsed ticks = 49248
k_timer_remaining_get(&my_timer) = 251906
=========
Elapsed ticks = 50274
k_timer_remaining_get(&my_timer) = 250904
=========
Elapsed ticks = 51300
k_timer_remaining_get(&my_timer) = 249902
=========
Elapsed ticks = 52326
k_timer_remaining_get(&my_timer) = 248900
=========
Elapsed ticks = 53352
k_timer_remaining_get(&my_timer) = 247898
=========
Elapsed ticks = 54378
k_timer_remaining_get(&my_timer) = 246896
=========
Elapsed ticks = 55404
k_timer_remaining_get(&my_timer) = 245894
=========
Elapsed ticks = 56430
k_timer_remaining_get(&my_timer) = 244892
=========
Elapsed ticks = 57456
k_timer_remaining_get(&my_timer) = 243890
=========
Elapsed ticks = 58482
k_timer_remaining_get(&my_timer) = 242888
=========
Elapsed ticks = 59508
k_timer_remaining_get(&my_timer) = 241886
=========
Elapsed ticks = 60534
k_timer_remaining_get(&my_timer) = 240884
=========
Elapsed ticks = 61560
k_timer_remaining_get(&my_timer) = 239882
=========
Elapsed ticks = 62586
k_timer_remaining_get(&my_timer) = 238880
=========
Elapsed ticks = 63612
k_timer_remaining_get(&my_timer) = 237878
=========
Elapsed ticks = 64638
k_timer_remaining_get(&my_timer) = 236876
=========
Elapsed ticks = 65664
k_timer_remaining_get(&my_timer) = 235875
=========
Elapsed ticks = 66690
k_timer_remaining_get(&my_timer) = 234873
=========
Elapsed ticks = 67716
k_timer_remaining_get(&my_timer) = 233871
=========
Elapsed ticks = 68742
k_timer_remaining_get(&my_timer) = 232869
=========
Elapsed ticks = 69768
k_timer_remaining_get(&my_timer) = 231867
=========
Elapsed ticks = 70794
k_timer_remaining_get(&my_timer) = 230865
=========
Elapsed ticks = 71820
k_timer_remaining_get(&my_timer) = 229863
=========
Elapsed ticks = 72846
k_timer_remaining_get(&my_timer) = 228861
=========
Elapsed ticks = 73872
k_timer_remaining_get(&my_timer) = 227859
=========
Elapsed ticks = 74898
k_timer_remaining_get(&my_timer) = 226857
=========
Elapsed ticks = 75924
k_timer_remaining_get(&my_timer) = 225855
=========
Elapsed ticks = 76950
k_timer_remaining_get(&my_timer) = 224853
=========
Elapsed ticks = 77976
k_timer_remaining_get(&my_timer) = 223851
=========
Elapsed ticks = 79002
k_timer_remaining_get(&my_timer) = 222849
=========
Elapsed ticks = 80028
k_timer_remaining_get(&my_timer) = 221847
=========
Elapsed ticks = 81054
k_timer_remaining_get(&my_timer) = 220845
=========
Elapsed ticks = 82080
k_timer_remaining_get(&my_timer) = 219843
=========
Elapsed ticks = 83106
k_timer_remaining_get(&my_timer) = 218841
=========
Elapsed ticks = 84132
k_timer_remaining_get(&my_timer) = 217839
=========
Elapsed ticks = 85158
k_timer_remaining_get(&my_timer) = 216837
=========
Elapsed ticks = 86184
k_timer_remaining_get(&my_timer) = 215835
=========
Elapsed ticks = 87210
k_timer_remaining_get(&my_timer) = 214833
=========
Elapsed ticks = 88236
k_timer_remaining_get(&my_timer) = 213832
=========
Elapsed ticks = 89262
k_timer_remaining_get(&my_timer) = 212830
=========
Elapsed ticks = 90288
k_timer_remaining_get(&my_timer) = 211828
=========
Elapsed ticks = 91314
k_timer_remaining_get(&my_timer) = 210826
=========
Elapsed ticks = 92340
k_timer_remaining_get(&my_timer) = 209824
=========
Elapsed ticks = 93366
k_timer_remaining_get(&my_timer) = 208822
=========
Elapsed ticks = 94392
k_timer_remaining_get(&my_timer) = 207820
=========
Elapsed ticks = 95418
k_timer_remaining_get(&my_timer) = 206818
=========
Elapsed ticks = 96444
k_timer_remaining_get(&my_timer) = 205816
=========
Elapsed ticks = 97470
k_timer_remaining_get(&my_timer) = 204814
=========
Elapsed ticks = 98496
k_timer_remaining_get(&my_timer) = 203812
=========
Elapsed ticks = 99522
k_timer_remaining_get(&my_timer) = 202810
=========
Elapsed ticks = 100548
k_timer_remaining_get(&my_timer) = 201808
=========
Elapsed ticks = 101574
k_timer_remaining_get(&my_timer) = 200806
=========
Elapsed ticks = 102600
k_timer_remaining_get(&my_timer) = 199804
=========
Elapsed ticks = 103626
k_timer_remaining_get(&my_timer) = 198802
=========
Elapsed ticks = 104652
k_timer_remaining_get(&my_timer) = 197800
=========
Elapsed ticks = 105678
k_timer_remaining_get(&my_timer) = 196798
=========
Elapsed ticks = 106704
k_timer_remaining_get(&my_timer) = 195796
=========
Elapsed ticks = 107730
k_timer_remaining_get(&my_timer) = 194794
=========
Elapsed ticks = 108756
k_timer_remaining_get(&my_timer) = 193792
=========
Elapsed ticks = 109782
k_timer_remaining_get(&my_timer) = 192791
=========
Elapsed ticks = 110808
k_timer_remaining_get(&my_timer) = 191789
=========
Elapsed ticks = 111834
k_timer_remaining_get(&my_timer) = 190787
=========
Elapsed ticks = 112860
k_timer_remaining_get(&my_timer) = 189785
=========
Elapsed ticks = 113886
k_timer_remaining_get(&my_timer) = 188783
=========
Elapsed ticks = 114912
k_timer_remaining_get(&my_timer) = 187781
=========
Elapsed ticks = 115938
k_timer_remaining_get(&my_timer) = 186779
=========
Elapsed ticks = 116964
k_timer_remaining_get(&my_timer) = 185777
=========
Elapsed ticks = 117990
k_timer_remaining_get(&my_timer) = 184775
=========
Elapsed ticks = 119016
k_timer_remaining_get(&my_timer) = 183773
=========
Elapsed ticks = 120042
k_timer_remaining_get(&my_timer) = 182771
=========
Elapsed ticks = 121068
k_timer_remaining_get(&my_timer) = 181769
=========
Elapsed ticks = 122094
k_timer_remaining_get(&my_timer) = 180767
=========
Elapsed ticks = 123120
k_timer_remaining_get(&my_timer) = 179765
=========
Elapsed ticks = 124146
k_timer_remaining_get(&my_timer) = 178763
=========
Elapsed ticks = 125172
k_timer_remaining_get(&my_timer) = 177761
=========
Elapsed ticks = 126198
k_timer_remaining_get(&my_timer) = 176759
=========
Elapsed ticks = 127224
k_timer_remaining_get(&my_timer) = 175757
=========
Elapsed ticks = 128250
k_timer_remaining_get(&my_timer) = 174755
=========
Elapsed ticks = 129276
k_timer_remaining_get(&my_timer) = 173753
=========
Elapsed ticks = 130302
k_timer_remaining_get(&my_timer) = 172751
=========
Elapsed ticks = 131328
k_timer_remaining_get(&my_timer) = 171750
=========
Elapsed ticks = 132354
k_timer_remaining_get(&my_timer) = 170748
=========
Elapsed ticks = 133380
k_timer_remaining_get(&my_timer) = 169746
=========
Elapsed ticks = 134406
k_timer_remaining_get(&my_timer) = 168744
=========
Elapsed ticks = 135432
k_timer_remaining_get(&my_timer) = 167742
=========
Elapsed ticks = 136458
k_timer_remaining_get(&my_timer) = 166740
=========
Elapsed ticks = 137484
k_timer_remaining_get(&my_timer) = 165738
=========
Elapsed ticks = 138510
k_timer_remaining_get(&my_timer) = 164736
=========
Elapsed ticks = 139536
k_timer_remaining_get(&my_timer) = 163734
=========
Elapsed ticks = 140562
k_timer_remaining_get(&my_timer) = 162732
=========
Elapsed ticks = 141588
k_timer_remaining_get(&my_timer) = 161730
=========
Elapsed ticks = 142614
k_timer_remaining_get(&my_timer) = 160728
=========
Elapsed ticks = 143640
k_timer_remaining_get(&my_timer) = 159726
=========
Elapsed ticks = 144666
k_timer_remaining_get(&my_timer) = 158724
=========
Elapsed ticks = 145692
k_timer_remaining_get(&my_timer) = 157722
=========
Elapsed ticks = 146718
k_timer_remaining_get(&my_timer) = 156720
=========
Elapsed ticks = 147744
k_timer_remaining_get(&my_timer) = 155718
=========
Elapsed ticks = 148770
k_timer_remaining_get(&my_timer) = 154716
=========
Elapsed ticks = 149796
k_timer_remaining_get(&my_timer) = 153714
=========
Elapsed ticks = 150822
k_timer_remaining_get(&my_timer) = 152712
=========
Elapsed ticks = 151848
k_timer_remaining_get(&my_timer) = 151710
=========
Elapsed ticks = 152874
k_timer_remaining_get(&my_timer) = 150708
=========
Elapsed ticks = 153900
k_timer_remaining_get(&my_timer) = 149707
=========
Elapsed ticks = 154926
k_timer_remaining_get(&my_timer) = 148705
=========
Elapsed ticks = 155952
k_timer_remaining_get(&my_timer) = 147703
=========
Elapsed ticks = 156978
k_timer_remaining_get(&my_timer) = 146701
=========
Elapsed ticks = 158004
k_timer_remaining_get(&my_timer) = 145699
=========
Elapsed ticks = 159030
k_timer_remaining_get(&my_timer) = 144697
=========
Elapsed ticks = 160056
k_timer_remaining_get(&my_timer) = 143695
=========
Elapsed ticks = 161082
k_timer_remaining_get(&my_timer) = 142693
=========
Elapsed ticks = 162108
k_timer_remaining_get(&my_timer) = 141691
=========
Elapsed ticks = 163134
k_timer_remaining_get(&my_timer) = 140689
=========
Elapsed ticks = 164160
k_timer_remaining_get(&my_timer) = 139687
=========
Elapsed ticks = 165186
k_timer_remaining_get(&my_timer) = 138685
=========
Elapsed ticks = 166212
k_timer_remaining_get(&my_timer) = 137683
=========
Elapsed ticks = 167238
k_timer_remaining_get(&my_timer) = 136681
=========
Elapsed ticks = 168264
k_timer_remaining_get(&my_timer) = 135679
=========
Elapsed ticks = 169290
k_timer_remaining_get(&my_timer) = 134677
=========
Elapsed ticks = 170316
k_timer_remaining_get(&my_timer) = 133675
=========
Elapsed ticks = 171342
k_timer_remaining_get(&my_timer) = 132673
=========
Elapsed ticks = 172368
k_timer_remaining_get(&my_timer) = 131671
=========
Elapsed ticks = 173394
k_timer_remaining_get(&my_timer) = 130669
=========
Elapsed ticks = 174420
k_timer_remaining_get(&my_timer) = 129667
=========
Elapsed ticks = 175446
k_timer_remaining_get(&my_timer) = 128666
=========
Elapsed ticks = 176472
k_timer_remaining_get(&my_timer) = 127664
=========
Elapsed ticks = 177498
k_timer_remaining_get(&my_timer) = 126662
=========
Elapsed ticks = 178524
k_timer_remaining_get(&my_timer) = 125660
=========
Elapsed ticks = 179550
k_timer_remaining_get(&my_timer) = 124658
=========
Elapsed ticks = 180576
k_timer_remaining_get(&my_timer) = 123656
=========
Elapsed ticks = 181602
k_timer_remaining_get(&my_timer) = 122654
=========
Elapsed ticks = 182628
k_timer_remaining_get(&my_timer) = 121652
=========
Elapsed ticks = 183654
k_timer_remaining_get(&my_timer) = 120650
=========
Elapsed ticks = 184680
k_timer_remaining_get(&my_timer) = 119648
=========
Elapsed ticks = 185706
k_timer_remaining_get(&my_timer) = 118646
=========
Elapsed ticks = 186732
k_timer_remaining_get(&my_timer) = 117644
=========
Elapsed ticks = 187758
k_timer_remaining_get(&my_timer) = 116642
=========
Elapsed ticks = 188784
k_timer_remaining_get(&my_timer) = 115640
=========
Elapsed ticks = 189810
k_timer_remaining_get(&my_timer) = 114638
=========
Elapsed ticks = 190836
k_timer_remaining_get(&my_timer) = 113636
=========
Elapsed ticks = 191862
k_timer_remaining_get(&my_timer) = 112634
=========
Elapsed ticks = 192888
k_timer_remaining_get(&my_timer) = 111632
=========
Elapsed ticks = 193914
k_timer_remaining_get(&my_timer) = 110630
=========
Elapsed ticks = 194940
k_timer_remaining_get(&my_timer) = 109628
=========
Elapsed ticks = 195966
k_timer_remaining_get(&my_timer) = 108626
=========
Elapsed ticks = 196992
k_timer_remaining_get(&my_timer) = 107625
=========
Elapsed ticks = 198018
k_timer_remaining_get(&my_timer) = 106623
=========
Elapsed ticks = 199044
k_timer_remaining_get(&my_timer) = 105621
=========
Elapsed ticks = 200070
k_timer_remaining_get(&my_timer) = 104619
=========
Elapsed ticks = 201096
k_timer_remaining_get(&my_timer) = 103617
=========
Elapsed ticks = 202122
k_timer_remaining_get(&my_timer) = 102615
=========
Elapsed ticks = 203148
k_timer_remaining_get(&my_timer) = 101613
=========
Elapsed ticks = 204174
k_timer_remaining_get(&my_timer) = 100611
=========
Elapsed ticks = 205200
k_timer_remaining_get(&my_timer) = 99609
=========
Elapsed ticks = 206226
k_timer_remaining_get(&my_timer) = 98607
=========
Elapsed ticks = 207252
k_timer_remaining_get(&my_timer) = 97605
=========
Elapsed ticks = 208278
k_timer_remaining_get(&my_timer) = 96603
=========
Elapsed ticks = 209304
k_timer_remaining_get(&my_timer) = 95601
=========
Elapsed ticks = 210330
k_timer_remaining_get(&my_timer) = 94599
=========
Elapsed ticks = 211356
k_timer_remaining_get(&my_timer) = 93597
=========
Elapsed ticks = 212382
k_timer_remaining_get(&my_timer) = 92595
=========
Elapsed ticks = 213408
k_timer_remaining_get(&my_timer) = 91593
=========
Elapsed ticks = 214434
k_timer_remaining_get(&my_timer) = 90591
=========
Elapsed ticks = 215460
k_timer_remaining_get(&my_timer) = 89589
=========
Elapsed ticks = 216486
k_timer_remaining_get(&my_timer) = 88587
=========
Elapsed ticks = 217512
k_timer_remaining_get(&my_timer) = 87585
=========
Elapsed ticks = 218538
k_timer_remaining_get(&my_timer) = 86583
=========
Elapsed ticks = 219564
k_timer_remaining_get(&my_timer) = 85582
=========
Elapsed ticks = 220590
k_timer_remaining_get(&my_timer) = 84580
=========
Elapsed ticks = 221616
k_timer_remaining_get(&my_timer) = 83578
=========
Elapsed ticks = 222642
k_timer_remaining_get(&my_timer) = 82576
=========
Elapsed ticks = 223668
k_timer_remaining_get(&my_timer) = 81574
=========
Elapsed ticks = 224694
k_timer_remaining_get(&my_timer) = 80572
=========
Elapsed ticks = 225720
k_timer_remaining_get(&my_timer) = 79570
=========
Elapsed ticks = 226746
k_timer_remaining_get(&my_timer) = 78568
=========
Elapsed ticks = 227772
k_timer_remaining_get(&my_timer) = 77566
=========
Elapsed ticks = 228798
k_timer_remaining_get(&my_timer) = 76564
=========
Elapsed ticks = 229824
k_timer_remaining_get(&my_timer) = 75562
=========
Elapsed ticks = 230850
k_timer_remaining_get(&my_timer) = 74560
=========
Elapsed ticks = 231876
k_timer_remaining_get(&my_timer) = 73558
=========
Elapsed ticks = 232902
k_timer_remaining_get(&my_timer) = 72556
=========
Elapsed ticks = 233928
k_timer_remaining_get(&my_timer) = 71554
=========
Elapsed ticks = 234954
k_timer_remaining_get(&my_timer) = 70552
=========
Elapsed ticks = 235980
k_timer_remaining_get(&my_timer) = 69550
=========
Elapsed ticks = 237006
k_timer_remaining_get(&my_timer) = 68548
=========
Elapsed ticks = 238032
k_timer_remaining_get(&my_timer) = 67546
=========
Elapsed ticks = 239058
k_timer_remaining_get(&my_timer) = 66544
=========
Elapsed ticks = 240084
k_timer_remaining_get(&my_timer) = 65542
=========
Elapsed ticks = 241110
k_timer_remaining_get(&my_timer) = 64541
=========
Elapsed ticks = 242136
k_timer_remaining_get(&my_timer) = 63539
=========
Elapsed ticks = 243162
k_timer_remaining_get(&my_timer) = 62537
=========
Elapsed ticks = 244188
k_timer_remaining_get(&my_timer) = 61535
=========
Elapsed ticks = 245214
k_timer_remaining_get(&my_timer) = 60533
=========
Elapsed ticks = 246240
k_timer_remaining_get(&my_timer) = 59531
=========
Elapsed ticks = 247266
k_timer_remaining_get(&my_timer) = 58529
=========
Elapsed ticks = 248292
k_timer_remaining_get(&my_timer) = 57527
=========
Elapsed ticks = 249318
k_timer_remaining_get(&my_timer) = 56525
=========
Elapsed ticks = 250344
k_timer_remaining_get(&my_timer) = 55523
=========
Elapsed ticks = 251370
k_timer_remaining_get(&my_timer) = 54521
=========
Elapsed ticks = 252396
k_timer_remaining_get(&my_timer) = 53519
=========
Elapsed ticks = 253422
k_timer_remaining_get(&my_timer) = 52517
=========
Elapsed ticks = 254448
k_timer_remaining_get(&my_timer) = 51515
=========
Elapsed ticks = 255474
k_timer_remaining_get(&my_timer) = 50513
=========
Elapsed ticks = 256500
k_timer_remaining_get(&my_timer) = 49511
=========
Elapsed ticks = 257526
k_timer_remaining_get(&my_timer) = 48509
=========
Elapsed ticks = 258552
k_timer_remaining_get(&my_timer) = 47507
=========
Elapsed ticks = 259578
k_timer_remaining_get(&my_timer) = 46505
=========
Elapsed ticks = 260604
k_timer_remaining_get(&my_timer) = 45503
=========
Elapsed ticks = 261630
k_timer_remaining_get(&my_timer) = 44501
=========
Elapsed ticks = 262656
k_timer_remaining_get(&my_timer) = 43500
=========
Elapsed ticks = 263682
k_timer_remaining_get(&my_timer) = 42498
=========
Elapsed ticks = 264708
k_timer_remaining_get(&my_timer) = 41496
=========
Elapsed ticks = 265734
k_timer_remaining_get(&my_timer) = 40494
=========
Elapsed ticks = 266760
k_timer_remaining_get(&my_timer) = 39492
=========
Elapsed ticks = 267786
k_timer_remaining_get(&my_timer) = 38490
=========
Elapsed ticks = 268812
k_timer_remaining_get(&my_timer) = 37488
=========
Elapsed ticks = 269838
k_timer_remaining_get(&my_timer) = 36486
=========
Elapsed ticks = 270864
k_timer_remaining_get(&my_timer) = 35484
=========
Elapsed ticks = 271890
k_timer_remaining_get(&my_timer) = 34482
=========
Elapsed ticks = 272916
k_timer_remaining_get(&my_timer) = 33480
=========
Elapsed ticks = 273942
k_timer_remaining_get(&my_timer) = 32478
=========
Elapsed ticks = 274968
k_timer_remaining_get(&my_timer) = 31476
=========
Elapsed ticks = 275994
k_timer_remaining_get(&my_timer) = 30474
=========
Elapsed ticks = 277020
k_timer_remaining_get(&my_timer) = 29472
=========
Elapsed ticks = 278046
k_timer_remaining_get(&my_timer) = 28470
=========
Elapsed ticks = 279072
k_timer_remaining_get(&my_timer) = 27468
=========
Elapsed ticks = 280098
k_timer_remaining_get(&my_timer) = 26466
=========
Elapsed ticks = 281124
k_timer_remaining_get(&my_timer) = 25464
=========
Elapsed ticks = 282150
k_timer_remaining_get(&my_timer) = 24462
=========
Elapsed ticks = 283176
k_timer_remaining_get(&my_timer) = 23460
=========
Elapsed ticks = 284202
k_timer_remaining_get(&my_timer) = 22458
=========
Elapsed ticks = 285228
k_timer_remaining_get(&my_timer) = 21457
=========
Elapsed ticks = 286254
k_timer_remaining_get(&my_timer) = 20455
=========
Elapsed ticks = 287280
k_timer_remaining_get(&my_timer) = 19453
=========
Elapsed ticks = 288306
k_timer_remaining_get(&my_timer) = 18451
=========
Elapsed ticks = 289332
k_timer_remaining_get(&my_timer) = 17449
=========
Elapsed ticks = 290358
k_timer_remaining_get(&my_timer) = 16447
=========
Elapsed ticks = 291384
k_timer_remaining_get(&my_timer) = 15445
=========
Elapsed ticks = 292410
k_timer_remaining_get(&my_timer) = 14443
=========
Elapsed ticks = 293436
k_timer_remaining_get(&my_timer) = 13441
=========
Elapsed ticks = 294462
k_timer_remaining_get(&my_timer) = 12439
=========
Elapsed ticks = 295488
k_timer_remaining_get(&my_timer) = 11437
=========
Elapsed ticks = 296514
k_timer_remaining_get(&my_timer) = 10435
=========
Elapsed ticks = 297540
k_timer_remaining_get(&my_timer) = 9433
=========
Elapsed ticks = 298566
k_timer_remaining_get(&my_timer) = 8431
=========
Elapsed ticks = 299592
k_timer_remaining_get(&my_timer) = 7429
=========
Elapsed ticks = 300618
k_timer_remaining_get(&my_timer) = 6427
=========
Elapsed ticks = 301644
k_timer_remaining_get(&my_timer) = 5425
=========
Elapsed ticks = 302670
k_timer_remaining_get(&my_timer) = 4423
=========
Elapsed ticks = 303696
k_timer_remaining_get(&my_timer) = 3421
=========
Elapsed ticks = 304722
k_timer_remaining_get(&my_timer) = 2419
=========
Elapsed ticks = 305748
k_timer_remaining_get(&my_timer) = 1417
=========
Elapsed ticks = 306774
k_timer_remaining_get(&my_timer) = 416
=========
Elapsed ticks = 307799
k_timer_remaining_get(&my_timer) = 0
=========
Elapsed ticks = 308825
k_timer_remaining_get(&my_timer) = 0
=========

Also please let me know if there is a way to know what interrupt was received from WFI.

RE: SYSTEM ON SLEEP : Wake up on gpio interrupt and Timer

Håkon Alseth — Mon, 04 May 2026 14:33:53 GMT

Hi,

the RTC rolls over at 512 seconds (24^2 * 1/32768), but the kernel timer driver wraps around at half of it, to avoid a corner case:

https://github.com/zephyrproject-rtos/zephyr/blob/main/drivers/timer/nrf_rtc_timer.c#L690-L694

255 seconds = 4.25 minutes, which is similar to what you're observing.

"WFI" waits for any interrupt and wakes up. In a RTOS, these can be internal to the OS, so I would recommend that you use k_cpu_idle() (https://docs.zephyrproject.org/latest/doxygen/html/group__cpu__idle__apis.html) instead.

Kind regards,

Håkon