topic KW36 LOWPOWER in Wireless MCU

KW36 LOWPOWER

wjw2023 — Tue, 29 Apr 2025 05:25:09 GMT

KW36 enter lowpower mode，start low power timer，It was found that the timer was inaccurate .

test_timer = TMR_AllocateTimer();
TMR_StartLowPowerTimer(test_timer , gTmrLowPowerIntervalMillisTimer_c, 1000, set_event, NULL);

Re: KW36 LOWPOWER

luis_maravilla — Wed, 30 Apr 2025 21:29:17 GMT

Hello, Could you help us bring more information please?

What example are you running?

What version of MCUXpresso and SDK are you using?

Are you using the FRDM-KW36 or a custom board?

Do you have any other modifications on your code?

Re: KW36 LOWPOWER

wjw2023 — Wed, 07 May 2025 10:51:46 GMT

sdk ver 2.2.5

example：w_uart

Create a task and implement the following code :

static void set_event(void *param)

{

OSA_EventSet(event, 1);

}

static tmrTimerID_t p_timer = gTmrInvalidTimerID_c;

void test_service()

{

uint32_t count = 0;

osaStatus_t status;

osaEventFlags_t flags = 0;

p_timer = TMR_AllocateTimer();

TMR_StartLowPowerTimer(p_timer, gTmrLowPowerIntervalMillisTimer_c, 200, set_event, NULL);

event = OSA_EventCreate(true);

for (;;) {

status = OSA_EventWait(event, ~0, false, 1000, &flags);

if (status == osaStatus_Success && (flags & 1)) {

if (++count >= 300) {

count = 0;

PWR_DisallowDeviceToSleep();

printf("test.........\n");//1分钟打印一次

PWR_AllowDeviceToSleep();

}

The execution result is shown in the figure. After entering low power consumption, the timing is inaccurate

Re: KW36 LOWPOWER

luis_maravilla — Fri, 09 May 2025 17:11:03 GMT

Hello

I need to confirm if the example w_uart is the bm or the FreeRTOS example.

Best Regards

Luis

Re: KW36 LOWPOWER

wjw2023 — Mon, 12 May 2025 01:52:39 GMT

Hello

FreeRTOS example.

I have provided the source code and operation logs above. Can we conduct analysis based on these?

Re: KW36 LOWPOWER

luis_maravilla — Mon, 12 May 2025 20:30:27 GMT

Hello

When you use FreeRTOS in low power mode for your demo application, Its necessary to check when the next task it is going to change, and set a timer that synchronizes the timer you created as it exits the low power mode, and recover the time and make the call to adjust to the time that was sleep during the Low power mode, this synchronization recovers time from low power use.

Also, I would recommend checking the priority of the task you created to be set appropriately; If other tasks have higher priority the timer task might get delayed.

Best Regards

Luis