TIMER behavior in STM32WLE

[HamadyDIA]

Board : STM32WLE5JB

Software : Move-Xduino . Based on stm32duino 2.3.0

Settings : Arduino 2.0.2 ? , optimise : smallest+LTO

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Hello,

I have an issue with the behavior of the timer with STM32WLE.

I need to have a timer that start every time a specific GPIO is high.

After this i enable a interrupt to an other GPIO and count the numbers of risings eges for 100 ms (timer).

But all of this is managed with the chip on stop mode (mode 2 i think).

And with my code sometimes the interrupt for the rising edge isn't working or the timer can't stop and the chip never goes in stop mode

Here is my code

void CALLBACK_TIM2(){
  detachInterrupt(digitalPinToInterrupt(FREQUENCE_PIN)); 
  digitalWrite(LED_VERT,!digitalRead(LED_VERT)); 
  App_son.frequence_finale=App_son.frequence_int;
  tim2=true;
}

void INIT_TIMER_2(void) {
  TIM_2->setOverflow(10, HERTZ_FORMAT); // 100ms
  TIM_2->attachInterrupt(CALLBACK_TIM2);
  TIM_2->resume();
}

void FREQUENCE_2(){
  App_son.frequence_int++;
  digitalWrite(LED_BLEU,!digitalRead(LED_BLEU));   
}

void SINGAL_SON(void) {
  INIT_TIMER_2();
  TIM_2->setCount(0);
  TIM_2->attachInterrupt(CALLBACK_TIM2);
  TIM_2->resume();
  attachInterrupt(digitalPinToInterrupt(FREQUENCE_PIN), FREQUENCE_2, RISING);
  while(tim2==false){

  }
  
  tim2=false;
  //Serial2.begin(112500);
  //Serial2.println(App_son.frequence_finale);
  App_son.frequence_finale=0;
  App_son.frequence_int=0;
  //TIM_2->pause();
  //onLPEnter();  //Callback when the chip goes in stop mode 
}

Thanks

[ABOSTM]

Hi @HamadyDIA,
Several remarks on your code:

• remove duplicate line from SINGAL_SON() which are already in INIT_TIMER_2()

  TIM_2->attachInterrupt(CALLBACK_TIM2);
  TIM_2->resume();

• move TIM_2->setCount(0); in INIT_TIMER_2()
  So that counter reset is done before resume

• General Purpose timer of STM32WL are not working in stop mode:
  See Reference Manual RM0453 Rev 4
  https://www.st.com/resource/en/reference_manual/rm0453-stm32wl5x-advanced-armbased-32bit-mcus-with-subghz-radio-solution-stmicroelectronics.pdf
  § 6.5 Low-power modes
  Table 45. Functionalities depending on system operating mode(1)
  
  Legend: Y = Yes (enable). O = Optional (disable by default and can be enabled by software). R = data retained. - = Not available. Gray cells indicate wake-up capability.

So at best, timer can run in sleep mode, as it is optional, (it is configurable).
But, in stm32duino core, the timer is not configured to run while in sleep mode.
Have a look at reference manual, RCC register RCC_APB1SMENR1, bitfield TIM2SMEN.
This bitfield is not managed in stm32duino. You can eventually manage it thanks to STM32Cube HAL API
(Note: HAL API are usable directly within Arduino sketch)

• From your description, it is not clear to me what means :

And with my code sometimes the interrupt for the rising edge isn't working

Are you talking about rising edge of the trigger (the one calling SINGAL_SON()) or of FREQUENCE_PIN ?
I suppose it is FREQUENCE_PIN .
Does it mean you lose 1 edge ? all edges? or at some point you miss one edge and then you miss all further edges ?

... the timer can't stop and the chip never goes in stop mode

I don't see in you code instruction to stop (pause) the timer (except a commented line).
Also I don't see the code to go in stop mode (except a commented line).

Can you clarify ?
Can you tell me how you know timer doesn't stop?
Can you tell me how you know chip never goes in stop mode ?

[HamadyDIA]

Thanks you for your message

(Question can we speak in french ?)

Can you tell me how you know timer doesn't stop?

I have the LED attached to the callback of the timer that continue to blink even without signal coming from outside.

Can you tell me how you know chip never goes in stop mode ?

I have a PPK2 that mesure the current consumption and it stays at 6mA

Also I don't see the code to go in stop mode (except a commented line).

With this fork made by move X the chip goes to sleep everytime it end a function. And is wakeup by the RTC.

`void CALLBACK_TIM2(){
detachInterrupt(digitalPinToInterrupt(FREQUENCE_PIN));
digitalWrite(LED_VERT,!digitalRead(LED_VERT));
App_son.frequence_finale=App_son.frequence_int;
tim2=true;
}

void INIT_TIMER_2(void) {
TIM_2->setOverflow(10, HERTZ_FORMAT); // 100ms
TIM_2->attachInterrupt(CALLBACK_TIM2);
TIM_2->setCount(0);
TIM_2->attachInterrupt(CALLBACK_TIM2);
TIM_2->resume();
}

void FREQUENCE_2(){
App_son.frequence_int++;
digitalWrite(LED_BLEU,!digitalRead(LED_BLEU));
}

void SINGAL_SON(void) {
INIT_TIMER_2();

attachInterrupt(digitalPinToInterrupt(FREQUENCE_PIN), FREQUENCE_2, RISING);
while(tim2==false){
}
tim2=false;
Serial2.begin(115200);
Serial2.println(App_son.frequence_finale);
App_son.frequence_finale=0;
App_son.frequence_int=0;
}`

With these modification the timer IRQ and all IRQ work but the chip stays in run mode. And if i add TIM2->pause() after the while(tim2==false) the timer IRQ don't work.

Thanks.

[ABOSTM]

With this fork made by move X the chip goes to sleep everytime it end a function

Ok, I am not aware of moveX fork, but AFAICS, due to while loop in SINGAL_SON()

while(tim2==false){
}

this prevent chip to go in lowpower mode (sleep ? or stop?) during the 100ms of timer2, because function doesn't end.
And system goes to LowPower when SINGAL_SON() ends (after timer 2 elapse and while waiting for new trigger on 1st GPIO)

Also you initial talk about stop mode, but now you are talking about sleep mode. This is 2 different modes in STM32 chips, with different capabilities. Can you clarify ?

And if i add TIM2->pause() after the while(tim2==false) the timer IRQ don't work.

Well, my guess would be that timer works for a while until pause() is reached.
Then maybe you miss to re enable your trigger and thus restart the timer (by calling SINGAL_SON()) ?