Sleep and interrupt in Sduino

[chirag-uAtech]

Hi community,

I am new to Sduino and Stm8s. Have some prior experience working with Arduino, AVRs & STM32. I chose STM8s due to its lower price for a project. After developing the project, I need to reduce the current usage as much as possible to make the system Standby Mode. I have tried and failed while using Interrupt with a button.

For the sake of clear understanding, I want to develop a project that can control LED using a Push Button. I want the system to be in sleep mode for the rest of the time.

The sduino repo contains an example code for interrupt, that is:

#define BUTTON  PA2

volatile uint8_t flag = 0;

void on_button_pressed(void)
{
    flag = 1;
}
void setup()
{
    pinMode(LED_BUILTIN, OUTPUT);
    digitalWrite(LED_BUILTIN, 1);   // turn off the LED

    pinMode(BUTTON, INPUT_PULLUP);

    attachInterrupt(digitalPinToInterrupt(BUTTON), on_button_pressed, FALLING);
}
void loop()
{
    if (flag) {
        digitalWrite(LED_BUILTIN, 0);
        delay(300);
        digitalWrite(LED_BUILTIN, 1);
        flag = 0;
    }
}

The code does not get compiled in Arduino. On searching the internet for a bit, I found changing digitalPinToInterrupt(pin); to digitalPinToPort(pin); may work. The code gets compiled now but the result remains unexpected.

After digging some more into the problem, I found one more possible solution:

GPIO_Init(GPIOA, GPIO_PIN_3, GPIO_MODE_IN_FL_IT);
  disableInterrupts();
  EXTI_SetExtIntSensitivity( EXTI_PORT_GPIOA, EXTI_SENSITIVITY_RISE_ONLY);  
  enableInterrupts();
  attachInterrupt(INT_PORTA & 0xFF,ISR,0);

Source: https://github.com/tenbaht/sduino/issues/92

I tried this as well in my code. But still unable to make it work.

My requirement is to attachInterrupt on pin PA2 & use it to wake from sleep. Similar issues have been raised multiple times but not resolved completely.

Kindly provide some input on this problem.

[MR-IC]

You can implement it simply by writing a command "wfi" it halts the microcontroller and waits for the interrupt to occur.

Before entering this command make sure that you have proper interrupt attached.

[chirag-uAtech]

@MR-IC How do I do that? I am new to development on STM8 and can't find any function in the whole sduino library relating to this. It would help greatly if you can attach a simple code to go to sleep and then wake from button using EXTI.