How can I increase the amplitude of the sine wave generated from the pwm of the stm8s003f3 microcontroller ?? Is there any particular formula to calculate that??

[SANAN.1]

I have a haptic button where the vibration has been set as soon as the pwm is genereated, I want to increase the vibration by changing the amplitude of the sine wave generated from the pwm, Can I know how can I do that??

[Peter BENSCH]

Since you have not posted any code, we can only guess: I assume that the sine is output via PWM in your program with full amplitude, i.e. with a peak value of 100%.

If you want to increase the resulting vibration, you have to increase the amplitude outside of the controller using an amplifier, e.g. with an opamp. However, the specific implementation depends on your setup, because you also did not mention how the vibration itself is generated and which signals can be processed there.

Regards

/Peter

[SANAN.1]

Hello Peter here is the sine structure of the code and the pmw value, here i want to know the relation between the duty cycle and sine signal and change the amplitude to gain more vibration

static void LoadValueIntoSinStruct(void)

{

 uint8_t offset=0,diff=0;

  

 while(offset <= (nbr_of_samples_half/2))

 {

  /*First half of upper half samples of sine wave is loaded into "value" of sin structure.*/

   sin.Value[offset] = sample[offset]; 

   offset++;            

 }

  

 diff = (uint8_t)(offset - 1);

 while(offset < nbr_of_samples_half)

 {                   

   diff--;  

   /* Second half of upper half samples of sine wave is loaded into "value" of sin structure.*/

   sin.Value[offset] = sample[diff];   

   offset++;             

 }  

 /*Index is initialized to 0.Sin wave upper half is generated at start*/

 sin.Index = 0;            

 sin.Up = TRUE;

}

INTERRUPT_HANDLER(TIM2_UPD_OVF_BRK_IRQHandler, 13)

{

 uint8_t PWM_Value = 0; 

 if (counter >= COUNTER)        

 { 

  /* Reset the counter value*/

  counter = 0;

  /* Upper half cycle of sine wave */

  if (sin.Up == TRUE)

  {

   /* Load the duty cycle register for upper half cycle of sine wave.*/ 

   /* This is achieved by adding sample values into AVERAGE_AMP.*/

   PWM_Value = (uint8_t)(AVERAGE_AMP + sin.Value[sin.Index]);

  }

  else 

  { 

   /* Lower half cycle of sine wave */ 

   /* Load the duty cycle register for lower half cycle of sine wave. */ 

   /* This is achieved by  subtracting sample values into AVERAGE_AMP. */   

   PWM_Value = (uint8_t)(AVERAGE_AMP - sin.Value[sin.Index]);

  }

  /* Set the Capture Compare1 Register value */

//  TIM2_SetCompare1(PWM_Value);

  TIM2->CCR1H = (uint8_t)(PWM_Value >> 8);

  TIM2->CCR1L = (uint8_t)(PWM_Value);

  /*Increment the index for pointing to wardsnext sample value to be loaded */

  sin.Index++;     

  if (sin.Index == nbr_of_samples_half) 

  {

   /* Reset the index value */

   sin.Index = 0;

   /* Lower half sin wave is activated if previously it was upper half and vice-versa */

   sin.Up = (bool_t)(~sin.Up);

  } 

 }

 /* Increment the counter value at each overflow interrupt */

 counter++;

 //TIM2_ClearITPendingBit(TI21_IT_UPDATE);

 TIM2->SR1 = (uint8_t)(~(uint8_t)TIM2_IT_UPDATE);

}

[SANAN.1]

basically I want to know why sinusodial signal is genereated from the pwm, its realtion with pwm??