Help with the sine wave extreme point sampling program based on MSP430

心在流浪

Help with the sine wave extreme point sampling program based on MSP430 [Copy link]

I need to make a sine wave extreme point sampling program. The following is my peak sampling program. How can I modify it? My idea is to multiply the array number of the sampled number by the sampling interval time to get the horizontal coordinate of the corresponding point. I don't know if it will work. I am a novice and don't know how to determine the sampling interval. . . #include
#define n 255
int ADC_buf[n];
unsigned char j;
unsigned char i=0;
int  g_zhong,ADC_MAX;
float  MAX_true;
float ADC_true;
int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  ADC12CTL0 = ADC12SHT0_2 + ADC12ON;         // Sampling time, ADC12 on
  ADC12CTL1 = ADC12SHP;                     // Use sampling timer
  ADC12IE = 0x01;                           // Enable interrupt
  ADC12CTL0 |=ADC12ENC;
  P6SEL |= 0x01;                            // P6.0 ADC option select
  //P1DIR |= 0x1C;                            // P1.0 output
  P1DIR |= 0x01;

  while (1)
  {
    ADC12CTL0 |= ADC12SC;                   // Start sampling/conversion
    __bis_SR_register(LPM0_bits + GIE);     // LPM0, ADC12_ISR will force exit
    //__no_operation();                       // For debugger
    while(i==0)
     {

         for(j=1;jADC_buf[j])
           {
             g_zhong=ADC_buf[j-1];
             ADC_buf[j-1]=ADC_buf[j];
             ADC_buf[j]=g_zhong;
           }
           ADC_MAX=ADC_buf[n-1];
         }
       MAX_true=ADC_MAX*3.30/4095;
       P1OUT |= BIT0;
     }
     }

}

#pragma vector = ADC12_VECTOR
__interrupt void ADC12_ISR(void)
{
        if(ADC12MEM0>=0)
                {//P1OUT|=0x1C;
            P1OUT |= BIT0;
            ADC_buf[i]=ADC12MEM0;
            i++;
                i%=n;}

         __bic_SR_register_on_exit(LPM0_bits);   // Exit active CPU
}

huo_hu

This depends on how you trigger AD. In the case of continuous conversion, the AD conversion time is the soft trigger interval, which is the trigger interval. This is a routine program.

心在流浪

The following is my modified program. The continuous sampling of the extreme points of the sine wave can collect data, but the extreme point MAX_true cannot be obtained. #include
#define n 100
int ADC_buf[n];
unsigned char j;
unsigned char i=0;
int  ADC_MAX;
float  MAX_true;
int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P6SEL |= 0x01;                            // P6.0 ADC option select
  ADC12CTL0 = ADC12SHT0_8 + ADC12ON+ADC12MSC;         // Sampling time, ADC12 on
  ADC12CTL1 = ADC12SHP+ADC12CONSEQ_2;                     // Use sampling timer
  ADC12IE = 0x01;                          // Enable interrupt
  ADC12CTL0 |=ADC12ENC;
  P1DIR |= 0x01;

  while (1)
  {
    ADC12CTL0 |= ADC12SC;                   // Start sampling/conversion
    __bis_SR_register(LPM0_bits + GIE);     // LPM0, ADC12_ISR will force exit
    while(i==0)
     {

         for(j=1;j=ADC_buf[j])
           {
                   ADC_MAX=ADC_buf[j-1];
                   MAX_true=ADC_MAX*3.30/4095;
                   P1OUT |= BIT0;
                   j=1;
           }
           P1OUT &=~ BIT0;
         }

     }
     }

}

#pragma vector = ADC12_VECTOR
__interrupt void ADC12_ISR(void)
{
        if(ADC12MEM0>=0)
                {

            ADC_buf[i]=ADC12MEM0;
            i++;
                i%=n;}

         __bic_SR_register_on_exit(LPM0_bits);   // Exit active CPU
}