[讨论] msp430f24x ADC采样问题

XiaoChuan 2016-3-29 15:01 楼主

ADC采样数据总是不对，不知道是不是设置不对，构思是这样的，定时器定时156.25us采样一个点，需要采样四组

外接晶振8M

void initTA(void) //156.25us
{

CCTL0 = CCIE; // CCR0 interrupt enabled
CCR0 = 1247;
TACTL = TASSEL_2 + MC_2; // SMCLK, contmode

}

/*===========================================================================
扫描采样AN0-AN5共6个通道模拟信号
=============================================================================*/
void initAdc1(void)
{

ADC12CTL0 &= ~ENC;
P6SEL = BIT4 | BIT5 | BIT6 ;                         // Enable A/D channel inputs
ADC12CTL0 |= ADC12ON+MSC+SHT0_2;       // Turn on ADC12, extend sampling time采样时间?  MSC次采样和转换
ADC12CTL1 |= SHP+CONSEQ_1+ADC12SSEL_3;
ADC12MCTL0 |= SREF_0;                   // 模拟参考电压
ADC12MCTL4 |= INCH_4;                   // ref+=AVcc, channel = A4
ADC12MCTL5 |= INCH_5;                   // ref+=AVcc, channel = A5
ADC12MCTL6 |= INCH_6+EOS;                   // ref+=AVcc, channel = A6，end seq
ADC12IE=0X40;
ADC12CTL0 |= ENC;                         // Enable conversions

}
/*------------------------------------------------------------------------------
ADC采样6次后中断,读取转换结果并关闭自动采样
-------------------------------------------------------------------------------*/

#pragma vector=ADC12_VECTOR
__interrupt void ADC12ISR (void) //关闭自动采样
{
// Enable conversions

sambuffh[IC][phase]=ADC12MEM4;
sambuffh[IB][phase]=ADC12MEM5;
sambuffh[IA][phase]=ADC12MEM6;
// ADC12IFG=0;

}

void main(void)
{
int i;
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer

BCSCTL1 &=~XT2OFF;//启动XT2时钟

do
{
IFG1 &= ~OFIFG;                         // Clear OSCFault flag
for (i = 0xFF; i > 0; i--);             // Time for flag to set
}
while ((IFG1 & OFIFG));                // OSCFault flag still set?
  BCSCTL2 |= SELM_2+SELS ;                      //  MCLK  SMCLK = XT2模式    SELM_2 + SELS

initTA();
initAdc1();
_EINT();
while(1)
{

;
}

}
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)  //156.25us
{
   phase++;
   ADC12CTL0 |= ENC+ADC12SC;
CCR0 = 1247;
}