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430

Other Parts Discussed in Thread: OPA690, DAC904

请问    MSP430 LaunchPad     上的AD转换怎么在程序中调用啊?

怎么用C语言编写一个程序    “控制DDS输出的是一个固定频率的信号”。

  • 这是launch pad的ADC程序:

    #include <msp430.h>

    int main(void)
    {
    WDTCTL = WDTPW + WDTHOLD; // Stop WDT
    ADC10CTL0 = SREF_1 + ADC10SHT_2 + REFON + ADC10ON + ADC10IE;
    __enable_interrupt(); // Enable interrupts.
    TACCR0 = 30; // Delay to allow Ref to settle
    TACCTL0 |= CCIE; // Compare-mode interrupt.
    TACTL = TASSEL_2 | MC_1; // TACLK = SMCLK, Up mode.
    LPM0; // Wait for delay.
    TACCTL0 &= ~CCIE; // Disable timer Interrupt
    __disable_interrupt();
    ADC10CTL1 = INCH_1; // input A1
    ADC10AE0 |= 0x02; // PA.1 ADC option select
    P1DIR |= 0x01; // Set P1.0 to output direction

    for (;;)
    {
    ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start
    __bis_SR_register(CPUOFF + GIE); // LPM0, ADC10_ISR will force exi
    if (ADC10MEM < 0x88) // ADC10MEM = A1 > 0.2V?
    P1OUT &= ~0x01; // Clear P1.0 LED off
    else
    P1OUT |= 0x01; // Set P1.0 LED on
    }
    }

    // ADC10 interrupt service routine
    #pragma vector=ADC10_VECTOR
    __interrupt void ADC10_ISR (void)
    {
    __bic_SR_register_on_exit(CPUOFF); // Clear CPUOFF bit from 0(SR)
    }

    #pragma vector=TIMER0_A0_VECTOR
    __interrupt void ta0_isr(void)
    {
    TACTL = 0;
    LPM0_EXIT; // Exit LPM0 on return
    }

  • 1、DDS用哪颗?AD9954?AD9851?AD9833?AD9834?

    2、DDS也可以用DAC+FPGA做,DAC904+FPGA+OPA690

  • DDS用的是一个芯片AD9850,使用单片机430  LaunchPad编程  控制

  • 可以使用集成SPI与AD9850通讯即可,AD9850工作在3.3V的时候容易出现数据错误导致输出频率错误。计量减少数据线长度。