CCS/MSP430FG4618: ADC Reading from 3-axis accelerometer adxl335.

Tool/software: Code Composer Studio

Dear,

I am having an issue reading the data from 3-axis accelerometer adxl335 using adc. I can only read correctly x-y or x-y at the same time. I cannot read correctly x-y-z at the same time. Will someone please check if my adc configuration is correct? Thank you!

void ADC_setup(void) {
    int i =0;

    P6DIR &= ~(BIT3 | BIT4 | BIT7);             // Configure P6.3, P6.4 and P6.7 as input pins
    P6SEL |= BIT3 | BIT4 | BIT7;                // Configure P6.3, P6.4 and P6.7 as analog pins
    /* ***** ADCCore configuration ***** */
    /* Reset REFMSTR to enable control of reference voltages by ADC12 */
    ADC12CTL0 &= ~ENC;

    /*
     * Initialize control register ADC12CTL0
     * ADC12ON = 1 => Turn on ADC12
     * STH0x   = 9 => Sample-and-Hold time takes 384 clock cycles
     * MSC     = 1 => ADC12 Multiple Sample Conversion
     */
    ADC12CTL0 = ADC12ON | SHT0_9 | MSC;         // Configure ADC converter

    /*
     * Initialize control register ADC12CTL1
     * SHP       = 1     => Sample/Hold Pulse Mode
     * CONSEQx   = 1     => Conversion sequence mode: Sequence of Channel
     */
    ADC12CTL1 = SHP | CONSEQ_1;                 // Use sample timer, single sequence

    /* ***** Channels configuration ***** */
    ADC12MCTL0 = INCH_3;                        // ADC A3 pin - Stick X-axis
    ADC12MCTL1 = INCH_4;                        // ADC A4 pin - Stick Y-axis
    ADC12MCTL2 = INCH_7 | EOS;                  // ADC A7 pin - Stick Z-axis
                                                // EOS - End of Sequence at ADC12MCTL2

    ADC12IE |= 0x04;                            // Enable ADC12IFG.1 at BIT2 (the EOS ADC Channel)
    for (i = 0; i < 0x3600; i++);               // Delay for reference start-up
    ADC12CTL0 |= ENC;                           // Enable conversions
}

void main(void) {
    WDTCTL = WDTPW +WDTHOLD;                    // Stop WDT
    TimerA_setup();                             // Setup timer to send ADC data
    ADC_setup();                                // Setup ADC
    UART_intilize();                            // Setup UART for RS-232
    _EINT();

    while (1){
        __bis_SR_register(LPM0_bits + GIE); // Enter LPM0

    }
}

#pragma vector = ADC12_VECTOR
__interrupt void ADC12ISR(void) {
    ADCXval = ADC12MEM0;                  // Move results, IFG is cleared
    ADCYval = ADC12MEM1;
    ADCZval = ADC12MEM2;
    __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
}

#pragma vector = TIMERA0_VECTOR
__interrupt void timerA_isr() {
    ADC12CTL0 |= ADC12SC;               // Start conversions every 0.25s
    __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
}

Best,

Tony