dual channel ADC conversion

[muzay 0]

hi everyone, 

 

i'm sampling from single channel ADC and send the data over UART. 

now i need to two channel simultaneously and send the data.

 

for one channel my code is below:

-----------------------------------------------

 ADC10CTL1 = INCH_5 + ADC10DIV_3 ;         // Channel 5, ADC10CLK/4

 ADC10CTL0 = SREF_0 + ADC10SHT_3 + ADC10ON + ADC10IE;  //Vcc & Vss as reference

 ADC10AE0 |= BIT5;

 ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start, single measure! 

 

while(1)           {

      if(!((P1IN & BUTTON)==BUTTON)) 

      {

         ADC10CTL0 |= ENC + ADC10SC;

         value1 = ADC10MEM>>2; // used only 8 bits of 10bits adc conversion...

 while ((UCA0STAT & UCBUSY)); // Wait if line TX/RX module is busy with data

         UCA0TXBUF = value1;

              }

  }

}

-------------------------------------------------

can you please help me to make following changes...

 

i need to use p1.4 and p1.5 for ADC conversion (two channel), and the ADC referance voltage should be 2.5V or lower.

 

thank you all...

[muzay 0]

i tried to activate ADC for p1.4 and p1.5 succesively, but it gave me only zeros.. , 

i really need suggestions...

thanks..

[RobG 1,892]

Look at this example, you will only need to make few small changes.

ADC10CTL1 = INCH_5 + CONSEQ_1;
ADC10CTL0 = ADC10SHT_2 + MSC + ADC10ON + ADC10IE;
ADC10DTC1 = 0x02;
ADC10AE0 |= 0x30;

[muzay 0]

 

Look at this example, you will only need to make few small changes.

ADC10CTL1 = INCH_5 + CONSEQ_1;
ADC10CTL0 = ADC10SHT_2 + MSC + ADC10ON + ADC10IE;
ADC10DTC1 = 0x02;
ADC10AE0 |= 0x30;

 

Thank you a lot RobG! it worked pretty well...

Here is my code who needs to see....

 

 

 

#include  <msp430g2553.h> // System define for the micro that I am using

 

#define RXD        BIT1 // Check your launchpad rev to make sure this is the case. Set jumpers to hardware uart.

#define TXD        BIT2 // TXD with respect to what your sending to the computer. Sent data will appear on this line

#define BUTTON     BIT3

 

unsigned int adcValues[2] = {0,0}; // ADC buffer

 

void main(void)

{

WDTCTL = WDTPW + WDTHOLD;         // Stop Watch dog timer

 

BCSCTL1 = CALBC1_16MHZ;

DCOCTL = CALDCO_16MHZ;

 

P1DIR &=~BUTTON;                  // Ensure button is input (sets a 0 in P1DIR register at location BIT3)

 

P1OUT |=  BUTTON;                 // Enables pullup resistor on button

P1REN |=  BUTTON;

 

P1SEL = RXD + TXD ;               // Select TX and RX functionality for P1.1 & P1.2

P1SEL2 = RXD + TXD ;              //

UCA0CTL1 |= UCSSEL_2;             // Have USCI use System Master Clock: AKA core clk 16MHz

 

UCA0BR0 = 130;                    // 16 MHz 9600, see user manual

UCA0BR1 = 6;                      //

 

UCA0MCTL = UCBRS0;                // Modulation UCBRSx = 1

UCA0CTL1 &= ~UCSWRST;             // Start USCI state machine

 

// Set ADC

ADC10CTL1 = INCH_5 + CONSEQ_1;

ADC10CTL0 = SREF_1 + REFON + ADC10SHT_2 + MSC + ADC10ON + ADC10IE;

ADC10DTC1 = 0x02;

ADC10AE0 |= 0x30;

 

while (1)

{

if ( ! ((P1IN & BUTTON) == BUTTON)) // Was button pressed?

{

ADC10CTL0 &= ~ENC;

while (ADC10CTL1 & BUSY);

 

ADC10SA = (unsigned int)adcValues;

ADC10CTL0 |= ENC + ADC10SC;

 

while ((UCA0STAT & UCBUSY)); // Wait if line TX/RX module is busy with data

UCA0TXBUF = adcValues[0];

while ((UCA0STAT & UCBUSY)); // Wait if line TX/RX module is busy with data

UCA0TXBUF = adcValues[1];

}

}

}

 

// 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)

}

[Bujhm666 0]

Show also this example:

#include <msp430g2553.h>

unsigned int adcValues[6] = { 0, 0, 0, 0, 0, 0 };

void main(void) {
  WDTCTL = WDTPW + WDTHOLD; // Stop WDT

  BCSCTL1 = CALBC1_1MHZ;
  DCOCTL = CALDCO_1MHZ;

  P2DIR |= BIT2;
  P2OUT &= ~BIT2;

  ADC10CTL1 = INCH_5 + CONSEQ_1;
  ADC10CTL0 = ADC10SHT_2 + MSC + ADC10ON + ADC10IE;
  ADC10DTC1 = 0x06;
  ADC10AE0 |= 0x3F;

  CCTL0 = CCIE; // CCR0 interrupt enabled
  CCR0 = 180; // sample every ~1.5ms
  TACTL = TASSEL_2 + MC_1 + ID_3; // SMCLK/8, upmode

  _bis_SR_register(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}

// Timer A0 interrupt service routine
#pragma vector = TIMER0_A0_VECTOR
__interrupt void Timer_A(void) {

  ADC10CTL0 &= ~ENC; // disable conversion
  while (ADC10CTL1 & BUSY)
    // make sure ADC is done
    ;
  ADC10SA = (unsigned int) &adcValues[0]; // set data buffer start address
  ADC10CTL0 |= ENC + ADC10SC; // start sampling and conversion
}

// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR(void) {

  //ADC is done, do something with adcValues

  if (adcValues[0] > 500) { // A5 is in adcValues[0], A0 in adcValues[5]
    P2OUT |= BIT2;
  } else {
    P2OUT &= ~BIT2;
  }
}