Hi iam new to MSP430 SD24, Please help
after reading the datasheet I am confused about the Conversion result ,and reconversion of the result back to voltage.
I could not find register to set SD24 adc in unipolar mode.also, my input to ADC is in 0-200mv range .
For 30 mV input I am getting Result = 0x00833955 . When i back calculated iam not getting the 30 mV
And with out giving any input ADC is reading some values .
I am USING MSP430F6451a controller.
ADC Settings
Vref - internal 1.2v
Bipolar ,Binary ,Right aligned result.
Below is my code :
//////////////////////////////////////////////////////////////
volatile unsigned long results[6];
int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
SD24BCTL0 = SD24SSEL__SMCLK /* Clock is SMCLK */
| SD24PDIV_3 /* Divide by 16 */
| SD24DIV3
| SD24REFS /* Use internal reference */
| SD24OV32;
SD24BCTL1 = 0;
SD24BTRGOSR = OSR__256;
SD24BCCTL0 = SD24SCS_4; // Right-aligned, group 0 ,
SD24BINCTL0 |= SD24GAIN_1;////Select gain 1
SD24BPRE0 = 0; //Digital filter preload value
SD24BIE = SD24IE2; // Enable interrupt
__delay_cycles(0x3600); // Delay
SD24BCTL1 |= SD24GRP0SC; // Set bit to start conversion
__bis_SR_register(GIE);
while(1);
}
///////////////////////////////////////////////////////////////////////////////////
#pragma vector=SD24B_VECTOR
__interrupt void SD24BISR(void)
{
switch (SD24BIV)
{
case SD24BIV_SD24OVIFG: // SD24MEM Overflow
break;
case SD24BIV_SD24TRGIFG: // SD24 Trigger IFG
break;
case SD24BIV_SD24IFG0: // SD24MEM0 IFG
break;
case SD24BIV_SD24IFG1: // SD24MEM1 IFG
break;
case SD24BIV_SD24IFG2: // SD24MEM2 IFG
results[0] = SD24BMEMH0; // Save CH0 results (clears IFG)
results[0] = (results[0] << 16) | SD24BMEML0; // Concatenate lower and upper words
break;
}
__bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
}
