Vref - MSP-TS430PN80 development board needs a cap?

In teh schematic, C6 is marked as "not ass'd". That means it is in the schematic, so the pad is on the board, but the capacitor is intentionally not placed there. I don't have the 47x datasheet at hand, but on some devices, the reference output pin is multiplexed with outher port functionality which might be affected by the capacitor if it were assembled.

On the photo of the board, as posted on teh I website, C6 is not assembled. If it is on your board, either someone has added it, or TI has changed the placement without changing the docs. (maybe because on this particular target board and its target processors, this pin always needs C6 and is not shared)

Do i need to solder wires myself from the c6 capacitor on the board to the corresponding pins as shown on the board schematic - my vref is 0V which i believe is holding me back in progression with my pulse oximeter project - is adding this c6 cap the answear ?

thank you

- satu

The wires should be already there,a s are teh pads for soldering the capacitor. And in your case, teh capacitor seems to be there too.

However, even without capacitor, the Vref voltage on the pin shouldn't be 0V. What does your code say? Do you ever switch the reference on at all? ( it is done in ADC12 module or - if the MSP has one- the REF module. The DAC only uses it if it is on.)

The code is below for the ADC 12 i am having trouble understanding it
   
    /* Configure ADC12 */
    ADC12CTL0 &= ~ENC;                      // Enable conversions
                                            // Turn on the ADC12, and
                                            // set the sampling time
    ADC12CTL0 = ADC12ON + MSC + SHT0_4 + REFON + REF2_5V;
    ADC12CTL1 = SHP + SHS_1 + CONSEQ_1;     // Use sampling timer, single sequence,
                                            // TA1 trigger(SHS_1), start with ADC12MEM0
    ADC12MCTL0 = INCH_1 + SREF_1;           // ref+=Vref, channel = A1 = OA0
    ADC12MCTL1 = INCH_3 + SREF_1 + EOS;     // ref+=Vref, channel = A3 = OA1
    ADC12IE = BIT1;                         // ADC12MEM1 interrupt enable
    ADC12CTL0 |= ENC;                       // Enable the ADC
    ADC12CTL0 |= ADC12SC;                   // Start conversion   
   
    /* Configure Timer */
    TACTL = TASSEL0 + TACLR;                // ACLK, clear TAR,
    TACCTL1 = OUTMOD_2;
    TACCTL0 = CCIE;
                                            // This gives a sampling rate of
                                            // 512sps
    TACCR0 = 31;                            // Do two channels, at
                                            // 512sps each.
    TACCR1 = 10;                            // Allow plenty of time for the
                                            // signal to become stable before
                                            // sampling  
    TACTL |= MC_1;                          // Timer A on, up mode    

Overall i think my dac12  outputs are not working properly - i always measure 0v at the dac 12 pins 5 and 10

hi,

   have u completed pulse oximeter design...even my LED'S are not driven by h bridge...cn u help me in finding out my error...