/** Reads the MSP430 supply voltage using the Analog to Digital Converter (ADC).
On ez430 boards, this is approx. 3600mV
@return Vcc supply voltage, in millivolts
*/
unsigned int getVcc3()
{
ADC10CTL0 = SREF_1 + REFON + REF2_5V + ADC10ON + ADC10SHT_3;  // use internal ref, turn on 2.5V ref, set samp time = 64 cycles
ADC10CTL1 = INCH_11;
delayMs(1);                                     // Allow internal reference to stabilize
ADC10CTL0 |= ENC + ADC10SC;                     // Enable conversions
while (!(ADC10CTL0 & ADC10IFG));                // Conversion done?
unsigned long temp = (ADC10MEM * 5000l);        // Convert raw ADC value to millivolts
return ((unsigned int) (temp / 1024l));
}