CCS: Problem with a ADC conversion on MSP432

Tool/software: Code Composer Studio

Hello Fellows,

I have a small problem with my MSP432, I configured the pin P5.4, to convert a signal, where my reference voltage is 3.3v. To program this I have used CCS, in classic mode registers, before I connect the P5.4 to sensor output, I measure the voltage, and I obtain a oscillation between 1.10 and 1.15V. Is this normal?

Follow code:

#include "adc.h"
#include "lcd.h"
#include "stdio.h"		// Libreria de entrada y salida de texto
extern char Mensaje[];

void adc(void){
    volatile unsigned int i;

/*ADC CONFIGURATION*/
P5->SEL1 |= BIT4;
P5->SEL0 |= BIT4;

/*ENABLE GLOBAL INTERRUPTS*/
__enable_irq();

/*ENABLE ADC INTERRUPT IN NVIC MODULE*/
NVIC->ISER[0] = 1 << ((ADC14_IRQn) & 31);


 /*Sampling time, S&H=16, ADC14 on*/
 ADC14->CTL0 = ADC14_CTL0_SHT0_2 | ADC14_CTL0_SHP | ADC14_CTL0_ON;
 ADC14->CTL1 = ADC14_CTL1_RES_2;


 ADC14->MCTL[0] |= ADC14_MCTLN_INCH_1;
 ADC14->IER0 |= ADC14_IER0_IE0;

 SCB->SCR &= ~SCB_SCR_SLEEPONEXIT_Msk;

   while (1)
    {
        for (i = 20000; i > 0; i--);

        // Start sampling/conversion
        ADC14->CTL0 |= ADC14_CTL0_ENC | ADC14_CTL0_SC;
        __sleep();

        __no_operation();
    }

}

void ADC14_IRQHandler(void) {

	int value_adc=ADC14->MEM[0];
	float value_vol= value_adc * (3.3/4096);
	//sprintf(Mensaje,"%d",value_adc);
	sprintf(Mensaje,"%1.2f",value_vol);
	LCD_SetText(Mensaje,5 ,0);

}