void ADC_init( void ) {


    // Enabled the Power controler in PCONP register. According the Table 46. the 12th bit is PCADC
    LPC_SC->PCONP |= (1 << 12);

    // Poti is connected to port P0.25. We have to put the port P0.25 into the AD0.2 moe for anlaoge to digital conterting.
    LPC_PINCON->PINSEL1 &= ~(0x3 << 18); // Remove all bits, Port P0.25 gets GPIO
    LPC_PINCON->PINSEL1 |=  (0x1 << 18); // Switch P0.25 to AD0.2

    // No pull-up no pull-down (function 10) on the AD0.2 pin.
    LPC_PINCON->PINMODE1 &= ~(0x3 << 18);
    LPC_PINCON->PINMODE1 |=  (0x1 << 18);

    // A/D Control Register (Section 29.5.1)
    LPC_ADC->ADCR = ( 1 <<  2)  |    // SEL=1        select channel 0~7 on AD0.2
                    ( 4 <<  8)  |    // ADC clock is 25 MHz/5
                    ( 0 << 16 ) |    // BURST = 0    no BURST, software controlled
                    ( 0 << 24 ) |    // START = 0    A/D conversion stops */
                    ( 0 << 27 ) |    // EDGE = 0     CAP/MAT singal falling,trigger A/D conversion
                    ( 1 << 21);      // PDN = 1      normal operation, Enable ADC

    // Enabling A/D Interrupt Enable Register for all channels (Section 29.5.3)
    LPC_ADC->ADINTEN = ( 1 <<  8);

    // Registering the interrupt service for ADC
    NVIC_EnableIRQ( ADC_IRQn );
}