5 years later - NXP ADCs aren't working

Question

Some time ago I was trying to programm the ADC on the NXP's LPC3143 withouth sucess. Now 5 years later I buy myself an LPC4088 Quick start board and try it with LPC4088. And again the same problem persists with ADC! I just can't seem to make it work while I/O config, GPIO, timers and PWM work like a charm...

I am always programming MCU's by reading the user manual. So after reading the manual this is what I came up with:

LPC4088-ioconfig.h

//register definitions for IOCONFIG peripheral
//this one is "type A"

#define IOCON_P1_31    (*((volatile unsigned int *) 0x4002C0FC)) 

LPC4088-system.h

//register definitions for system & clock peripheral
//used to turn on peripherals

#define PCONP          (*((volatile unsigned int *) 0x400FC0C4))

LPC4088-gpio.h

//register definitions for GPIO peripheral 
//only port 1

#define DIR1           (*((volatile unsigned int *) 0x20098020))    
#define MASK1          (*((volatile unsigned int *) 0x20098030))
#define PIN1           (*((volatile unsigned int *) 0x20098034))
#define SET1           (*((volatile unsigned int *) 0x20098038))
#define CLR1           (*((volatile unsigned int *) 0x2009803C))

LPC4088-adc.h

//register definitions for ADC peripheral

#define CR             (*((volatile unsigned int *) 0x40034000))
#define GDR            (*((volatile unsigned int *) 0x40034004))
#define INTEN          (*((volatile unsigned int *) 0x4003400C))

#define DR0            (*((volatile unsigned int *) 0x40034010))
#define DR1            (*((volatile unsigned int *) 0x40034014))
#define DR2            (*((volatile unsigned int *) 0x40034018))
#define DR3            (*((volatile unsigned int *) 0x4003401C))
#define DR4            (*((volatile unsigned int *) 0x40034020))
#define DR5            (*((volatile unsigned int *) 0x40034024))
#define DR6            (*((volatile unsigned int *) 0x40034028))
#define DR7            (*((volatile unsigned int *) 0x4003402C))

#define STAT           (*((volatile unsigned int *) 0x40034030))
#define TRM            (*((volatile unsigned int *) 0x40034034))

main.c

#include "LPC4088-ioconfig.h"
#include "LPC4088-system.h"
#include "LPC4088-gpio.h"
#include "LPC4088-adc.h"

int main(){

    //***********************************************************

    //we set P1.13 (port 1, pin 13) as GPIO, no pull-up, no hysteresis, not inverted, standard, push-pull
    IOCON_P1_13 &= !(0x67F);

    //we turn on GPIO peripheral
    PCONP |= (1<<15);    

    //set P1.13 as an output GPIO
    DIR1 |= (1<<13);

    //setting a mask for pin P1.13
    MASK1 &= !(1<<13);

    //***********************************************************

    //configure pin P1.31 as an input ADC0_IN5 (channel 5)
    IOCON_P1_31 |= 0b011;

    //we disable pullup or pulldown resistors on pin P1.31
    IOCON_P1_31 &= !(0x3<<4);

    //we configure pin P1.31 for ADMODE
    IOCON_P1_31 &= !(1<<7);

    //we turn on the ADC peripheral
    PCONP |= (1<<12);

    //we divide PCLK delimo with 99+1=100 (only for precaution)
    CR |= (99<<8);

    //we start the ADC
    CR |= (1<<21);

    //we disable ADC interrupts
    INTEN &= !(0x1FF);

    //we choose chanel 5 which is the only one that we choose 
    CR &= !(0xFF);
    CR |= (1<<5);

    //before choosing "burst mode" we need to turn off the conversion
    CR &= !(0x7<<24);

    //we choose "burst mode" - conversion starts and is continuous
    CR |= (1<<16);

    //***********************************************************


    while(1){

        //we wait for the conversion to finish and we save the result
        //we right-shift because value is stored in DR5 bits 15:4!

        while( (DR5 & (1<<31) ) != (1<<31) );
        int result = ( (DR5 & 0xFF0) >> 4);

        //12-bit has a max value of 0xFFF - we compare result to the half of this value - 0x7FF.

        if (result >= 0x7FF){
            //turn on an LED on pin P1.13
            SET1 |= (1<<13);
        }
        else{
            //turn off an LED on pin P1.13
            CLR1 |= (1<<13);
        }
    }       
}

Here is also a more detailed interface description for LPC4088 Quick start board - my external potentiometer output is connected to the P1.31, while the LED is already embedded onto the board:

Answer 1

Ok so I worked my ass off for this one for 10 hours straigth and went to bed at 4:30 in the morning... And here it is - the working example for LPC4088 ADC (header files are the same as in the question):

#include "LPC4088-ioconfig.h"
#include "LPC4088-system.h"
#include "LPC4088-gpio.h"
#include "LPC4088-adc.h"

int main(){

    IOCON_P1_13 &= !(0x67F);
    IOCON_P1_31 |= 0b011;
    IOCON_P1_31 &= !(0b11<<4);
    IOCON_P1_31 &= !(1<<7);
    IOCON_P0_23 |= 0b011;
    IOCON_P0_23 &= !(0b11<<4);
    IOCON_P0_23 &= !(1<<7); 


    PCONP |= (1<<15);    
    DIR1 |= (1<<13);
    MASK1 &= !(1<<13);


    PCONP |= (1<<12);
    INTEN &= !(0x1FF);
    CR &= !(0x7<<24);
    CR &= !(1<<16);


    while(1){
        CR |= (1<<21);
        CR |= (0x1<<24);
        while( (STAT & (1<<0) ) == 0x0 );
        CR &= !(0x1<<24);

        unsigned int result = 0;
        result = ( (DR0 & 0xFFF0) >> 4);

        CR &= (1<<21);      

        if (result > 0x7FF){
            SET1 |= (1<<13);
        }
        else{
            CLR1 |= (1<<13);
        }
    }       
}

Much simpler that examples from LPC-Open. And I bet this will be helpful to some of you guys... I intend to open my GIT with examples like these for all of the peripherals. But now I only know how to manipulate ioconfig, gpio, timer, pwm and adc.