LPC1768 problem with timer0

OK, I've just corrected my code and now works better. I know how to read ADC register, I make it in main loop but the logic of LEDs is still bad. It works only one way - you talked about it. The LEDs don't turn off but turning on works very well. Any snippet ? And small prompt ? Thank you for all answers and advices... :)

My code:

/*
===============================================================================
 Name        : main.c
 Author      :
 Version     :
 Copyright   : Copyright (C)
 Description : main definition
===============================================================================
*/

#ifdef __USE_CMSIS
#include "LPC17xx.h"
#endif

#include <cr_section_macros.h>
#include <NXP/crp.h>

// Variable to store CRP value in. Will be placed automatically
// by the linker when "Enable Code Read Protect" selected.
// See crp.h header for more information
__CRP const unsigned int CRP_WORD = CRP_NO_CRP ;

// TODO: insert other include files here
#include <math.h>
#include <stdio.h>
// TODO: insert other definitions and declarations here
int adc_config(void);
uint16_t prevVal,curVal,errCnt;
uint16_t readADC();

int main(void)
{
        int i;
        errCnt = 0;
        const unsigned int led_state[] = {
                                    0x01, 0x03, 0x07, 0x0f,
                                    0x1f, 0x3f, 0x7f, 0xff
                                };
        LPC_GPIO2->FIODIR = 0x000000FF;
        adc_config();

        while(1)
        {
                i = readADC();
                //printf("i = %d",i);
                LPC_GPIO2->FIOSET = led_state[(i >> 9) & 7];
        }
        return 0 ;
}

int adc_config(void)
{
        LPC_SC->PCONP |= 1 << 12; // power for adc
        LPC_ADC->ADCR |= (1 << 5) | (1 << 21); // bit for ADC0.5 input and PDN mode is operational
        LPC_SC->PCLKSEL0 |= 0; //clock for ADC - adcclk = pclk/4 = 3Mhz
        LPC_PINCON->PINSEL3 |= (1 << 30) | (1 << 31); //activate adc function on pin P1.31
        //LPC_ADC->ADINTEN = 1 << 8; //enable interrupts for channel 0
        //NVIC_EnableIRQ(ADC_IRQn);
}

/*void ADC_IRQHandler(void)
{

}*/

uint16_t readADC()
{
        LPC_ADC->ADCR |= 1 << 24;// start conversion.
        while(!(LPC_ADC->ADGDR & (1 << 31))); // wait for completion of coversion
        curVal = (LPC_ADC->ADGDR >> 4) & 0x0fff;

        if(errCnt >= 3)
        {
                prevVal = curVal;
        }

        if(abs((curVal - prevVal) > 20))
        {
                curVal = prevVal;
                errCnt++;
        }
        else
        {
                errCnt = 0;
        }

        prevVal = curVal;
        return curVal;
}

Not sure if you actually used the processor user manual, or if you just looked at any blinky application.

But when you did find the FIOSET register - didn't you then also find any FIOCLR register?

By the way - I see you wrote a hysterese function to reduce problems with noise from the potentiometer. But why did you select a variable name errCnt? Where is the error?

Another thing - why is curVal a global variable? You give it a value the first thing you do in the readADC() function - and then you return the value of curVal - so no need to retain the value of it until next call...

OK, I did it. Now it works good :) LEDs turns off too :) I only added one line:

LPC_GPIO2->FIOCLR =~(led_state[(i >> 9) & 7]);

When I negate table's value and send it to FIOCLR register LEDs turns off.
I knew about this register, but as I said I have many habits from AVR...I forgot that, if I want to turn off LEDs I must write "1" to the bits of FIOCLR.

But AVRs also have SET and CLEAR registers for their port bits - don't they?!

In a previous post he mentioned ATmega32 so no, there is no set/clr.
There is only a direction , port and input read register (DDR, PORT,PIN)

Alex