a2d.c

/*! \file a2d.c \brief Analog-to-Digital Converter Driver for LPC2000. */
//*****************************************************************************
//
// File Name    : 'a2d.c'
// Title        : Analog-to-Digital Converter Driver for LPC2000
// Author       : Pascal Stang - Copyright (C) 2006
// Created      : 2006.04.09
// Revised      : 2006.04.15
// Version      : 0.1
// Target MCU   : LPC2000 ARM processors
// Editor Tabs  : 4
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

// system includes
#include "lpc2000.h"
#include "global.h"

// local includes
#include "a2d.h"

void a2dInit(void)
{
    // set ADC to:
    // - CLKDIV as appropriate
    // - single conversion mode
    // - 10-bit accuracy
    // - powered-up
    ADCR = (((PCLK/4500000))<<8) | ADCR_CLKS_10BIT | ADCR_PDN;
}

int a2dConvert(int channel)
{
    uint32_t result=0;

    // start conversion on requested channel
    ADCR &= ~(ADCR_SEL_MASK|ADCR_START_NOW);    // clear previous channel and conversion
    ADCR |= (1<<channel);   // select new channel
    ADCR |= ADCR_START_NOW; // start conversion

    // wait for end-of-conversion
    while(!(result & ADDR_DONE)) result = ADDR;

    // return data
    return (result & ADDR_VALUE_MASK)>>6;
}

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