Subversion Repositories HomeAutomation

/*********************************************************************
 *
 *   Functions for reading ADC
 *
 *********************************************************************
 * FileName:        $HeadURL: https://svn.auml.se/svn/HomeAutomation/trunk/EmbeddedSoftware/PIC/Include/adc.c $
 * Last changed:    $LastChangedDate: 2006-11-20 21:31:03 +0100 (Mon, 20 Nov 2006) $
 * By:              $LastChangedBy: johboh $
 * Revision:        $Revision: 139 $
 ********************************************************************/
#include <adc.h>

#ifdef USE_ADC

static unsigned long TEMP_VALUE;
static unsigned int TEMP_COUNT;

BOOL TEMP_DONE = FALSE;

/*
*   Function: adcInit
*
*   Input:  True or false to use external voltage reference or not. portCfg is portconfiguration.
*   Output: none.
*   Pre-conditions: none
*   Affects: none.
*   Depends: none.
*/
void adcInit(BOOL useExtRef,BYTE portCfg)
{
    // Setup ADC to use low interrupt prior and external ref or not.

    ADCON1 = 0b00000000 | ((1 & useExtRef)<<4) | (0xF & portCfg);
    ADCON0 = 0b00000000;
    ADCON2 = 0b10101011;
    //useExtRef
    ADCON0bits.ADON = 1;
    PIR1bits.ADIF = 0;
    PIE1bits.ADIE = 1;
    IPR1bits.ADIP = 0; // Low priority
}


/*
*   Function: adcISR
*
*   Input:  ADC interrupt rotune. Need to be called from LOW ISR.
*   Output: none.
*   Pre-conditions: none
*   Affects: none.
*   Depends: none.
*/
void adcISR(void)
{
    if (PIE1bits.ADIE && PIR1bits.ADIF)
    {
        PIR1bits.ADIF = 0;

        TEMP_VALUE+=((int)ADRESH)<<8 | ADRESL;
        TEMP_COUNT++;

        if (TEMP_COUNT>=TEMP_SAMPLES)
        {
            TEMP_VALUE = TEMP_VALUE/TEMP_COUNT;
            TEMP_DONE = TRUE;
        }
        else
        {
            Delay10TCYx(100);
            ADCON0bits.GO = 1;
        }

    }
}


/*
*   Function: adcConvert
*
*   Input:  Channel to start convert. Between 0 and 15
*   Output: none.
*   Pre-conditions: none
*   Affects: none.
*   Depends: none.
*/
BOOL adcConvert(BYTE channel)
{
    if (channel>15) return FALSE;

    TEMP_VALUE = 0;
    TEMP_COUNT = 0;

    ADCON0 = (channel << 2)  | (ADCON0 & 0b11000011);

    TEMP_DONE = FALSE;

    ADCON0bits.GO = 1;

    return TRUE;
}


/*
*   Function: adcRead
*
*   Input:  none.
*   Output: Raw read data.
*   Pre-conditions: none
*   Affects: none.
*   Depends: none.
*/
int adcRead(void)
{
    TEMP_DONE=FALSE;
    return TEMP_VALUE;
}


/*
*   Function: temperatureRead
*
*   Input:  none.
*   Output: XX.Y C, where tenth is XX and decimal is Y
*   Pre-conditions: none
*   Affects: none.
*   Depends: none.
*/
void temperatureRead(signed char *tenth, BYTE *decimal) 
{
    // assuming 2.5V ref and TC47
    signed int i = 0, v11,v01,tfloat;

    tfloat =((TEMP_VALUE * 39)>>4) - 499;
    
    v11 = tfloat/10;
    v01 = tfloat-v11*10;

         if (v01>=0 && v01<=2) v01 = 0;
    else if (v01>=3 && v01<=7) v01 = 5;
    else  { v01 = 0; v11++;}

    tenth = (signed char *)v11;
    decimal = (BYTE *)v01;


        TEMP_DONE=FALSE;
}


/*
*   Function: adcDone
*
*   Input:  none.
*   Output: If adc convertion is done or not.
*   Pre-conditions: none
*   Affects: none.
*   Depends: none.
*/
BOOL adcDone(void)
{
    return TEMP_DONE;
}

#endif