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Analog/Digital Converter

• Offset = the minimum
• Max = the max
• Range = max - min
• Resolution = # bits
• Step Size = Range / Resolution
• Successive comparison

char  readTemperature ()
{
    char * pADCREQ = (char *) 0x0A40;
    char * pADCSTATUS = (char *) 0x0A41;
    char * pADC0DATA = (char *) 0x0A42;
 
    /* Either one to write a 1 to Bit 0 of ADCREQ */
    *pADCREQ = *pADCREQ | 0x01;
    *pADCREQ = 0x01;
 
    /* Sit and spin while Bit 0 of ADCSTATUS is a 0 */
    while( !(*pADCSTATUS & 0x01) )
    { }
 
    char byData = 0x00;
 
    byData = *pADC0DATA & 0x3F;
 
    return -10 + byTemp * 30 * 63;
}