app/eb_ebb/adc.c

   1 #include <lpc21xx.h>                          // LPC21XX Peripheral Registers
   2 #include <types.h>
   3 #include "adc.h"
   4 #include <stdlib.h>
   5
   6
   7 #define ADCCH0 22       ///< ADC0 value for PINSEL
   8 #define ADCCH1 24       ///< ADC1 value for PINSEL
   9 #define ADCCH2 26       ///< ADC2 value for PINSEL
  10 #define ADCCH3 28       ///< ADC3 value for PINSEL
  11
  12 /**
  13  *  ADC ISR routine. This routine reads selected ADC value and
  14  *  multiplies it by #ADC_MUL and adds #ADC_OFFSET to calculate the
  15  *  volage (3.25mV/div).  After this reading the next ADC channel is
  16  *  set up for measuring.
  17  */
  18 void adc_isr(void) __attribute__ ((interrupt));
  19 void adc_isr(void)
  20 {
  21         unsigned char chan =0;
  22         unsigned int val =0;
  23
  24
  25         chan = (char) ((ADDR>>24) & 0x07);
  26         val = (((((ADDR >> 6) & 0x3FF) * ADC_MUL + ADC_OFFSET) + adc_val[chan]) >> 1) ;
  27
  28
  29
  30         adc_val[chan] = val;
  31
  32         ADCR &= ~(ADC_CR_START_OFF_m);
  33
  34
  35         switch(chan)
  36         {
  37                 case 0:
  38                         ADCR = ((ADC_CR_ADC1_m) | (ADC_CR_CLKS_11_m) | (ADC_CR_PDN_ON_m) | (ADC_CR_START_NOW_m) | (20*ADC_CR_CLK_DIV_1_m));
  39                         break;
  40
  41                 case 1:
  42                         ADCR = ((ADC_CR_ADC2_m) | (ADC_CR_CLKS_11_m) | (ADC_CR_PDN_ON_m) | (ADC_CR_START_NOW_m) | (20*ADC_CR_CLK_DIV_1_m));
  43                         break;
  44
  45                 case 2:
  46                         ADCR = ((ADC_CR_ADC3_m) | (ADC_CR_CLKS_11_m) | (ADC_CR_PDN_ON_m) | (ADC_CR_START_NOW_m) | (20*ADC_CR_CLK_DIV_1_m));
  47                         break;
  48
  49                 case 3:
  50                         ADCR = ((ADC_CR_ADC0_m) | (ADC_CR_CLKS_11_m) | (ADC_CR_PDN_ON_m) | (ADC_CR_START_NOW_m) | (20*ADC_CR_CLK_DIV_1_m));
  51                         break;
  52         }
  53
  54          VICVectAddr = 0;
  55
  56 }
  57
  58 /**
  59  *  Inicializes ADC service for all ADC (4) channels and installs ISR routine to VIC.
  60  *   Automaticly starts the conversion of first channel on given conversion frequency.
  61  */
  62 void init_adc(unsigned rx_isr_vect)
  63 {
  64
  65         PINSEL1 |= ((PINSEL_1 << ADCCH0) | (PINSEL_1 << ADCCH1) | (PINSEL_1 << ADCCH2) | (PINSEL_1 << ADCCH3));
  66
  67         ((uint32_t*)&VICVectCntl0)[rx_isr_vect] = 0x32;
  68         ((uint32_t*)&VICVectAddr0)[rx_isr_vect] = (unsigned) adc_isr;
  69         VICIntEnable = 0x40000;
  70
  71         ADCR = ((ADC_CR_ADC0_m) | (ADC_CR_CLKS_11_m) | (ADC_CR_PDN_ON_m) | (ADC_CR_START_NOW_m) | (ADC_VPB_DIV*ADC_CR_CLK_DIV_1_m));
  72 }