adc.c

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#include <avr/io.h>
#include <stdio.h>
#include <util/delay.h>
 
#include "adc.h"
#include "log.h"
 
LOG_MODULE_DEFINE("ADC");
 
#define ADC_BASE_ADR ((volatile uint8_t *)0x1000) // Adress offset for ADC
 
void ADC_init(void) {
 
  // XMEM controls the ADC and is enabled elsewhere (xmem_init())
  // Do NOT touch DDR/PORTA (PORTA is the external data bus and is handeled
  // trough writing to and reading to xmem) No need to set up PD6/PD7; XMEM
  // controls WR/RD automatically when we read or write to memory allocted to
  // the ADC
}
 
void ADC_start_conv(void) {
 
  // Write to any adress on ADC to trigger WR
  *ADC_BASE_ADR = 0x00;
  // Delay to ensure ADC conversion is done, checking BUSY pin insead.
  while ((PORTD & PD4)) {
  }
}
 
uint8_t ADC_read_ch(void) {
 
  // Read from any adress in ADC allocated memory adressarea to
  return *ADC_BASE_ADR;
}
 
void ADC_read_all(struct ADC_meas *output) {
 
  ADC_start_conv();
 
  volatile uint8_t adc_value[4];
 
  // Send a pulse then read for each channel
  for (uint8_t i = 0; i < 4; i++) {
    _delay_ms(5);
    adc_value[i] = ADC_read_ch();
    output->channel[i] = adc_value[i];
  }
}
 
/*
void ADC_test(void) {
 
  struct ADC_meas data;
 
  ADC_read_all(&data);
 
  printf("--ADC Test--\n\r");
  printf("CH0=%3d  CH1=%3d  CH2=%3d  CH3=%3d\r\n", data.channel[0] - 128,
         data.channel[1] - 128, data.channel[2] - 128, data.channel[3] - 128);
 
  _delay_ms(100);
}
*/