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94 lines
2.5 KiB
C
94 lines
2.5 KiB
C
#include <avr/io.h>
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#include <avr/interrupt.h>
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#include "adc.h"
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void adc_init()
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{
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ADMUX = 1 << REFS0 | 0 << REFS1; //Select external Vref
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//ADC Status Register A
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ADCSRA = 1 << ADEN //Enable ADC
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| 1 << ADIE //Enable ISR after conversion complete
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//| 1<<ADATE //Freerunning-Mode
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//| 1<<ADLAR //2 results bits are left aligned
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| 1 << ADPS2 //Set clock-prescaler to 128
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| 1 << ADPS1 | 1 << ADPS0;
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ADCSRA |= 1 << ADSC; //Start first Conversion for "warmup"
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}
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void set_ADC_Channel(uint8_t adr)
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{
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if (adr < 11)
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{
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ADMUX &= (0b11110000); //Clear MUX-Address
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ADMUX |= adr; //Set new MUX-Address
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}
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}
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ISR(ADC_vect)
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{
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//static uint8_t init[4] = {0,0,0,0};
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static uint8_t current_channel = 0;
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static uint16_t read_buffer[128];
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static uint8_t buffer_pos = 0;
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//Reading 10bit conversion result
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uint16_t ADC_reading = ADCL; //copy the first LSB bits
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ADC_reading |= ADCH << 8; //copy remaing byte
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read_buffer[buffer_pos] = ADC_reading;
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buffer_pos++;
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if(buffer_pos == (sizeof(read_buffer) / sizeof(read_buffer[0]))){
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uint32_t sum = 0;
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for(uint8_t i = 0; i < buffer_pos; i++){
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sum += read_buffer[i];
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}
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//convert to temperature
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sum /= 3;
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switch(current_channel){
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case 0:
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temp_values[3] = sum/buffer_pos;
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break;
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case 1:
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temp_values[0] = sum/buffer_pos;
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break;
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case 2:
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temp_values[1] = sum/buffer_pos;
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break;
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case 3:
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temp_values[2] = sum/buffer_pos;
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break;
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}
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buffer_pos = 0;
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current_channel++;
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if(current_channel == 4)
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current_channel = 0;
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set_ADC_Channel(current_channel);
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}
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ADCSRA |= (1 << ADSC); //Start next conversion
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//TODO write non broken adc code
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//if(adc_buf[current_channel].position == BUFFER_SIZE-1){
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// //if(init[current_channel]){
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// //float tmp = (99*adc_avrg[current_channel]) + get_buffer_mean(&adc_buf[current_channel]);
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// //tmp /= 100;
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// adc_avrg[current_channel] = get_buffer_mean(&adc_buf[current_channel]);
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// //}
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// //else{
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// // adc_avrg[current_channel] = get_buffer_mean(&adc_buf[current_channel]);
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// // init[current_channel]=0;
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// //}
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//}
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}
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