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m05e01 done

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hugogogo
2025-03-15 13:17:46 +01:00
parent 2fd1d7d931
commit 5904f7c5e0
4 changed files with 67 additions and 36 deletions
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43
module05/ex01/adc.c
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@@ -1,25 +1,34 @@
#include "header.h"
// Table 14-6. Port C Pins Alternate Functions
// - PC0 -> ADC0 (ADC Input Channel 0)
// -> PCINT8 (Pin Change Interrupt 8)
//
// 24.2 : The ADC generates a 10-bit result which is presented in the ADC Data Registers, ADCH and ADCL
//
// START A CONVERSTION in single conversion mode :
// - disabling the Power Reduction ADC bit, PRADC
// - writing a logical one to the ADC Start Conversion bit, ADSC
void adc_init(uint8_t prescaler_value) {
ADMUX = (1 << REFS0); // Table 24-3 : set voltage reference, AVCC with external capacitor at AREF pin
ADCSRA = (1 << ADEN); // 24.9.2 : enable ADC
ADCSRA |= ADC_PRESCALE_SET(prescaler_value); // Table 24-5 : prescaler ADC
ADMUX = (1 << REFS0); // Table 24-3 : set voltage reference, AVCC with external capacitor at AREF pin
ADCSRA = (1 << ADEN); // 24.9.2 : enable ADC
ADCSRA |= (1 << ADATE); // 24.9.2 : enable Auto Trigger -> it will start a conversion on the selected channel in ADMUX when the selected source (in ADCSRB) is triggered
ADCSRA |= (1 << ADIE); // 24.9.2 : enable ADC Interrupt
ADCSRA |= ADC_PRESCALE_SET(prescaler_value); // Table 24-5 : prescaler ADC
ADCSRB = ADC_TRIGGER_TIMER_1_COMPARE_B; // Table 24-6 : ADC Auto Trigger Source
ADMUX = (ADMUX & 0b11110000) | (adc_channel & 0b1111); // Table 24-4 : Select ADC channel 0
}
uint16_t adc_read(uint8_t channel) {
CLEAR(PRR, PRADC); // 24.3 : ensure power reduction is disabled for ADC, (10.11.3 : PRR – Power Reduction Register)
ADMUX = (ADMUX & 0b11110000) | (channel & 0b1111); // Table 24-4 : Select ADC channel, (Table 14-6 : alternate function for RV1 on PC0 -> ADC0)
ADCSRA |= (1 << ADSC); // 24.9.2 : Start conversion, ADSC: ADC Start Conversion
while (ADCSRA & (1 << ADSC)); // Wait for completion
return ADC;
void adc_print_hex(uint8_t value) {
char buffer[3] = {0};
int_to_hex_string(value, buffer, 2);
uart_printstr(buffer);
}
ISR(ADC_vect) { // Table 12-6 : interrupt vector for ADC Conversion Complete
uint16_t value = ADC;
adc_print_hex(value);
adc_channel = (adc_channel + 1) % 3; // loop through channels
ADMUX = (ADMUX & 0b11110000) | (adc_channel & 0b1111); // Table 24-4 : Select ADC channel
if (adc_channel != 0) {
uart_printstr(", ");
ADCSRA |= (1 << ADSC); // 24.9.2 : start next conversion
} else {
uart_printstr("\r\n");
}
}