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m05e02 ok, calibration random

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This commit is contained in:
hugogogo
2025-03-15 15:49:22 +01:00
parent e33261846b
commit 8365a79837
4 changed files with 31 additions and 27 deletions
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12
.vscode/settings.json vendored
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@@ -2,16 +2,6 @@
"editor.insertSpaces": false,
"editor.detectIndentation": false,
"files.associations": {
"io.h": "c",
"delay.h": "c",
"interrupt.h": "c",
"timer.h": "c",
"usart.h": "c",
"utils.h": "c",
"bitmanip.h": "c",
"rush_header.h": "c",
"twi.h": "c",
"header.h": "c",
"adc.h": "c"
"header.h": "c"
}
}

34
module05/ex02/adc.c
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@@ -3,30 +3,40 @@
// 24.2 : The ADC generates a 10-bit result which is presented in the ADC Data Registers, ADCH and ADCL
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 |= (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
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 & 0b00001111); // Table 24-4 : Select ADC channel 0
ADCSRB = ADC_TRIGGER_TIMER_1_COMPARE_B; // Table 24-6 : ADC Auto Trigger Source
ADMUX = (ADMUX & 0b11110000) | (adc_channel & 0b00001111); // Table 24-4 : Select ADC channel 0
}
uint16_t calibrate_temperature(uint16_t value, uint8_t speed) { // 24.8 : Temperature Measurement
// calibration random
uint16_t offset = (540 - (25*speed));
value = (value - offset) / speed;
return value;
}
void adc_print_dec(uint16_t value) {
if (adc_channel == ADC_THERMISTOR) {
value = calibrate_temperature(value, 5);
}
char buffer[17] = {0};
uint16_to_string(value, buffer);
uart_printstr(buffer);
}
ISR(ADC_vect) { // Table 12-6 : interrupt vector for ADC Conversion Complete
uint16_t value = ADC; // 24.9.3.2 : read ADC 16 bits precision
ISR(ADC_vect) { // Table 12-6 : interrupt vector for ADC Conversion Complete
uint16_t value = ADC; // 24.9.3.2 : read ADC 16 bits precision
adc_print_dec(value);
adc_channel = (adc_channel + 1) % 3; // loop through channels
ADMUX = (ADMUX & 0b11110000) | (adc_channel & 0b1111); // Table 24-4 : Select ADC channel
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
ADCSRA |= (1 << ADSC); // 24.9.2 : start next conversion
} else {
uart_printstr("\r\n");
}

6
module05/ex02/header.h
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@@ -28,7 +28,8 @@ void int_to_hex_string(uint64_t value, char *out, uint8_t num_digits);
void uint16_to_string(uint16_t value, char *out);
// adc.c
void adc_init(uint8_t prescaler_value);
uint16_t adc_read(uint8_t channel);
uint16_t calibrate_temperature(uint16_t value, uint8_t speed);
void adc_print_dec(uint16_t value);
// uart.c
void uart_init();
void uart_tx(char c);
@@ -38,5 +39,8 @@ void uart_printstr_endl(const char* str);
//
// MACROS
//
#define ADC_POTENTIOMETER 0
#define ADC_PHOTORESISTOR 1
#define ADC_THERMISTOR 2
#endif // HEADER_H

6
module05/ex02/main.c
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@@ -12,14 +12,14 @@
// - P = 64 -> Fadc = 16,000,000 / 64 = 250,000 = 250KHz -> OK
// - P = 128 -> Fadc = 16,000,000 / 128 = 125,000 = 125KHz -> OK
#define ADC_PRESCALER 128 // Table 24-5 : can only be 2, 4, 8, 16, 32, 64, or 128
#define ADC_PRESCALER 128 // Table 24-5 : can only be 2, 4, 8, 16, 32, 64, or 128
volatile uint8_t adc_channel = 0; // Table 14-6 : alternate function for RV1 on PC0 -> ADC0, LDR on PC1 -> ADC1, NTC on PC2 -> ADC2 ...
volatile uint8_t adc_channel = ADC_POTENTIOMETER; // Table 14-6 : alternate function for RV1 on PC0 -> ADC0, LDR on PC1 -> ADC1, NTC on PC2 -> ADC2 ...
// read 3 analog values at 10 bits and print them in uart as decimal : potentiometer RV1 (Variable Resistor), photoresistor LDR (Light Dependent Resistor), thermistor NTC (Negative Temperature Coefficient)
int main() {
char buffer[4];
SREG |= ENABLE_GLOBAL_INTERRUPT; // 7.3.1 : Status Register, bit 7 : I – Global Interrupt Enable
SREG |= ENABLE_GLOBAL_INTERRUPT; // 7.3.1 : Status Register, bit 7 : I – Global Interrupt Enable
uart_init();
adc_init(ADC_PRESCALER);