42/42_EXT_03_42chips
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

reorganize files

Browse Source
This commit is contained in:
hugo LAMY
2025-03-14 19:47:02 +01:00
committed by hugogogo
parent 0e87d41c08
commit b12eff7ede
4 changed files with 29 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
module05/ex00/adc.c
View File

@@ -14,13 +14,19 @@ 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
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, (Table 14-6 : alternate function for RV1 on PC0 -> ADC0)
}
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)
ADMUX |= (1 << ADLAR); // 24.9.1 : enable left adjust result
ADCSRA |= (1 << ADSC); // 24.9.2 : Start conversion, ADSC: ADC Start Conversion
while (ADCSRA & (1 << ADSC)); // Wait for completion
return ADCH; // 24.9.3 : ADC updated only when ADCH is read, not ADCL, so for 8 bits precision uses left adjust result to only read ADCH
void adc_print_hex(uint8_t value) {
char buffer[3] = {0};
int_to_hex_string(value, buffer, 2);
uart_printstr_endl(buffer);
}
ISR(ADC_vect) { // Table 12-6 : interrupt vector for ADC Conversion Complete
uint16_t value = ADC;
adc_print_hex(value);
}

3
module05/ex00/header.h
View File

@@ -16,6 +16,9 @@
// PROTOTYPES
//
// main.c
// timer.c
void timer_1B_init();
// math.c
void int_to_hex_string(uint64_t value, char *out, uint8_t num_digits);
// adc.c
void adc_init(uint8_t prescaler_value);

8
module05/ex00/main.c
View File

@@ -14,13 +14,7 @@
#define ADC_PRESCALER 64 // Table 24-5 : can only be 2, 4, 8, 16, 32, 64, or 128
void int_to_hex_string(uint64_t value, char *out, uint8_t num_digits) { // num_digits : number of digit of the output, ex 2 for 3FF (1023) -> FF
for (uint8_t i = 0; i < num_digits; ++i) {
uint8_t shift = (num_digits - 1 - i) * 4;
out[i] = INT_TO_HEX_CHAR((value >> shift) & 0x0F);
}
out[num_digits] = '\0';
}
volatile uint8_t adc_channel = 0;
// description
int main() {

12
module05/ex00/timer.c Normal file
View File

@@ -0,0 +1,12 @@
#include "header.h"
// Set up Timer1 in CTC mode to trigger every 20ms
// With 16MHz clock and prescaler of 8, and OCR1A = 39999:
// 16MHz/8/40000 = 50Hz = 20ms period
void timer_1B_init() {
TCCR1A = 0; // Normal operation, OC1A/OC1B disconnected
TCCR1B = (1 << WGM12) | (1 << CS11); // CTC mode, prescaler = 8
OCR1A = 39999; // Compare match value for 20ms
TIMSK1 = (1 << OCIE1B); // Enable Timer1 Compare B Match Interrupt
}