Files
42_EXT_03_42chips/module01/ex03/main.c
2025-03-06 16:23:18 +01:00

129 lines
3.8 KiB
C

#include <avr/io.h>
#include <util/delay.h>
// stringify
#define STRINGIFY_HELPER(x) #x
#define STRINGIFY(x) STRINGIFY_HELPER(x)
// concatenate
#define CONCAT_HELPER(x, y) x ## y
#define CONCAT(x, y) CONCAT_HELPER(x, y)
// get argument
#define ARG_1(v1, v2) v1
#define ARG_2(v1, v2) v2
#define GET_PORT(args) ARG_1 args
#define GET_BIT(args) ARG_2 args
// actions on registers
#define SET(register, bit) register |= 1 << bit
#define CLEAR(register, bit) register &= ~(1 << bit)
#define TEST(register, bit) register & 1 << bit
#define TOGGLE(register, bit) register ^= 1 << bit
// actions on elements
#define SET_ELEM(elem) SET(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define CLEAR_ELEM(elem) CLEAR(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TEST_ELEM(elem) TEST(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_ELEM(elem) TOGGLE(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define MODE_OUTPUT(elem) SET(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define MODE_INPUT(elem) CLEAR(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_PIN(elem) SET(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem))
#define TEST_PIN(elem) (TEST(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem)))
#define IS_PIN_SET(elem) (TEST_PIN(elem) == 0)
#define IS_PIN_CLEAR(elem) (TEST_PIN(elem) == 1)
// bits
#define D1 0
#define D2 1
#define D3 2
#define D4 4
#define SW1 2
#define SW2 4
// elements (port, bit)
#define LED1 (B, D1)
#define LED2 (B, D2)
#define LED3 (B, D3)
#define LED4 (B, D4)
#define BUTTON1 (D, SW1)
#define BUTTON2 (D, SW2)
// TIME
#define PRESCALE_VALUE 1024
#if (PRESCALE_VALUE == 1)
#define PRESCALE_SET (1 << CS10)
#elif (PRESCALE_VALUE == 8)
#define PRESCALE_SET (1 << CS11)
#elif (PRESCALE_VALUE == 64)
#define PRESCALE_SET (1 << CS10) | (1 << CS11)
#elif (PRESCALE_VALUE == 256)
#define PRESCALE_SET (1 << CS12)
#elif (PRESCALE_VALUE == 1024)
#define PRESCALE_SET (1 << CS10) | (1 << CS12)
#endif
#define TIME_MS(ms) (((F_CPU / PRESCALE_VALUE) * ms) / 1000)
#define PERIOD 1000
#define DUTY_CYCLE 10
#define PERCENT(percent, period) (((float)percent / 100) * period)
// END MACROS
typedef struct {
int duty_cycle;
int max;
int min;
} IncrementParams;
void increment_duty_cycle(void *param) {
IncrementParams *params = (IncrementParams *)param;
if(params->duty_cycle < params->max) {
params->duty_cycle += 10;
}
OCR1A = TIME_MS(PERCENT(params->duty_cycle, PERIOD));
}
void decrement_duty_cycle(void *param) {
IncrementParams *params = (IncrementParams *)param;
if(params->duty_cycle > params->min) {
params->duty_cycle -= 10;
}
OCR1A = TIME_MS(PERCENT(params->duty_cycle, PERIOD));
}
void on_press(int bit, void (*action)(void*), void *params) {
if ((TEST(PIND, bit)) == 0) {
action(params);
_delay_ms(20);
while ((TEST(PIND, bit)) == 0) {
continue;
}
_delay_ms(20);
}
}
int main() {
int duty_cycle = DUTY_CYCLE;
int max = 100;
int min = 0;
IncrementParams params = {duty_cycle, max, min};
MODE_OUTPUT(LED2);
SET(TCCR1A, WGM11); // Table 16-4 : set timer in Fast PWM (Pulse With Modulation) mode with TOP = ICR1 (Mode 14)
SET(TCCR1B, WGM12);
SET(TCCR1B, WGM13);
SET(TCCR1A, COM1A1); // Table 16-2 : non-inverting mode, the LED will be ON for DUTY_CYCLE% of the time (CLEAR OC1A on compare match, SET OC1A at BOTTOM)
ICR1 = TIME_MS(PERIOD); // Table 16-4 : set the period (compare TOP value)
OCR1A = TIME_MS(PERCENT(DUTY_CYCLE, PERIOD)); // 16.9.3 : set the duty cycle to DUTY_CYCLE% of the time -> OC1A (alternate function of PORTB1, aka LED2) is cleared when TCNT1 (the counter value) equals OCR1A
TCCR1B |= (PRESCALE_SET); // start the timer with the prescaler
while(1) {
on_press(SW1, increment_duty_cycle, &params);
on_press(SW2, decrement_duty_cycle, &params);
}
}