Add day00/ex04

Author: ImHoppy

day00/ex04.c

@@ -0,0 +1,43 @@
+#include <avr/io.h>
+#include <util/delay.h>
+
+#define is_pressed(reg, pos) ((reg & (1 << pos)) == 0)
+
+void set_bit(volatile uint8_t *reg, uint8_t pos, uint8_t value) {
+	if (value == 0) return;
+	*reg |= (1 << pos);
+}
+
+uint8_t on_press(uint8_t state, uint8_t reg, uint8_t pos, uint8_t action) {
+	static uint8_t nb;
+
+	if (state == 0 && is_pressed(reg, pos)) {
+		_delay_ms(20);
+		state = 1;
+		nb += action;
+		nb %= 16;
+		// Clear all led
+		PORTB &= (0xFF << 3) & ~(1 << 4); // 0b1111 1000 & 0x1110 1111
+		set_bit(&PORTB, PIN0, nb & 1);
+		set_bit(&PORTB, PIN1, nb & 2);
+		set_bit(&PORTB, PIN2, nb & 4);
+		set_bit(&PORTB, PIN4, nb & 8);
+	}
+	if (state == 1 && !is_pressed(reg, pos)) {
+		_delay_ms(20);
+		state = 0;
+	}
+	return state;
+}
+int main() {
+
+	uint8_t sw1_pressed = 0;
+	uint8_t sw2_pressed = 0;
+
+	DDRB = 0xFF | (1 << PIN4);
+
+	while (1) {
+		sw1_pressed = on_press(sw1_pressed, PIND, 2, 1);
+		sw2_pressed = on_press(sw2_pressed, PIND, 4, -1);
+	}
+}