X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=tinyboard.git;a=blobdiff_plain;f=projects%2Fled-blinker%2Fmain.c;fp=projects%2Fled-blinker%2Fmain.c;h=70491edcf029f30f9fa1bacded8ce4ed192cf7f2;hp=0000000000000000000000000000000000000000;hb=c4ebe9bfc347f0acaa1319e982d9a999eb9063cb;hpb=85a869857e315a5f4b4b20dee7d44429c1d0cc1c

diff --git a/projects/led-blinker/main.c b/projects/led-blinker/main.c
new file mode 100644
index 0000000..70491ed
--- /dev/null
+++ b/projects/led-blinker/main.c
@@ -0,0 +1,134 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/sleep.h>
+#include <avr/power.h>
+
+/*
+ * Overview:
+ * three LEDs:
+ * PB1/OC1A     yellow
+ * PB2          yellow
+ * PB4/OC1B     red
+ */
+
+static void init()
+{
+	DDRB |= _BV(PB1) | _BV(PB2) | _BV(PB4);
+
+	// PWM setup, use T/C 1
+	TCCR1 = _BV(CS10)	// clock at CLK/1
+		| _BV(PWM1A)	// OCR1A in PWM mode
+		| _BV(COM1A1);	// clear on compare match
+	GTCCR = _BV(PWM1B)	// OCR1B in PWM mode
+		| _BV(COM1B1); // clear on compare match)
+
+	OCR1C = 255;
+	OCR1A = 0;
+	OCR1B = 0;
+}
+
+
+static unsigned char levels[] = {
+	0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 255
+};
+#define N_LEVELS (sizeof(levels)/sizeof(levels[0]))
+
+static void led_set(unsigned char led, unsigned char val)
+{
+	switch (led) {
+	case 0:
+		OCR1A = val < N_LEVELS ? levels[val] : levels[N_LEVELS-1];
+		break;
+	case 1:
+		if (val) {
+			PORTB |= _BV(PB2);
+		} else {
+			PORTB &= ~_BV(PB2);
+		}
+		break;
+	case 2:
+		OCR1B = val < N_LEVELS ? levels[val] : levels[N_LEVELS-1];
+		break;
+	}
+}
+
+static unsigned char rand[] = {
+193, 33, 133, 97, 139, 225, 40, 105, 110, 238, 57, 250, 26, 221, 166, 247, 138, 23, 107, 122, 154, 33, 201, 66, 154, 78, 137, 198, 86, 232, 38, 182, 16, 198, 73, 231, 58, 114, 58, 105,
+};
+#define N_RAND (sizeof(rand)/sizeof(rand[0]))
+
+static void led0()
+{
+	static unsigned char r, l, exp;
+
+again:
+	if (l == exp) {
+		r++;
+		if (r > N_RAND-7)
+			r = 0;
+		exp = rand[r] >> 4;
+		if (exp >= N_LEVELS-4)
+			goto again;
+	}
+
+	if (l < exp) {
+		l++;
+	} else if (l > exp) {
+		l--;
+	}
+
+	led_set(0, l);
+}
+
+static void led1()
+{
+	static unsigned char r;
+	unsigned char exp;
+
+	led_set(1, 1);
+#if 0
+again:
+	r++;
+	if (r > N_RAND)
+		r = 0;
+	exp = rand[r];
+
+	led_set(1, ((exp >> 3) & 1) ^ ((exp >> 5) & 1));
+#endif
+}
+
+static void led2()
+{
+	static unsigned char r, l, exp;
+
+again:
+	if (l == exp) {
+		r++;
+		if (r > N_RAND)
+			r = 0;
+		exp = rand[r] & 0xF;
+		if (exp >= N_LEVELS)
+			goto again;
+	}
+
+	if (l < exp) {
+		l++;
+	} else if (l > exp) {
+		l--;
+	}
+
+	led_set(2, l);
+}
+
+int main(void)
+{
+	init();
+
+	while (1) {
+		led0();
+		led1();
+		led2();
+		_delay_ms(40);
+	}
+
+}