X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=tinyboard.git;a=blobdiff_plain;f=projects%2Frgb-led-string%2Fmain.c;h=bd923612f57f30dd0cba6093daaf2e02894caee2;hp=4c82f48b8f2bed6b97f3c74e471495b60aec8d56;hb=5013d75921e37f1df3034f0d2ed39ddecb718d67;hpb=616f20d134e94462b5920a2f93be54cdb9fe74e0

diff --git a/projects/rgb-led-string/main.c b/projects/rgb-led-string/main.c
index 4c82f48..bd92361 100644
--- a/projects/rgb-led-string/main.c
+++ b/projects/rgb-led-string/main.c
@@ -4,17 +4,290 @@
 
 #include "rgbstring.h"
 
+static unsigned char jiffies;
+
+// #define CHRISTMAS_TREE 1
+
+#define rgb_return(r, g, b)	do { send_rgb((r), (g), (b)); return 1; } while(0)
+
+#define VERT_SIZE 47
+
+/* RNG from ADC noise */
+static unsigned char rand_pool[8], rand_pool_off, prev_bit, rand_pool_out;
+
+static void init_rng()
+{
+	ADCSRA |= _BV(ADEN) | _BV(ADPS2) | _BV(ADPS1); // enable, clk/64
+	ADMUX = _BV(REFS1) | _BV(MUX0) | _BV(MUX3); // 1.1V, PB5:PB5, gain 20
+	DIDR0 = _BV(ADC0D);
+	ADCSRA |= _BV(ADIE) | _BV(ADSC);
+	rand_pool_off = 0;
+	prev_bit = 0;
+}
+
+static unsigned char rand() {
+	unsigned char rv = 0;
+
+	rv = rand_pool[rand_pool_out];
+	rand_pool_out++;
+	if (rand_pool_out >= sizeof(rand_pool))
+		rand_pool_out = 0;
+
+	return rv;
+}
+
+ISR(ADC_vect) {
+	ADCSRA |= _BV(ADSC);
+	if ((rand_pool_off & 1) == 0) { // first bit of the pair
+		prev_bit = ADCW & 1;
+		rand_pool_off++;
+	} else {
+		unsigned char bit = ADCW & 1;
+		if (bit == prev_bit) { // whitening fail: try again
+			rand_pool_off--;
+			return;
+		}
+
+		if (bit) {
+			rand_pool[rand_pool_off >> 4]
+				^= 1 << ((rand_pool_off >> 1) & 7);
+		}
+
+		rand_pool_off++;
+		if (rand_pool_off >= 16*sizeof(rand_pool))
+			rand_pool_off = 0;
+	}
+}
+
+/* up and down running stars at the beginning/end of the strip */
+static unsigned char updown_star, updown_star0, updown_down, updown_bright;
+
+static void updown_star_init()
+{
+	updown_star0 = 0;
+	updown_down = 1;
+}
+
+static void updown_star_frame()
+{
+	if (updown_star0 == 0) {
+		updown_star0 = STRIP_SIZE-VERT_SIZE-8;
+		updown_down = 0;
+	} else if (updown_star0 == STRIP_SIZE + 8) {
+		updown_star0 = VERT_SIZE+7;
+		updown_down = 1;
+	} else if (updown_star0 <= VERT_SIZE + 8) {
+		updown_star0--;
+	} else if (updown_star0 >= STRIP_SIZE-VERT_SIZE-8) {
+		updown_star0++;
+	}
+
+	if (updown_down && updown_star0 < 8) {
+		updown_star = 0;
+		updown_bright = 1 << updown_star0;
+	} else if (updown_down) {
+		updown_star = updown_star0 - 8;
+		updown_bright = 128;
+	} else if (updown_star0 < STRIP_SIZE-VERT_SIZE) {
+		updown_star = STRIP_SIZE-VERT_SIZE;
+		updown_bright = 1 << (STRIP_SIZE-VERT_SIZE-updown_star0);
+	} else {
+		updown_star = updown_star0;
+		updown_bright = 1;
+	}
+}
+
+static unsigned char updown_star_pixel(unsigned char pos)
+{
+	if (pos >= VERT_SIZE && pos < STRIP_SIZE-VERT_SIZE)
+		return 0;
+
+	if (pos == updown_star) {
+		send_rgb(updown_bright, updown_bright, updown_bright);
+		if (updown_down) {
+			updown_bright >>= 1;
+			if (updown_bright)
+				updown_star++;
+		} else {
+			updown_bright <<= 1;
+			if (updown_bright)
+				updown_star++;
+		}
+		return 1;
+	}
+
+	return 0;
+}
+
+/* down running stars at the beginning/end of the strip */
+static unsigned char down_star, down_star0, down_bright;
+
+static void down_star_init()
+{
+	down_star0 = STRIP_SIZE;
+}
+
+static void down_star_frame()
+{
+	if (down_star0 == 0) {
+		down_star0 = STRIP_SIZE;
+	} else {
+		down_star0--;
+	}
+
+	if (down_star0 < 8) {
+		down_star = 0;
+		down_bright = 1 << down_star0;
+	} else {
+		down_star = down_star0;
+		down_bright = 128;
+	}
+}
+
+static unsigned char down_star_pixel(unsigned char pos)
+{
+	if (pos == down_star) {
+		send_rgb(down_bright, down_bright, down_bright);
+		down_bright >>= 1;
+		if (down_bright)
+			down_star++;
+		return 1;
+	}
+
+	return 0;
+}
+
+/* middle stars */
+
+static unsigned char midstar_pos0, midstar_pos, midstar_bright, midstar_color;
+
+static void midstar_init()
+{
+	midstar_pos0 = STRIP_SIZE/2;
+	midstar_color = 0;
+}
+
+static unsigned int slow_dim[] = {
+	255, 182, 130, 92, 66, 47, 33, 24, 17, 12, 8, 6, 4, 3, 2, 1,
+};
+
+static void midstar_frame()
+{
+	unsigned char phase = (jiffies) & 0x1F;
+
+	midstar_bright = phase & 0x10 ? slow_dim[phase & 0x0F]
+		: slow_dim[15-(phase & 0x0F)];
+
+	if (!phase) {
+		unsigned char c = rand();
+#ifdef CHRISTMAS_TREE
+		midstar_pos0 = 2 + (c % (STRIP_SIZE - 4));
+#else
+		midstar_pos0 -= 2 + VERT_SIZE;
+		midstar_pos0 += 16 + (c & 0x1F);
+		midstar_pos0 &= 0x3F;
+		midstar_pos0 += 2 + VERT_SIZE;
+#endif
+		midstar_color += 1 + (c & 0xC0 ? 0 : 1);
+	}
+
+	midstar_pos = midstar_pos0 - 2;
+}
+
+static unsigned char midstar_pixel(unsigned char pos)
+{
+	unsigned char dim;
+
+	if (pos != midstar_pos)
+		return 0;
+
+	if (pos > midstar_pos0) {
+		dim = pos - midstar_pos0;
+		if (dim < 2)
+			midstar_pos++;
+	} else {
+		dim = midstar_pos0 - pos;
+		midstar_pos++;
+	}
+
+	dim = midstar_bright >> 2*dim;
+	if (dim >= 2) {
+		switch (midstar_color & 0x7) {
+		case 0: send_rgb(dim, 0, 0); break;         // red
+		case 1: send_rgb(dim, dim, dim); break;     // white
+		case 2: send_rgb(0, dim, 0); break;         // green
+		case 3: send_rgb(dim, 0, dim); break;       // violet
+		case 4: send_rgb(dim, dim >> 2, 0); break;  // yellow/orange
+		case 5: send_rgb(0, dim, dim >> 2); break;  // cyan
+		case 6: send_rgb(0, 0, dim); break;         // blue
+		case 7: send_rgb(dim, dim, 0); break;       // yellow
+		}
+
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+static void background(unsigned char pos)
+{
+#ifdef CHRISTMAS_TREE
+	switch ((pos >> 4) & 3) {
+	case 0: if (pos & 1) send_rgb(7, 0, 0); else send_rgb(0, 7, 0);
+		break;
+	case 1: if (pos & 1) send_rgb(0, 0, 7); else send_rgb(7, 7, 7);
+		break;
+	case 2: if (pos & 1) send_rgb(7, 0, 7); else send_rgb(0, 7, 5);
+		break;
+	case 3: if (pos & 1) send_rgb(7, 5, 0); else send_rgb(7, 7, 7);
+		break;
+	}
+#else
+	send_rgb(0, 0, 7);
+#endif
+}
+
 int main(void)
 {
 	init_log();
+	init_rng();
+	init_serial();
 
-	log_set_state(3);
+	_delay_ms(3000/8); // wait for a bit and then increase the CPU clock
+	CLKPR = _BV(CLKPCE);
+	CLKPR = 0;
+
+	sei();
+
+#ifdef CHRISTMAS_TREE
+	down_star_init();
+#else
+	updown_star_init();
+#endif
+	midstar_init();
 
-	DDRB |= _BV(PB2);
 	while (1) {
-		PORTB |=  _BV( PB2 );
-		_delay_ms(200);
-		PORTB &=~ _BV( PB2 );
-		_delay_ms(200);
+		unsigned char i;
+
+		++jiffies;
+
+#ifdef CHRISTMAS_TREE
+		down_star_frame();
+#else
+		updown_star_frame();
+#endif
+		midstar_frame();
+		
+		for (i = 0; i < STRIP_SIZE; i++) {
+#ifdef CHRISTMAS_TREE
+			if (down_star_pixel(i)) continue;
+#else
+			if (updown_star_pixel(i)) continue;
+#endif
+			if (midstar_pixel(i)) continue;
+			background(i);
+		}
+		end_frame();
+		_delay_ms(30);
 	}
 }