From ba6556bec0920957b89ef4c69decb9b15d81a6f0 Mon Sep 17 00:00:00 2001
From: Thomas White <taw@physics.org>
Date: Sun, 9 Jul 2023 22:01:14 +0200
Subject: Handle multiple pixel strands

---
 pixelhub.cpp | 86 ++++++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 63 insertions(+), 23 deletions(-)

diff --git a/pixelhub.cpp b/pixelhub.cpp
index f876e08..506e1a1 100644
--- a/pixelhub.cpp
+++ b/pixelhub.cpp
@@ -25,63 +25,103 @@
 #include <ws2812.pio.h>
 
 const int dmx_rx_pin = 16;
-const int pixels_pin = 2;
-const int num_pixels = 8;
-const PIO led_pio = pio0;
-uint led_pio_sm;
+
+struct pixel_strip
+{
+	int pin;
+	int num_pixels;
+	PIO pio;
+	uint pio_sm;
+	uint offset;
+	uint32_t pixelbuf[256];
+	int rgbw;
+};
 
 
-static inline void put_pixel(uint32_t pixel_grb) {
-	pio_sm_put_blocking(led_pio, led_pio_sm, pixel_grb << 8u);
+static inline void put_pixel(struct pixel_strip *p, uint32_t pixel_grb) {
+	pio_sm_put_blocking(p->pio, p->pio_sm, pixel_grb);
 }
 
 
 static inline uint32_t urgb_u32(uint8_t r, uint8_t g, uint8_t b) {
-	return ((uint32_t) (r) << 8) | ((uint32_t) (g) << 16) | (uint32_t) (b);
+	return ((uint32_t)(g)<<24) | ((uint32_t)(r)<<16) | ((uint32_t)(b)<<8);
+}
+
+
+static inline uint32_t wrgb_u32(uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
+	return ((uint32_t)(g)<<24) | ((uint32_t)(r)<<16) | ((uint32_t)(b)<<8) | (uint32_t)(w);
+}
+
+
+static void init_pixel_strip(struct pixel_strip *p)
+{
+	int i;
+
+	p->pio_sm = pio_claim_unused_sm(p->pio, true);
+	p->offset = pio_add_program(p->pio, &ws2812_program);
+	ws2812_program_init(p->pio, p->pio_sm, p->offset, p->pin, 800000, p->rgbw);
+
+	for ( i=0; i<p->num_pixels; i++ ) {
+		p->pixelbuf[i] = 0;
+	}
+
 }
 
 
 int main()
 {
 	DmxInput dmx_in;
-	uint offset;
+	struct pixel_strip p1;
+	struct pixel_strip p2;
 	uint8_t dmxbuf[512];
-	uint32_t pixelbuf[num_pixels];
 	int i;
 	int blink = 1;
 
+	p1.pin = 2;
+	p1.num_pixels = 8;
+	p1.rgbw = false;
+	p1.pio = pio0;
+
+	p2.pin = 3;
+	p2.num_pixels = 1;
+	p2.rgbw = true;
+	p2.pio = pio0;
+
 	/* Initialise DMX */
 	dmx_in.begin(dmx_rx_pin, 1, 512);
 
 	/* Initialise Neopixels */
-	led_pio_sm = pio_claim_unused_sm(led_pio, true);
-    	offset = pio_add_program(led_pio, &ws2812_program);
-	ws2812_program_init(led_pio, led_pio_sm, offset, pixels_pin, 800000, false);
+	init_pixel_strip(&p1);
+	init_pixel_strip(&p2);
+	int npx = 8;
 
 	/* Status LED */
 	gpio_init(PICO_DEFAULT_LED_PIN);
 	gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
 
-	for ( i=0; i<num_pixels; i++ ) {
-		pixelbuf[i] = 0x00000000;  /* (W)GRB */
-	}
-
 	while (1) {
 
 		dmx_in.read(dmxbuf);
 
-		for ( i=0; i<num_pixels; i++) {
-			pixelbuf[i] = urgb_u32(dmxbuf[1+3*i+0],
-			                       dmxbuf[1+3*i+1],
-			                       dmxbuf[1+3*i+2]);
+		int dmxpos = 1;  /* Numbering starts at 1 */
+		for ( i=0; i<p1.num_pixels; i++) {
+			p1.pixelbuf[i] = urgb_u32(dmxbuf[dmxpos++],
+			                          dmxbuf[dmxpos++],
+			                          dmxbuf[dmxpos++]);
+		}
+		for ( i=0; i<p2.num_pixels; i++) {
+			p2.pixelbuf[i] = wrgb_u32(dmxbuf[dmxpos++],
+			                          dmxbuf[dmxpos++],
+			                          dmxbuf[dmxpos++],
+			                          dmxbuf[dmxpos++]);
 		}
 
-		for ( i=0; i<num_pixels; i++) {
-			put_pixel(pixelbuf[i]);
+		for ( i=0; i<npx; i++) {
+			put_pixel(&p1, p1.pixelbuf[i]);
+			put_pixel(&p2, p2.pixelbuf[i]);
 		}
 
 		gpio_put(PICO_DEFAULT_LED_PIN, blink);
 		blink = 1 - blink;
-		//sleep_us(100000);
 	}
 }
-- 
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