Working with DMA

1 files changed, 33 insertions, 35 deletions

diff --git a/pixelhub.cpp b/pixelhub.cpp
index 660ecc7..6a1e36b 100644
--- a/pixelhub.cpp
+++ b/pixelhub.cpp
@@ -59,14 +59,14 @@ static inline uint32_t wrgb_u32(uint8_t r, uint8_t g, uint8_t b, uint8_t w)
 
 uint dma_chan;
 dma_channel_config dma_conf;
-struct pixel_strip strips[8];
-int n_strips;
+struct pixel_strip pxs[8];
+int n_pxs;
 int cur_strip = 0;
 
 
 static void set_dma()
 {
-	struct pixel_strip *p = &strips[cur_strip];
+	struct pixel_strip *p = &pxs[cur_strip];
 	channel_config_set_dreq(&dma_conf,
 	                        pio_get_dreq(p->pio, p->pio_sm, true));
 	dma_channel_configure(p->dma_chan, &dma_conf,
@@ -80,7 +80,7 @@ static void set_dma()
 static int64_t next_strip(alarm_id_t id, void *vp)
 {
 	cur_strip++;
-	if ( cur_strip >= n_strips ) cur_strip = 0;
+	if ( cur_strip >= n_pxs ) cur_strip = 0;
 	set_dma();
 	return 0;
 }
@@ -95,17 +95,23 @@ static void dma_complete()
 }
 
 
-static void init_pixel_strip(struct pixel_strip *p)
+static void init_pixel_strip(struct pixel_strip *p, PIO pio, int sm)
 {
 	int i;
 
-	p->pio_sm = pio_claim_unused_sm(p->pio, true);
+	p->pio = pio;
+	p->pio_sm = sm;
 	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] = 127;
+		p->pixelbuf[i] = urgb_u32(32, 0, 32);
 	}
+
+	pio_sm_set_enabled(pio, sm, false);
+	pio_sm_clear_fifos(pio, sm);
+	pio_sm_restart(pio, sm);
+	pio_sm_set_enabled(pio, sm, true);
 }
 
 
@@ -116,43 +122,34 @@ int main()
 	int i;
 	int blink = 1;
 
-	strips[0].pin = 2;
-	strips[0].num_pixels = 8;
-	strips[0].rgbw = false;
-	strips[0].pio = pio0;
+	pxs[0].pin = 2;
+	pxs[0].num_pixels = 8;
+	pxs[0].rgbw = false;
 
-	strips[1].pin = 3;
-	strips[1].num_pixels = 1;
-	strips[1].rgbw = true;
-	strips[1].pio = pio0;
+	pxs[1].pin = 3;
+	pxs[1].num_pixels = 1;
+	pxs[1].rgbw = true;
 
-	n_strips = 1;
+	n_pxs = 1;
 
 	/* Initialise DMX */
 	dmx_in.begin(dmx_rx_pin, 1, 512);
 
 	/* Initialise Neopixels */
-	init_pixel_strip(&strips[0]);
-	init_pixel_strip(&strips[1]);
+	init_pixel_strip(&pxs[0], pio0, 0);
+	//init_pixel_strip(&pxs[1]);
 
 	/* Start DMA */
 	dma_chan = dma_claim_unused_channel(true);
 	dma_conf = dma_channel_get_default_config(dma_chan);
 	channel_config_set_read_increment(&dma_conf, true);
 	channel_config_set_write_increment(&dma_conf, false);
-	//irq_set_exclusive_handler(DMA_IRQ_0, dma_complete);
-	//dma_channel_set_irq0_enabled(dma_chan, true);
-	//irq_set_enabled(DMA_IRQ_0, true);
-	cur_strip = 0;
-	//set_dma();
-
-	struct pixel_strip *p = &strips[0];
 	channel_config_set_dreq(&dma_conf,
-	                        pio_get_dreq(p->pio, p->pio_sm, true));
-	dma_channel_configure(p->dma_chan, &dma_conf,
-	                      &p->pio->txf[p->pio_sm],  /* Dest */
-	                      p->pixelbuf,             /* Source */
-	                      p->num_pixels,
+	                        pio_get_dreq(pxs[0].pio, pxs[0].pio_sm, true));
+	dma_channel_configure(dma_chan, &dma_conf,
+	                      &pxs[0].pio->txf[pxs[0].pio_sm],  /* Dest */
+	                      pxs[0].pixelbuf,             /* Source */
+	                      pxs[0].num_pixels,
 	                      true);
 
 	/* Status LED */
@@ -165,16 +162,17 @@ int main()
 		//dmx_in.read(dmxbuf);
 
 		//int dmxpos = 1;  /* Numbering starts at 1 */
-		//for ( i=0; i<strips[0].num_pixels; i++) {
-		//	strips[0].pixelbuf[i] = urgb_u32(0, 0, 32);
+		//for ( i=0; i<pxs[0].num_pixels; i++) {
+		//	put_pixel(&pxs[0], urgb_u32(32, 0, 0));
 		//}
-		//for ( i=0; i<strips[1].num_pixels; i++) {
-		//	strips[1].pixelbuf[i] = wrgb_u32(0, 64, 0, 0);
+		//sleep_ms(10);
+		//for ( i=0; i<pxs[1].num_pixels; i++) {
+		//	pxs[1].pixelbuf[i] = wrgb_u32(0, 64, 0, 0);
 		//}
 
 		gpio_put(PICO_DEFAULT_LED_PIN, blink);
 		loop++;
-		if ( loop > 1000000 ) {
+		if ( loop > 3000000 ) {
 			loop = 0;
 			blink = 1 - blink;
 		}