new structure

src/main.c

@@ -43,21 +43,14 @@ int main()
 	sleep_ms(100);
 	tft_start_pixels(lcd_config.pio, lcd_config.sm);
 	while (true){
-		for(size_t i = 0; i < 8; i++) {
+		tft_start_pixels(lcd_config.pio, lcd_config.sm);
 		tft_fill(0);
 		dma_channel_wait_for_finish_blocking(dma_chan);
-		}
+		sleep_ms(1000);
 		tft_start_pixels(lcd_config.pio, lcd_config.sm);
-		absolute_time_t start = get_absolute_time();
-		for(size_t i = 0; i < 8; i++) {
 		tft_fill(31807);
 		dma_channel_wait_for_finish_blocking(dma_chan);
-		}
-		absolute_time_t end = get_absolute_time();
-		volatile int64_t diff = absolute_time_diff_us(start, end);
-		tft_fill(31807);
-		dma_channel_wait_for_finish_blocking(dma_chan);
-		// actual refresh rate ~25hz
+		sleep_ms(1000);
 	}
 	return 0;
 }

src/tft/tft.c

@@ -60,6 +60,8 @@ void tft_init(const struct tft_config* config, int dma_channel) {
     gpio_put(tft_cfg.gpio_bl, 1);
 }
 void tft_fill(uint16_t color) {
+    for(size_t i = 0; i < 8; i++) {
+		dma_channel_wait_for_finish_blocking(dma_chan);
         uint32_t color_left = ((uint32_t)color) << 16;
         uint32_t two = 0;
         two |= color_left;
@@ -69,4 +71,6 @@ void tft_fill(uint16_t color) {
 	    	pix_buf[i] = two;
 	    }
         dma_channel_set_read_addr(dma_chan, pix_buf, true);
+	}
+
 }