IMP: Improved the big LED strip demo

diff --git a/Examples/Big_LED_strip/Big_LED_strip.ino b/Examples/Big_LED_strip/Big_LED_strip.ino
index 0421bada468034f05d3e2a38221a74d4aa9e1ff7..d0b2c4219d3191ab8ecf35093490de5c11b6ed98 100644 (file)
--- a/Examples/Big_LED_strip/Big_LED_strip.ino
+++ b/Examples/Big_LED_strip/Big_LED_strip.ino
@@ -8,15 +8,7 @@
 #define BIG_IMAGE_FILE_SIZE    780
 #define DIMM                           4
 
-/*
-       ATMEGA328P has only 2KiB RAM. The three copies of the color data (const ppm image file,
-       working buffer and NeoPixel library buffer) alone require slightly more than that.
-       When loop() is called, the stack collides with the heap and overrides the library buffer.
-       The resulting visual effect is interesting but in order to actually display the image
-       we must do so directly without allocating a working buffer.
-       Ъomment this to indicate that display_rgb_direct() must be used.
-*/
-//#define NEOPIXEL_ATE_MY_RAM
+#define Y_U_NO_WORK
 //#define STM32
 
 #ifdef STM32
@@ -31,76 +23,40 @@ int display_rgb_direct(const uint8_t image[]);
 
 static const uint8_t big_image_data[BIG_IMAGE_FILE_SIZE] =
 {
-       0x50, 0x36, 0x0a, 0x33, 0x32, 0x20, 0x38, 0x0a, 0x32, 0x35, 0x35, 0x0a, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21,
-       0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3,
-       0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96,
-       0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00,
-       0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00,
-       0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21,
-       0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3,
-       0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21,
-       0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96,
-       0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00,
-       0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21,
-       0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00,
-       0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21,
-       0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96,
-       0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3,
-       0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21,
-       0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96,
-       0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+       0x50, 0x36, 0x0a, 0x33, 0x32, 0x20, 0x38, 0x0a, 0x32, 0x35, 0x35, 0x0a,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+       0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00,
+       0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00,
+       0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00,
+       0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00,
+       0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x21, 0x96, 0xf3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd5, 0x00, 0x00, 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
 Adafruit_NeoPixel led_matrix(NUM_PIXELS, LED_PIN, NEO_GRB);
 
 void setup()
 {
-       pinMode(LED_PIN, OUTPUT);
        led_matrix.begin();
+       led_matrix.fill(led_matrix.Color(0, 20 / DIMM, 6 / DIMM));
 }
 
 void loop()
 {
-       #ifdef NEOPIXEL_ATE_MY_RAM
+       #ifdef Y_U_NO_WORK
+
+       volatile uint8_t hax[27] = {0};         // Interesting values: 19, 20-31, 32, 50
        uint8_t frame_buffer[ROWS][COLS][3] = {{{0}}};
 
        render_image(frame_buffer, big_image_data);
        display_rgb(frame_buffer);
+
        #else
+
        display_rgb_direct(big_image_data);
-       #endif
 
+       #endif
 }
 
 int render_image(uint8_t buff[ROWS][COLS][3], const uint8_t image[])
@@ -135,20 +91,26 @@ int display_rgb(uint8_t buff[ROWS][COLS][3])
        {
                for (uint8_t row = 0; row < ROWS; row++)
                {
-                       led_matrix.setPixelColor(col * ROWS + row,
-                               led_matrix.Color(buff[row][col][0] / DIMM,
-                                                                buff[row][col][1] / DIMM,
-                                                                buff[row][col][2] / DIMM));
+                       if (buff[row][col][0] || buff[row][col][1] || buff[row][col][2])
+                       {
+                               led_matrix.setPixelColor(col * ROWS + row,
+                                       led_matrix.Color(buff[row][col][0] / DIMM,
+                                                                        buff[row][col][1] / DIMM,
+                                                                        buff[row][col][2] / DIMM));
+                       }
                }
        }
        for (uint8_t col = 1; col < COLS; col += 2)
        {
                for (uint8_t row = 0; row < ROWS; row++)
                {
-                       led_matrix.setPixelColor((col + 1) * ROWS - row - 1,
-                               led_matrix.Color(buff[row][col][0] / DIMM,
-                                                                buff[row][col][1] / DIMM,
-                                                                buff[row][col][2] / DIMM));
+                       if (buff[row][col][0] || buff[row][col][1] || buff[row][col][2])
+                       {
+                               led_matrix.setPixelColor((col + 1) * ROWS - row - 1,
+                                       led_matrix.Color(buff[row][col][0] / DIMM,
+                                                                        buff[row][col][1] / DIMM,
+                                                                        buff[row][col][2] / DIMM));
+                       }
                }
        }
        led_matrix.show();
@@ -158,7 +120,7 @@ int display_rgb(uint8_t buff[ROWS][COLS][3])
 
 int display_rgb_direct(const uint8_t image[])
 {
-       size_t row_offset, col_offset;
+       size_t row_offset, col_offset, offset;
 
        if (image == NULL)
                return -1;
@@ -169,10 +131,14 @@ int display_rgb_direct(const uint8_t image[])
                for (uint8_t row = 0; row < ROWS; row++)
                {
                        row_offset = row * COLS * 3;
-                       led_matrix.setPixelColor(col * ROWS + row,
-                               led_matrix.Color(image[PPM_HEADER_LENGHT + row_offset + col_offset] / DIMM,
-                                                                image[PPM_HEADER_LENGHT + row_offset + col_offset + 1] / DIMM,
-                                                                image[PPM_HEADER_LENGHT + row_offset + col_offset + 2] / DIMM));
+                       offset = PPM_HEADER_LENGHT + row_offset + col_offset;
+                       if (image[offset] || image[offset + 1] || image[offset + 2])
+                       {
+                               led_matrix.setPixelColor(col * ROWS + row,
+                                       led_matrix.Color(image[offset] / DIMM,
+                                                                        image[offset + 1] / DIMM,
+                                                                        image[offset + 2] / DIMM));
+                       }
                }
        }
        for (uint8_t col = 1; col < COLS; col += 2)
@@ -181,10 +147,14 @@ int display_rgb_direct(const uint8_t image[])
                for (uint8_t row = 0; row < ROWS; row++)
                {
                        row_offset = row * COLS * 3;
-                       led_matrix.setPixelColor((col + 1) * ROWS - row - 1,
-                               led_matrix.Color(image[PPM_HEADER_LENGHT + row_offset + col_offset] / DIMM,
-                                                                image[PPM_HEADER_LENGHT + row_offset + col_offset + 1] / DIMM,
-                                                                image[PPM_HEADER_LENGHT + row_offset + col_offset + 2] / DIMM));
+                       offset = PPM_HEADER_LENGHT + row_offset + col_offset;
+                       if (image[offset] || image[offset + 1] || image[offset + 2])
+                       {
+                               led_matrix.setPixelColor((col + 1) * ROWS - row - 1,
+                                       led_matrix.Color(image[offset] / DIMM,
+                                                                        image[offset + 1] / DIMM,
+                                                                        image[offset + 2] / DIMM));
+                       }
                }
        }
        led_matrix.show();