Make ws2812 and apa102 responsibly only for their own buffers

This fixes a bug where delete[] would be called on a bytearray buffer allocated by MicroPython on gc_heap.

drivers/plasma/apa102.cpp

@@ -34,6 +34,7 @@ APA102::APA102(uint num_leds, PIO pio, uint sm, uint pin_dat, uint pin_clk, uint
 
     if(this->buffer == nullptr) {
         this->buffer = new RGB[num_leds];
+        managed_buffer = true;
     }
 }
 

drivers/plasma/apa102.hpp

@@ -66,7 +66,10 @@ namespace plasma {
                 // pio_sm_unclaim seems to hardfault in MicroPython
                 pio_sm_unclaim(pio, sm);
 #endif
-                delete[] buffer;
+                if(managed_buffer) {
+                    // Only delete buffers we have allocated ourselves.
+                    delete[] buffer;
+                }
             }
             bool start(uint fps=60);
             bool stop();
@@ -86,5 +89,6 @@ namespace plasma {
             uint pio_program_offset;
             int dma_channel;
             struct repeating_timer timer;
+            bool managed_buffer = false;
     };
 }

drivers/plasma/ws2812.cpp

@@ -33,6 +33,7 @@ WS2812::WS2812(uint num_leds, PIO pio, uint sm, uint pin, uint freq, bool rgbw,
 
     if(!this->buffer) {
         this->buffer = new RGB[num_leds];
+        managed_buffer = true;
     }
 }
 

drivers/plasma/ws2812.hpp

@@ -75,7 +75,10 @@ namespace plasma {
                 // pio_sm_unclaim seems to hardfault in MicroPython
                 pio_sm_unclaim(pio, sm);
 #endif
-                delete[] buffer;
+                if(managed_buffer) {
+                    // Only delete buffers we have allocated ourselves.
+                    delete[] buffer;
+                }
             }
             bool start(uint fps=60);
             bool stop();
@@ -95,5 +98,6 @@ namespace plasma {
             uint pio_program_offset;
             int dma_channel;
             struct repeating_timer timer;
+            bool managed_buffer = false;
     };
 }