ESP32 memory management, Neopixels, and RGBPanels
summary
ESP32 reports 520KB spec, ~160KB usable for large global arrays, but memory is fragmented (DMA vs instruction cache regions) so big framebuffers blow out linking or crash at runtime; a 12 KB framebuffer fits on other MCUs but fails on a 1 KB task stack (1KB task stack), and converting large static arrays to malloced chunks saves about 39 KB in one case. Built a layer to run SmartMatrix / Adafruit FastLED / RGBPanel code on multiple backends, moved heavy work to a Raspberry Pi when 4096 Neopixels and RGB panels overwhelm the ESP32.
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chapters (7)
- 0:00Start
- 3:50Then I switched to RGBPanels, they need a lot more RAM
- 7:13Global Arrays can barely access 160KB
- 7:47Your program may compile, but crash at runtime
- 8:37Only 8KB of stack
- 10:56Converting arrays to mallocs
- 12:17Multi dimensional arrays with malloc and memory saved
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