Rust
19 Sep 2026
8 min read
Streaming Sensor Graphs to ILI9341 Without a Framebuffer on ESP32-C3
An ILI9341 panel is large enough for a useful live sensor graph, but a 240 × 320 RGB565 framebuffer costs 153,600 bytes: 240 * 320 * 2 bytes = 153,600 bytes That is a poor default allocation on a small microcontroller when the graph itself may need only a few hundred samples. The display controller already contains its own graphics RAM. An ESP32-C3 can therefore treat the panel as the destination, keep only the application state it needs, and send changed pixels over SPI.