Replace MicroPython runtime with Pico C + W5500 firmware.

Ship UDP RGB panel firmware (eight WS2812 strips) and drop the ESP32 Wi-Fi/MicroPython stack.

Co-authored-by: Cursor <cursoragent@cursor.com>

firmware/WS2812.hpp

@@ -0,0 +1,46 @@
+#ifndef WS2812_H
+#define WS2812_H
+
+#include "hardware/pio.h"
+#include "pico/types.h"
+
+class WS2812 {
+ public:
+    enum DataByte { NONE = 0, RED = 1, GREEN = 2, BLUE = 3, WHITE = 4 };
+    enum DataFormat { FORMAT_RGB = 0, FORMAT_GRB = 1, FORMAT_WRGB = 2 };
+
+    WS2812(uint pin, uint length, PIO pio, uint sm);
+    WS2812(uint pin, uint length, PIO pio, uint sm, DataFormat format);
+    ~WS2812();
+
+    static uint32_t RGB(uint8_t red, uint8_t green, uint8_t blue) {
+        return (uint32_t)(blue) << 16 | (uint32_t)(green) << 8 | (uint32_t)(red);
+    }
+
+    void setPixelColor(uint index, uint32_t color);
+    void setPixelColor(uint index, uint8_t red, uint8_t green, uint8_t blue);
+    void fill(uint32_t color);
+    void show();
+    void show(uint count);
+    void setPin(uint pin);
+    uint getPin() const { return pin; }
+
+ private:
+    uint pin;
+    uint length;
+    PIO pio;
+    uint sm;
+    uint offset;
+    uint bits;
+    int dma_chan;
+    DataByte bytes[4];
+    uint32_t *data;
+
+    void initialize(uint pin, uint length, PIO pio, uint sm, DataByte b1, DataByte b2,
+                    DataByte b3, DataByte b4);
+    uint32_t convertData(uint32_t rgbw);
+    void applyPinConfig();
+    void dma_wait(void);
+};
+
+#endif