first upload

Master/Master.ino

@@ -0,0 +1,55 @@
+#include <Wire.h>
+
+#define I2C_DEV_ADDR 0x55  // Must match slave
+
+void setup() {
+  Serial.begin(115200);
+  Wire.begin(); // default pins for ESP32-C3: SDA=8, SCL=9
+  Serial.println("Enter number of pixels:");
+}
+
+void loop() {
+  static int numPixels = 0;
+  static bool pixelsSet = false;
+
+  // Step 1: Get number of pixels from user
+  if (!pixelsSet && Serial.available()) {
+    numPixels = Serial.parseInt();
+    if (numPixels > 0 && numPixels <= 100) { // reasonable limit
+      Wire.beginTransmission(I2C_DEV_ADDR);
+      Wire.write(0x01); // Command: set pixel count
+      Wire.write(numPixels);
+      Wire.endTransmission();
+      pixelsSet = true;
+      Serial.println("Enter command: (example: ALL 255 0 0 128) or (PIXEL 3 0 255 0 255)");
+      Serial.println("Format:");
+      Serial.println("ALL R G B I");
+      Serial.println("PIXEL N R G B I");
+    } else {
+      Serial.println("Invalid pixel count. Try again.");
+    }
+  }
+
+  // Step 2: Get lighting commands from user
+  if (pixelsSet && Serial.available()) {
+    String cmd = Serial.readStringUntil('\n');
+    cmd.trim();
+
+    if (cmd.startsWith("ALL")) {
+      int r, g, b, i;
+      sscanf(cmd.c_str(), "ALL %d %d %d %d", &r, &g, &b, &i);
+      Wire.beginTransmission(I2C_DEV_ADDR);
+      Wire.write(0x02); // Command: set all pixels
+      Wire.write(r); Wire.write(g); Wire.write(b); Wire.write(i);
+      Wire.endTransmission();
+    } else if (cmd.startsWith("PIXEL")) {
+      int n, r, g, b, i;
+      sscanf(cmd.c_str(), "PIXEL %d %d %d %d %d", &n, &r, &g, &b, &i);
+      Wire.beginTransmission(I2C_DEV_ADDR);
+      Wire.write(0x03); // Command: set one pixel
+      Wire.write(n); Wire.write(r); Wire.write(g); Wire.write(b); Wire.write(i);
+      Wire.endTransmission();
+    }
+    Serial.println("Command sent.");
+  }
+}

Slave/Slave.ino

@@ -0,0 +1,56 @@
+#include <Wire.h>
+#include <Adafruit_NeoPixel.h>
+
+#define I2C_DEV_ADDR 0x55
+#define NEOPIXEL_PIN 19 // Change as needed
+#define MAX_PIXELS 100
+
+Adafruit_NeoPixel strip(MAX_PIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);
+
+uint8_t pixelCount = 1;
+
+void receiveEvent(int len) {
+  delay(50); // Add more delay for stability as requested
+
+  if (len < 1) return;
+  uint8_t cmd = Wire.read();
+
+  if (cmd == 0x01 && len >= 2) { // Set pixel count
+    pixelCount = Wire.read();
+    strip.updateLength(pixelCount);
+    strip.begin();
+    strip.show();
+  }
+  else if (cmd == 0x02 && len >= 5) { // Set all pixels: R G B I
+    uint8_t r = Wire.read();
+    uint8_t g = Wire.read();
+    uint8_t b = Wire.read();
+    uint8_t intensity = Wire.read();
+    for (int i = 0; i < pixelCount; i++) {
+      strip.setPixelColor(i, strip.Color(r * intensity / 255, g * intensity / 255, b * intensity / 255));
+    }
+    strip.show();
+  }
+  else if (cmd == 0x03 && len >= 6) { // Set one pixel: N R G B I
+    uint8_t n = Wire.read();
+    uint8_t r = Wire.read();
+    uint8_t g = Wire.read();
+    uint8_t b = Wire.read();
+    uint8_t intensity = Wire.read();
+    if (n < pixelCount) {
+      strip.setPixelColor(n, strip.Color(r * intensity / 255, g * intensity / 255, b * intensity / 255));
+      strip.show();
+    }
+  }
+}
+
+void setup() {
+  strip.begin();
+  strip.show();
+  Wire.begin(I2C_DEV_ADDR, 8, 9); // ESP32-S3 default I2C pins: SDA=8, SCL=9
+  Wire.onReceive(receiveEvent);
+}
+
+void loop() {
+  delay(100); // Main loop delay, not critical
+}