Aijia Yao

PCB Design

Since all my previous PCB used XIAO-RP2040 as the microcontroller, to achieve wireless communication, I just modify the PCB based on the design in Week 8, it was almost the same except switching from RP2040 to XIAO_ESP32S3.

Testing and Integration

• Assembled the PCB and first connected with cable to test with Arduino IDE.
• For wireless connection, I put the led to test by sending control to change the color through wifi.

Below is a demo video of the wireless control of the led color:

The code for this wireless test is as followed.

#include <WiFi.h>>
#include <WebServer.h>>
#include <Adafruit_NeoPixel.h>

// ==== NeoPixel config ====
#define LED_PIN     6       // DIN connected to GPIO6
#define NUM_PIXELS  1       // number of LEDs
#define BRIGHTNESS  80      // 0–255

Adafruit_NeoPixel pixels(NUM_PIXELS, LED_PIN, NEO_GRB + NEO_KHZ800);

// ==== WiFi AP config ====
const char* ap_ssid     = "SSID";
const char* ap_password = "PASSWORD"; 

WebServer server(80);

// ---- Helper: set LED color ----
void setColor(uint8_t r, uint8_t g, uint8_t b) {
  pixels.setPixelColor(0, pixels.Color(r, g, b));
  pixels.show();
}

// ---- HTTP handlers ----
void handleRoot() {
  String html = R"(



  
  
  


  
ESP32 NeoPixel Control
  
Click a color:
  

    Red
    Green
    Blue
    White
    Off
  
  
You can also call /set?r=R&g=G&b=B manually.


  )";

  server.send(200, "text/html", html);
}

void handleSet() {
  // get r, g, b from URL query, default 0
  int r = server.hasArg("r") ? server.arg("r").toInt() : 0;
  int g = server.hasArg("g") ? server.arg("g").toInt() : 0;
  int b = server.hasArg("b") ? server.arg("b").toInt() : 0;

  // clamp 0–255
  if (r < 0) r = 0; if (r > 255) r = 255;
  if (g < 0) g = 0; if (g > 255) g = 255;
  if (b < 0) b = 0; if (b > 255) b = 255;

  setColor((uint8_t)r, (uint8_t)g, (uint8_t)b);

  String resp = "Set color to R=" + String(r) +
                " G=" + String(g) +
                " B=" + String(b) + "\n";
  resp += "Back to control page";
  server.send(200, "text/html", resp);
}

void handleNotFound() {
  server.send(404, "text/plain", "Not found");
}

void setup() {
  Serial.begin(115200);
  delay(1000);

  // NeoPixel init
  pixels.begin();
  pixels.setBrightness(BRIGHTNESS);
  setColor(0, 0, 0);   // start off

  // WiFi AP mode
  WiFi.mode(WIFI_AP);
  bool ap_ok = WiFi.softAP(ap_ssid, ap_password);
  if (ap_ok) {
    Serial.println("AP started");
    Serial.print("SSID: ");
    Serial.println(ap_ssid);
    Serial.print("Password: ");
    Serial.println(ap_password);
    Serial.print("IP: ");
    Serial.println(WiFi.softAPIP()); // usually 192.168.4.1
  } else {
    Serial.println("AP start FAILED");
  }

  // HTTP routes
  server.on("/", handleRoot);
  server.on("/set", handleSet);
  server.onNotFound(handleNotFound);

  server.begin();
  Serial.println("HTTP server started");
}

void loop() {
  server.handleClient();
}