1. Setting Up the Development Environment

I recommend using PlatformIO (VS Code extension) instead of Arduino IDE. PlatformIO has native support for the XIAO ESP32S3 Sense, so you don’t need to fall back on “ESP32S3 Dev Module.”

• Install VS Code
• Install PlatformIO IDE extension
• Create a new project, and select:
  • Board: Seeed Studio XIAO ESP32S3
  • Framework: Arduino

Your platformio.ini should look like this:

[env:seeed_xiao_esp32s3]
platform = espressif32
board = seeed_xiao_esp32s3
framework = arduino
monitor_speed = 115200

2. LED Blink Test

Always start simple. Run a blink sketch to confirm that the board and toolchain are working.

#include <Arduino.h>
#define LED_BUILTIN 21   // Yellow onboard LED

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
}

If the yellow LED blinks, your setup is good to go.

3. Camera Initialization & Web Streaming

The XIAO ESP32S3 Sense comes with an OV2640 camera module. Below is a simplified snippet of the setup code (PlatformIO + Arduino framework):

#include "esp_camera.h"
#include <WiFi.h>
#include <WebServer.h>

#define XCLK_GPIO_NUM  10
#define SIOD_GPIO_NUM  40
#define SIOC_GPIO_NUM  39
#define Y9_GPIO_NUM    48
#define Y8_GPIO_NUM    11
#define Y7_GPIO_NUM    12
#define Y6_GPIO_NUM    14
#define Y5_GPIO_NUM    16
#define Y4_GPIO_NUM    18
#define Y3_GPIO_NUM    17
#define Y2_GPIO_NUM    15
#define VSYNC_GPIO_NUM 38
#define HREF_GPIO_NUM  47
#define PCLK_GPIO_NUM  13

const char *ssid = "YourWiFi";
const char *password = "Password";

WebServer server(80);

void startCameraServer() {
  server.on("/", HTTP_GET, []() {
    server.send(200, "text/html", "<h1>ESP32S3 Camera</h1><img src=\"/stream\">");
  });
  server.begin();
}

When successful, you’ll see an IP address in the Serial Monitor (e.g. 192.168.1.104).
Open http://192.168.1.104/stream in a browser to view the camera feed.

4. WiFi Connection & Debugging

A very common beginner issue is WiFi not connecting. Here are some tips:

• ESP32 supports only 2.4GHz WiFi (no 5GHz support).
• Keep your SSID and password simple (no unusual characters).
• Use a WiFi scan to confirm available networks:

Serial.println("Scanning WiFi...");
int n = WiFi.scanNetworks();
for (int i = 0; i < n; i++) {
  Serial.printf("%d: %s (%d dBm)\n", i+1, WiFi.SSID(i).c_str(), WiFi.RSSI(i));
}

• Print connection status codes while connecting:
  • 1 = WL_NO_SSID_AVAIL → AP not found
  • 3 = WL_CONNECTED → Connected successfully
  • 4 = WL_CONNECT_FAILED → Wrong password

5. Power Supply Pitfalls (The Biggest Trap!)

Here’s the #1 issue I ran into:

• When powered via PC USB → everything worked, video stream was fine.
• When powered via a cheap USB adapter or power bank → black screen, page not loading, or extreme lag.

Why? The ESP32S3 + Camera can draw 500–700mA at peak. Many USB adapters and thin cables can’t supply this reliably.

Fixes

• Use a stable 5V / 2A USB power adapter
• Use a short, thick USB cable (30–50 cm, rated for 2A current)
• If you must use a weak power source, lower the camera load:

config.frame_size   = FRAMESIZE_QQVGA;   // 160x120
config.jpeg_quality = 20;                // High compression
config.xclk_freq_hz = 10000000;          // Lower clock speed
config.fb_count     = 1;                 // Single framebuffer

6. Common Issues & Solutions

• Black screen → Power supply too weak / camera init failed
• Page loads but extremely slow → WiFi unstable or CPU overloaded with JPEG compression
• WiFi won’t connect → Check 2.4GHz availability, WPA2-PSK(AES) recommended
• High latency → Either power issue or resolution too high

7. Suggested Beginner Workflow

1. Verify development environment with LED Blink
2. Test WiFi connectivity with a network scan
3. Connect to WiFi and run basic camera streaming
4. Solve power supply issues for stability
5. Fine-tune resolution, frame rate, and JPEG quality for your use case

8. Changing PlatformIO Default Project Directory

By default, PlatformIO creates all new projects under:

~/Documents/PlatformIO/Projects/

On Linux, this path expands to something like:

/home/username/Documents/PlatformIO/Projects/

If you prefer to keep your projects in another location (for example, under ~/dev/platformio_projects), you can change this setting inside VS Code.

Steps:

1. Open VS Code.
2. Press Ctrl+Shift+P → type Preferences: Open User Settings (JSON).
3. In the settings.json, add the following line: "platformio-ide.projectsDir": "/home/yourname/dev/platformio_projects"
4. Save and restart VS Code.

From now on, all new PlatformIO projects will be created under your custom directory.