ESP32 projects for beginners: 10 builds that teach you something

You learn embedded electronics by finishing things, not by reading datasheets. Each project here is small enough to complete in an evening and teaches exactly one new idea: a radio, a sensor, a display, low-power sleep or over-the-air updates. Do them in order and by the end you can build most hobby gadgets from scratch.

01What you need before you start

Very little. An ESP32 board, a USB-C cable and the free Arduino IDE with the Arduino-ESP32 core installed (board manager URL from Espressif). The examples here use core version 3.x, the current generation. A few projects add a cheap sensor or display; the rest run on a bare board.

• Board: any ESP32 or ESP32-S3 development board. A board with an onboard LED and native USB saves you wiring.
• Optional parts: a DHT22 temperature sensor, a small I2C OLED (SSD1306), a micro servo (SG90) and an electret or I2S microphone. None cost much.
• No soldering for most of the list. A breadboard and jumper wires help for the sensor builds.

02The 10 projects at a glance

Here is the whole path. Difficulty is relative to the one before it, not an absolute scale.

03Projects 1–2: lights and a web page

1. Blink or RGB fade. The classic first step. Toggle the onboard LED once a second, then fade an RGB LED through colors. You learn the build-and-flash cycle, how a GPIO pin drives a load, and how delay() and millis() handle timing. On an ESP32-S3 with an addressable LED, the Adafruit_NeoPixel library drives it in a few lines. Parts: board only.

2. Wi-Fi web server to control an LED. This is the project that makes the ESP32 click for most people. The board joins your Wi-Fi, serves a tiny web page, and a link on that page turns the LED on and off. Now your gadget has a user interface that any phone on the network can open, with no app to install. Parts: board only.

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

const char* SSID = "your-wifi";
const char* PASS = "your-password";
const int   LED  = 2;            // change to your board's LED pin

WebServer server(80);

void sendPage() {
  bool on = digitalRead(LED);
  String html = "<h1>ESP32 LED</h1><p>LED is ";
  html += on ? "ON" : "OFF";
  html += "</p><a href='/toggle'>Toggle</a>";
  server.send(200, "text/html", html);
}

void setup() {
  Serial.begin(115200);
  pinMode(LED, OUTPUT);
  WiFi.begin(SSID, PASS);
  while (WiFi.status() != WL_CONNECTED) delay(300);
  Serial.println(WiFi.localIP());   // open this address in a browser

  server.on("/", sendPage);
  server.on("/toggle", []() {
    digitalWrite(LED, !digitalRead(LED));
    server.sendHeader("Location", "/");
    server.send(303);            // redirect back to the page
  });
  server.begin();
}

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

Flash it, open the Serial Monitor at 115200 baud, note the IP address it prints, and type that address into a browser on the same network. Every time you learn a new sensor later, you can show its value on a page like this one.

04Projects 3, 4 & 8: read the world

3. DHT22 temperature and humidity dashboard. Wire a DHT22 to one GPIO and 3.3 V, read it with the DHT library, and show temperature and humidity on a web page that refreshes itself every few seconds. You learn how a one-wire digital sensor works and how to turn live data into a simple dashboard. Parts: DHT22, one pull-up resistor. Difficulty: easy.

4. BLE beacon scanner. Switch from Wi-Fi to the other radio. The ESP32 listens for Bluetooth Low Energy advertisements from nearby phones, fitness bands and beacons, and prints each device's address and signal strength (RSSI). You learn how BLE advertising works and how RSSI drops with distance — the same idea behind phone "nearby device" features. Keep it defensive: scan only your own devices, and never try to connect to or interfere with hardware that is not yours. Parts: board only. Difficulty: medium.

8. Sound-level meter. Feed a microphone into the ESP32, either an analog electret module on an ADC pin or a digital I2S mic, sample it fast, and compute a rolling loudness level that you show as a bar. You learn basic sampling and that a "sound level" is a short-term average, not a single reading. It is a gentle on-ramp to real signal processing. Parts: electret or I2S microphone. Difficulty: medium.

05Projects 6 & 7: a display and some motion

6. OLED clock synced over NTP. Connect a small SSD1306 OLED over I2C (two wires plus power), join Wi-Fi, ask a public NTP server for the time, set the ESP32's clock and draw the time on the screen. You learn I2C, network time and why time zones and daylight saving need a little care. The result is a genuinely useful desk clock that never drifts. Parts: SSD1306 OLED. Difficulty: medium.

7. Web-controlled servo. Combine the web server from project 2 with a hobby servo. A slider on the page sets the angle; the ESP32 generates the PWM signal that moves the horn. You learn pulse-width modulation and the habit of powering a motor from its own supply rather than the board's 3.3 V rail. Parts: SG90 servo, separate 5 V supply. Difficulty: medium.

06Projects 5, 9 & 10: deploy like a product

The last three turn a desk experiment into something you can actually install and leave running.

5. Deep-sleep battery sensor. A sensor that reports once a minute does not need to stay awake. Read the value, send it, then call esp_deep_sleep with a wake timer. The board wakes, works for a second and sleeps again. A bare ESP32 module drops to tens of microamps asleep, so the battery lasts far longer. You learn the single most important idea in battery electronics: do the work, then sleep. Parts: any sensor, a battery. Difficulty: medium.

9. Captive-portal config page. Hard-coding your Wi-Fi password into every sketch is painful. Instead, make the ESP32 start its own access point and a small web page where you type the network name and password, which it saves to flash. A DNS redirect pops that page up automatically when you join, the way hotel and airport Wi-Fi logins appear. You learn access-point mode, non-volatile storage and a realistic setup flow. Parts: board only. Difficulty: harder.

10. OTA firmware update. Walking a USB cable to a board hidden behind a wall gets old fast. With the ArduinoOTA library the ESP32 accepts new firmware over Wi-Fi, so it shows up as a network target in the IDE. You learn how over-the-air updates work and why version numbers and a safe fallback matter once a device is out of reach. Parts: board only. Difficulty: harder.

07Which board should you buy?

Any ESP32 or ESP32-S3 dev board runs all ten projects. For a first board, two things genuinely help: native USB (so you do not fight driver issues) and an onboard LED and button (so projects 1, 2 and 9 need no wiring at all). ESP32-S3 boards add more memory and USB features, which make the OTA and captive-portal builds smoother.

If you would rather not breadboard anything, a finished pocket board gets you to the Wi-Fi, BLE, deep-sleep, captive-portal and OTA projects with zero wiring.

08FAQ

SGP Lab — written by the team that designs and builds SGP hardware in Europe. We test every example on our own boards before publishing.