Getting Started with ESP32

Easy 20 min $5-10

ESP32 is a microcontroller - a small computer that can measure things, control things, and talk to your WiFi. Together with ESPHome, it becomes easy to build your own smart home devices.

📋 Prerequisites

Before you start, you need:

• ✅ Home Assistant running
• ✅ A computer with USB port
• ✅ Chrome or Edge browser (for USB flash)

🤔 What is ESPHome?

ESPHome is software that runs on your ESP32. You describe what it should do in a simple YAML file, and ESPHome handles the rest.

Benefits:

• No Arduino IDE or C++ programming
• Direct integration with Home Assistant
• Wireless updates (OTA)

🛒 Choose Your Board

Board	Price	Recommended for
ESP32-WROOM-32 DevKit	$5-10	⭐ Beginners (start here)
ESP32-C3 Super Mini	$3-5	Small projects
ESP32-S3	$8-12	Displays, more RAM

Tip

Start with a WROOM-32 DevKit. It’s wide enough to see what you’re doing, and all our guides use it.

⚙️ Install ESPHome Add-on

1. Open Home Assistant and go to Settings → Add-ons

2. Click Add-on Store (bottom right)

3. Search for “ESPHome” and click on it

4. Click Install and wait (1-2 minutes)

5. Enable “Start on boot” and “Show in sidebar”

6. Click Start

Note

The ESPHome icon now appears in your sidebar on the left.

🔌 Create Your First Device

1. Open ESPHome from the sidebar

2. Click + NEW DEVICE

3. Click Continue (ignore browser-flash for now)

4. Name the device - e.g., test-sensor

   Caution

   Use only lowercase letters, numbers, and hyphens. No spaces or special characters.

5. Select ESP32 as device type

6. Click Skip (we’ll flash manually afterwards)

📝 Configure the Device

Click EDIT on your new device and replace the content with:

test-sensor.yaml

esphome:
  name: test-sensor
  friendly_name: Test Sensor

esp32:
  board: esp32dev

# Logging for debugging
logger:

# Home Assistant API
api:
  encryption:
    key: "YOUR-AUTO-GENERATED-KEY"

# Wireless updates
ota:
  platform: esphome

# WiFi connection
wifi:
  ssid: "YOUR-WIFI-NAME"
  password: "YOUR-WIFI-PASSWORD"

# Fallback hotspot if WiFi fails
captive_portal:

# Simple test sensor - WiFi signal strength
sensor:
  - platform: wifi_signal
    name: "WiFi Signal"
    update_interval: 60s

Tip

Replace YOUR-WIFI-NAME and YOUR-WIFI-PASSWORD with your actual WiFi credentials.

📤 Flash to ESP32

🌐 Web (easiest)

1. Connect ESP32 to computer with USB cable

2. Click INSTALL → Plug into this computer

3. Select “Serial” in the popup window

4. Select the correct COM port (typically the only one shown)

5. Wait for upload (~2 minutes)

6. You’ll see “INFO Successfully uploaded” when done

Caution

Only works in Chrome or Edge. Firefox doesn’t support Web Serial.

💻 ESPHome CLI

If web-flash doesn’t work:

# Install ESPHome CLI
pip install esphome

# Flash via USB
esphome run test-sensor.yaml

✅ Add to Home Assistant

1. Go to Settings → Devices & Services

2. Home Assistant automatically finds your ESP32 under “Discovered”

3. Click Configure

4. Enter your encryption key (from the YAML file)

5. Click Submit → Finish

Your ESP32 is now connected! 🎉

🧪 Test It Works

1. Go to Developer Tools → States

2. Search for sensor.test_sensor_wifi_signal

3. You should see a value like -45 dBm

WiFi signal strength

• -30 to -50 dBm: Excellent
• -50 to -70 dBm: Good
• -70 to -80 dBm: Weak
• Below -80 dBm: Unstable

🔧 Troubleshooting

ESP32 not found?

• Try a different USB cable (some are charge-only)
• Try a different USB port
• Install CH340 driver: Windows / Mac

WiFi won't connect?

• Double-check SSID and password (case-sensitive)
• ESP32 only supports 2.4 GHz WiFi, not 5 GHz
• Try being closer to the router

Home Assistant doesn't find the device?

• Check that ESP32 and HA are on the same network
• Restart the ESPHome add-on
• Check ESPHome logs for errors

🚀 Next Steps

🌡️ Temperature Sensor

Add a DHT22 and measure temperature/humidity.

Build temperature sensor →

🚶 Motion Sensor

Add a PIR sensor for motion detection.

Build motion sensor →