How to flash it
- Install the ESPHome add-on (Settings → Add-ons) or ESPHome Device Builder in Docker.
- In ESPHome open Secrets and add your network’s wifi_ssid and wifi_password.
- New device → Continue → replace the generated config with the one above, Save → Install. The first time over USB (Plug into this computer, in Chrome or Edge); after that updates go over Wi-Fi.
- Home Assistant finds the device: Settings → Devices → Discovered → ESPHome; enter the encryption key from the config.
Free pins: ESP32 pinout, ESP8266. If the device is not found or you see “Error resolving IP address”, see the error explained. Check automation YAML: YAML checker.
What to buy
| What | Why | Where to look |
|---|---|---|
| ESP32 DevKit | The default choice: Wi-Fi, Bluetooth, many pins. | AliExpress |
| ESP32-C3 SuperMini | Tiny and cheap for a single sensor. | AliExpress |
| Wemos D1 mini | Older ESP8266, fine for simple sensors. | AliExpress |
| DHT22 | temperature and humidity | AliExpress |
| BME280 | temperature, humidity, pressure (I²C) | AliExpress |
| DS18B20 | temperature, waterproof probe | AliExpress |
| BH1750 | light level (I²C) | AliExpress |
| PIR motion sensor | AliExpress | |
| LD2410 | mmWave presence | AliExpress |
| Door reed switch | AliExpress | |
| Relay | AliExpress | |
| Button | AliExpress |
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