ESPHome on Wemos D1 Mini

This guide covers the installation and configuration of ESPHome for the Wemos D1 Mini, a popular and affordable ESP8266-based development board.

Prerequisites

• Hardware: Wemos D1 Mini (or clone), Micro-USB cable (ensure it supports data, not just charging).
• Software: Python installed (for CLI) or a browser with Web Serial support (Chrome/Edge) for the web dashboard.

Installation

Option 1: Web Dashboard (Recommended for Beginners)

1. Connect your Wemos D1 Mini to your computer via USB.
2. Go to web.esphome.io.
3. Click Connect and select the COM port associated with your device.
4. Follow the on-screen instructions to prepare your device for the first time.

Option 2: Command Line Interface (CLI)

If you prefer the terminal, you can install ESPHome via pip:

pip install esphome

Basic Configuration

Create a new YAML file (e.g., living-room.yaml) with the following basic configuration for a Wemos D1 Mini.

esphome:
  name: living-room-sensor
  friendly_name: Living Room Sensor

esp8266:
  board: d1_mini

# Enable logging
logger:

# Enable Home Assistant API
api:

# Enable Over-The-Air updates
ota:
  - platform: esphome

wifi:
  ssid: "YourWiFiName"
  password: "YourWiFiPassword"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Living-Room-Sensor Fallback Hotspot"
    password: "fallback_password"

captive_portal:

Pinout Reference

The Wemos D1 Mini pins map to ESP8266 GPIOs as follows:

Label	GPIO	Function
D0	GPIO16	Wake
D1	GPIO5	I2C SCL
D2	GPIO4	I2C SDA
D3	GPIO0	Flash
D4	GPIO2	TX1 / LED
D5	GPIO14	SPI CLK
D6	GPIO12	SPI MISO
D7	GPIO13	SPI MOSI
D8	GPIO15	SPI CS

Best Practices

1. Use secrets.yaml

Never hardcode passwords in your main configuration files, especially if you commit them to Git. Use a secrets.yaml file.

secrets.yaml:

wifi_ssid: "MyHomeNetwork"
wifi_password: "SuperSecretPassword"

living-room.yaml:

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

2. Static IP Address

Assigning a static IP can make connections faster and more reliable, although mDNS (.local address) usually works well.

wifi:
  # ... existing config ...
  manual_ip:
    static_ip: 192.168.1.50
    gateway: 192.168.1.1
    subnet: 255.255.255.0

3. Safe Mode / Fallback

Always keep the captive_portal and ap (Access Point) configuration. If your WiFi credentials change or the device cannot connect, it will spawn its own WiFi network that you can connect to and upload a new configuration.

4. Power Management

The Wemos D1 Mini has a small 3.3V regulator.

• Do not power high-current devices (like motors or long LED strips) directly from the 3.3V pin.
• Use the 5V pin (connected to USB power) for relays or sensors that support 5V, or use an external power supply.

5. Logging

Keep the logger: component enabled. When debugging, you can view logs wirelessly:

esphome logs living-room.yaml

Example: Adding a DHT11 Sensor

Connect a DHT11 sensor to pin D2 (GPIO4).

sensor:
  - platform: dht
    pin: D2
    temperature:
      name: "Living Room Temperature"
    humidity:
      name: "Living Room Humidity"
    update_interval: 60s