Presence Sensor Project with ESP32-S3 Board and mmWave

ESPHome configuration for the HMMD mmWave Sensor S3KM1110 on an ESP32-S3 board.

Tested with: ESPHome version 2025.2.2

Features

• MQTT integration for Home Assistant
• Optional native Home Assistant API (disabled by default)
• Status LED via WS2812
• WiFi fallback Access Point
• Easy customization via secrets_template.yaml

Getting Started

1. Prepare secrets.yaml

Copy the template and add your details:

cp secrets_template.yaml secrets.yaml

2. Adjust device name (optional)

Change the device name and friendly name at the top of the YAML:

substitutions:
  device_name: presence_sensor
  friendly_name: "Presence Sensor"

3. Flash your ESP32-S3

Use ESPHome CLI or Home Assistant ESPHome Add-On.

4. Optional: Enable Home Assistant API

Uncomment the api: section and provide the API encryption key in secrets.yaml if you prefer native API over MQTT.

# api:
#   encryption:
#     key: !secret api_encryption_key

5. Add to Home Assistant

If using MQTT with discovery enabled, your device will appear automatically.

Hardware

This configuration was tested with the following hardware:

• ✅ HMMD mmWave Sensor (S3KM1110)

  • Amazon Link
  • Waveshare Wiki

• ✅ ESP32-S3 board (Waveshare ESP32-S3 Zero)

  • Amazon Link
  • Waveshare Wiki

Wiring:

• ESP32-S3 TX (GPIO7) → Sensor RX
• ESP32-S3 RX (GPIO6) → Sensor TX
• Sensor VCC → 3.3V on ESP32-S3
• Sensor GND → GND on ESP32-S3
• WS2812 LED Data → GPIO21 on ESP32-S3

License

MIT License