Car Presence Detection System

This project utilizes an ESPHome configuration to detect the presence of a car on a parking spot using a Wemos D1 Mini (ESP8266) board and an ultrasonic sensor. The system determines the car's presence based on measured distances and provides occupancy feedback.

Features

• Ultrasonic Distance Measurement: Uses an ultrasonic sensor to measure distances and identify if a car is present within a defined range.
• Wi-Fi Connectivity: Connects to your Wi-Fi network for remote monitoring via Home Assistant.
• Fallback AP Mode: Provides a fallback access point for configuration in case of Wi-Fi issues.
• OTA Updates: Enables over-the-air firmware updates for easy maintenance.
• Real-Time Status: Displays IP, MAC address, and firmware version on the dashboard.
• Custom Logic for Presence Detection: Tracks if the distance is within the desired range for a prolonged period.

Hardware Requirements

• Wemos D1 Mini (ESP8266)
• Ultrasonic Sensor (e.g., HC-SR04)
• Connecting Wires
• Power Source (5V)

Connections

Ultrasonic Sensor

• Trigger Pin: Connect to D1 (GPIO5) on the Wemos D1 Mini.
• Echo Pin: Connect to D2 (GPIO4) on the Wemos D1 Mini.
• VCC: Connect to the 5V pin on the Wemos D1 Mini.
• GND: Connect to the GND pin on the Wemos D1 Mini.

Configuration Overview

Substitutions

substitutions:
  name: car-presence-workshop
  friendly_name: "Car Presence Workshop"
  board: d1_mini

• name: Internal name for the ESPHome node.
• friendly_name: Display name for the node.
• board: Specifies the ESP8266 board type.

Main Components

Wi-Fi Settings

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  ap:
    ssid: ${friendly_name} Fallback AP
    password: !secret car_presence_workshop_ap_password

• Connects to your Wi-Fi network using credentials stored in the secrets.yaml file.
• Enables a fallback access point for troubleshooting.

Ultrasonic Sensor Configuration

sensor:
  - platform: ultrasonic
    trigger_pin: D1
    echo_pin: D2
    name: "Ultrasonic Distance"
    update_interval: 10s
    id: ultrasonic_sensor

• Measures distance every 10 seconds using the HC-SR04 sensor.
• trigger_pin and echo_pin: Define GPIO pins connected to the sensor.

Binary Sensors

Car Presence

binary_sensor:
  - platform: template
    name: "Car Presence"
    id: car_presence
    device_class: occupancy
    lambda: |-
      if (id(distance_in_range).state) {
        return true;
      } else {
        return false;
      }

• Determines if a car is present based on the distance_in_range sensor.

Distance In Range

binary_sensor:
  - platform: template
    name: "Distance In Range"
    id: distance_in_range
    internal: true
    lambda: |-
      return false;  # Default state

• Internal sensor to monitor if the measured distance falls within the specified range.

Interval for Presence Detection

interval:
  - interval: 10s
    then:
      - lambda: |-
          static int check_counter = 0;
          float dist = id(ultrasonic_sensor).state;
          if (dist >= 50 && dist <= 200) {  // Replace with your desired range
            check_counter++;
          } else {
            check_counter = 0;
          }

          if (check_counter >= 12) {  // Car present for 2 minutes
            id(distance_in_range).publish_state(true);
          } else {
            id(distance_in_range).publish_state(false);
          }

• Detects the car’s presence if the distance remains in range for at least 2 minutes (12 cycles of 10 seconds).

Additional Features

Text Sensors

text_sensor:
  - platform: version
    name: ESPHome Version - ${friendly_name}
  - platform: wifi_info
    ip_address: 
      name: IP - ${friendly_name}
    mac_addres:
      name: MAC - ${friendly_name}

• Displays firmware version, IP address, and MAC address on the Home Assistant dashboard.

Logger

logger:

• Provides debugging logs.

API and OTA Updates

api:
  encryption:
    key: !secret car_presence_workshop_api_encryption_key

ota:
  - platform: esphome
    password: !secret car_presence_workshop_ota_password

• API: Allows secure communication with Home Assistant.
• OTA: Enables remote firmware updates.

Usage

1. Flashing the Firmware:
   • Compile and upload the ESPHome configuration to the Wemos D1 Mini.
2. Wi-Fi Setup:
   • If preconfigured, the device will connect automatically. Otherwise, use the fallback AP to configure Wi-Fi.
3. Dashboard Integration:
   • View distance readings and car presence status in Home Assistant.
4. Calibrate Distance Range:
   • Adjust the 50 to 200 range in the interval section based on your setup.

Secrets

Ensure the following are defined in your secrets.yaml file:

• wifi_ssid
• wifi_password
• car_presence_workshop_ap_password
• car_presence_workshop_api_encryption_key
• car_presence_workshop_ota_password