Car Arrival Detection via BLE in Home Assistant (Driveway Automation, Gate/Lights, Reliable Logic)

“Car arrival detection” is one of the most useful automations you can build because it’s faster and more reliable than GPS when done properly. The idea is simple:

Put a BLE beacon in the car (or use a car BLE adapter / key tag)
Place an ESP32 Bluetooth Proxy near the driveway/entrance
When the proxy starts seeing the beacon strongly → the car is home
Trigger automations: open gate, switch on driveway lights, disarm alarm, etc.

This article shows a reliable setup using BLE + smart timeouts so it doesn’t false-trigger when you walk near the front door.

1. Choose Your BLE “Car Tag”

Best option: dedicated BLE beacon

A small iBeacon/Eddystone tag powered by a coin cell is ideal because it advertises consistently.

Pros

Predictable
Battery lasts months to years depending on interval
Works even if your phone is off

Cons

You must remember to leave it in the car

OK option: phone in the car

Not recommended for this specific use case because phones throttle BLE adverts and may not be consistent when the screen is off.

Practical tip

Place the beacon:

in the glovebox
under the dashboard (not wrapped in metal)
in the center console

Avoid placing it inside a metal tin/box or behind thick metal shielding.

2. ESP32 Bluetooth Proxy Placement (Make it Accurate)

For car arrival you want the “arrival zone” to be very localized.

Place a dedicated proxy:

near the garage door
behind a front window facing the driveway
near the gate motor enclosure (if it has Wi-Fi)
in the hallway closest to the driveway wall

Important: you want strong RSSI only when the car is actually nearby, not when you’re inside the living room.

If you get false triggers from inside the house:

move the proxy closer to the driveway wall/window
reduce BLE sensitivity by using a stronger RSSI threshold (next section)

3. Create a Reliable “Car Present” Sensor (RSSI + Time)

You want a binary sensor:

binary_sensor.car_present_ble

The best logic is:

ON if RSSI is stronger than a threshold for ~15–30 seconds
OFF only if not seen for a few minutes (prevents flapping)

3.1 If you have a single driveway proxy RSSI sensor

Assume you have:

sensor.car_beacon_rssi_driveway

Create a binary sensor:

template:
  - binary_sensor:
      - name: "Car Present (BLE)"
        unique_id: car_present_ble
        state: >
          {{ states('sensor.car_beacon_rssi_driveway') | float(-999) > -75 }}
        delay_on: "00:00:20"
        delay_off: "00:03:00"
        device_class: presence

Threshold tuning

Start with -75 dBm
If it triggers too easily (car not actually in driveway) → use -70 or -65
If it misses arrivals → use -80

3.2 If you only have “seen/not seen” (no RSSI)

You can still do it, but it’s less precise:

ON when seen
OFF if not seen for 5 minutes

This tends to false-trigger if the beacon is heard through walls.

RSSI-based is much better for car arrival.

4. Arrival vs “I’m Walking Near the Proxy” (Avoid False Gate Opens)

This is the biggest trap.

If you carry a beacon on your keys and your driveway proxy hears it, you don’t want the gate to open when you walk near the front door.

Solutions:

A) Use a car-only beacon

Don’t reuse your personal beacon. Use a dedicated beacon that lives permanently in the car.

B) Add speed/sequence logic (recommended)

Car arrival looks like:

RSSI goes from weak → strong quickly
Then stays strong

Walking inside the house is usually:

weaker and more inconsistent
often doesn’t cross a strong threshold

The delay_on + tighter threshold handles most of this.

C) Add “gate can open only if you’re away”

Only auto-open when:

house is in away mode
OR alarm is armed away
OR nobody is home

That prevents accidental opening when you’re already home.

5. Home Assistant Automation: Driveway Lights + Gate

5.1 Turn on driveway lights when car arrives

automation:
  - alias: "Car Arrival - Driveway Lights"
    trigger:
      - platform: state
        entity_id: binary_sensor.car_present_ble
        to: "on"
    action:
      - service: light.turn_on
        target:
          entity_id: light.driveway
      - delay: "00:10:00"
      - service: light.turn_off
        target:
          entity_id: light.driveway

5.2 Open gate when car arrives (with safety conditions)

Only open if:

it’s closed
and you’re not already home (or alarm is armed away)

automation:
  - alias: "Car Arrival - Open Gate"
    trigger:
      - platform: state
        entity_id: binary_sensor.car_present_ble
        to: "on"
    condition:
      - condition: state
        entity_id: cover.gate
        state: "closed"
      - condition: state
        entity_id: binary_sensor.presence_home_final
        state: "off"
    action:
      - service: cover.open_cover
        target:
          entity_id: cover.gate

Replace binary_sensor.presence_home_final with your actual home/away sensor (from your BLE+Wi-Fi setup).

6. Departure Detection (Optional)

You can also detect when the car leaves:

car_present_ble turns OFF after 3 minutes
trigger “away mode”, or close gate after delay (careful)

Example: turn off driveway lights when car leaves:

automation:
  - alias: "Car Departure - Lights Off"
    trigger:
      - platform: state
        entity_id: binary_sensor.car_present_ble
        to: "off"
    action:
      - service: light.turn_off
        target:
          entity_id: light.driveway

7. Tuning Checklist (fast)

If it triggers too early:

Increase RSSI threshold (e.g. -75 → -70)
Move proxy closer to driveway-facing wall/window
Add delay_on to 30 seconds

If it misses arrivals:

Lower threshold (-75 → -80)
Add a second proxy nearer to driveway
Ensure beacon isn’t shielded by metal

If it flaps on/off:

Increase delay_off to 5–8 minutes

8. Best-Practice Setup Summary

The “this just works” configuration is:

Dedicated beacon permanently in the car
One ESP32 proxy near driveway window/entrance
RSSI threshold around -70 to -80
delay_on: 20s, delay_off: 3–5m
Gate automation guarded by home/away condition

That combination is fast, local, and doesn’t depend on GPS or cloud services.