Card and PIN: an access automation in Home Assistant

The bridge reports every card and every PIN result over MQTT. One automation checks the card, waits up to 15 seconds for the correct PIN, opens the lock and gives the reader a green or red signal.

A card alone can be lost or passed on. A PIN alone can be watched over someone’s shoulder. Together they are a second factor: the door opens only for someone who has the card and knows the code. This guide builds exactly that.

What you need

• a KLOKL Bridge with an OSDP reader that has a keypad
• Home Assistant with an MQTT broker, for example the Mosquitto add-on
• a lock or relay that Home Assistant can switch

The topics involved

Every topic starts with the device ID of your bridge. You find it in the web interface of the bridge and in Home Assistant under the device. In this example it is osdp-reader-3f9a12.

• …/card_data: number of the card that was read
• …/pin_status: “Code akzeptiert” or “Code nicht akzeptiert” after the user presses #
• …/cmd/feedback_ok: green LED and beeper on the reader
• …/cmd/feedback_denied: red signal on the reader

Step 1: set the code

The bridge compares the PIN itself, so the code never travels over the network when someone types it. Set the code once: in Home Assistant the bridge appears with a text field “Access Code”; enter the code there. Alternatively publish it to …/cmd/access_code.

Step 2: the automation

Create a new automation, switch to YAML mode and paste the following. Replace the device ID, the card numbers and the lock entity with your own.

1alias: Front door: card and PIN
2mode: single
3triggers:
4  - trigger: mqtt
5    topic: osdp-reader-3f9a12/card_data
6conditions:
7  - condition: template
8    value_template: "{{ trigger.payload in ['0004958372', '0004958373'] }}"
9actions:
10  - wait_for_trigger:
11      - trigger: mqtt
12        topic: osdp-reader-3f9a12/pin_status
13        payload: "Code akzeptiert"
14    timeout: "00:00:15"
15    continue_on_timeout: true
16  - if:
17      - condition: template
18        value_template: "{{ wait.trigger is not none }}"
19    then:
20      - action: lock.unlock
21        target:
22          entity_id: lock.front_door
23      - action: mqtt.publish
24        data:
25          topic: osdp-reader-3f9a12/cmd/feedback_ok
26          payload: ""
27    else:
28      - action: mqtt.publish
29        data:
30          topic: osdp-reader-3f9a12/cmd/feedback_denied
31          payload: ""
Copy

What happens

1. A card is held to the reader. If its number is not on the list, nothing happens.
2. For a known card the automation waits up to 15 seconds for “Code akzeptiert”.
3. Correct PIN in time: the lock opens and the reader shows green.
4. Wrong PIN or too late: the reader shows red and the door stays closed.

Tips for everyday use

• Find card numbers by holding each card to the reader once and reading the sensor “Card Data” in Home Assistant.
• Keep the list of allowed cards in one place, for example in a template sensor or a helper, if several automations use it.
• For a card-only entrance, leave out the waiting step and unlock directly.
• Add a notification on “Code nicht akzeptiert” if you want to know about failed attempts.

Wiring and first start are described in the documentation. Why the bridge uses OSDP at all: OSDP instead of Wiegand.