Grow Fingerprint Reader

The fingerprint_grow component allows you to use your R307, R503, R503-RGB, ZFM-20, … fingerprint sensors with ESPHome.

../_images/r307-full.jpg

R307/ZFM-20 Optical Fingerprint Reader (datasheet, Adafruit). Image by Adafruit.

../_images/r503-full.jpg

R503 Capacitive Fingerprint Reader with Bi-Color Aura LED (datasheet, Adafruit). Image by Adafruit.

Component/Hub

The reader can be powered by the 3.3V output of an NodeMCU. As the communication with the reader is done using UART (default baud rate is 57600), you need to have an UART bus in your configuration with the rx_pin connected to the reader’s TX and the tx_pin connected to the reader’s RX.

If available on your reader model, it’s recommended to connect 3.3VT (touch induction power supply) & 3.3V to 3.3V; WAKEUP (finger detection signal) to a free GPIO pin and define it with the sensing_pin option to allow the polling function to quickly return when there’s no finger on the reader.

# Example configuration entry
fingerprint_grow:
  sensing_pin: GPIOXX
  sensor_power_pin:
      number: GPIOXX
      inverted: true
  idle_period_to_sleep: 5s

  on_finger_scan_start:
    ...
  on_finger_scan_matched:
    ...
  on_finger_scan_unmatched:
    ...
  on_finger_scan_misplaced:
    ...
  on_finger_scan_invalid:
    ...
  on_enrollment_scan:
    ...
  on_enrollment_done:
    ...
  on_enrollment_failed:
    ...

Configuration variables:

The configuration is made up of three parts: The central component, optional individual sensors, and the optional enrolling binary sensor.

Base Configuration:

  • uart_id (Optional, ID): Manually specify the ID of the UART hub.

  • id (Optional, ID): Manually specify the ID used for code generation.

  • sensing_pin (Optional, Pin Schema): Pin connected to the reader’s finger detection signal (WAKEUP) output.

  • sensor_power_pin (Optional, Pin Schema): Output pin responsible for toogling the sensor power on and off.

  • password (Optional, int): Password to use for authentication. Defaults to 0x00.

  • new_password (Optional, int): Sets a new password to use for authentication. See Setting a New Password for more information.

  • idle_period_to_sleep (Optional, Time): The sensor idle period to wait before powering it off (sleep). Defaults to 5s. See Sleep Mode for more information.

  • on_finger_scan_start (Optional, Automation): An action to be performed when the finger touches the sensor. See on_finger_scan_start Trigger.

  • on_finger_scan_matched (Optional, Automation): An action to be performed when an enrolled fingerprint is scanned. See on_finger_scan_matched Trigger.

  • on_finger_scan_unmatched (Optional, Automation): An action to be performed when an unknown fingerprint is scanned. See on_finger_scan_unmatched Trigger.

  • on_finger_scan_misplaced (Optional, Automation): An action to be performed when the finger is not entirely touching the sensor. See on_finger_scan_misplaced Trigger.

  • on_finger_scan_invalid (Optional, Automation): An action to be performed when the scan of a fingerprint failed. See on_finger_scan_invalid Trigger.

  • on_enrollment_scan (Optional, Automation): An action to be performed when a fingerprint is scanned during enrollment. See on_enrollment_scan Trigger.

  • on_enrollment_done (Optional, Automation): An action to be performed when a fingerprint is enrolled. See on_enrollment_done Trigger.

  • on_enrollment_failed (Optional, Automation): An action to be performed when a fingerprint enrollment failed. See on_enrollment_failed Trigger.

Binary Sensor

Configuration variables:

Sensor

  • fingerprint_count: The number of enrolled fingerprints stored on the reader. All options from Sensor.

  • last_finger_id: The last matched enrolled fingerprint as set by on_finger_scan_matched Trigger. All options from Sensor.

  • last_confidence: The last matched confidence as set by on_finger_scan_matched Trigger. All options from Sensor.

  • status: The integer representation of the internal status register of the reader. All options from Sensor.

  • capacity: The fingerprint storage capacity of the reader. All options from Sensor.

  • security_level: The integer representation of the currently configured security level of the reader. Higher security levels reduce the false acceptance rate (FAR) at the expense of increasing the false rejection rate (FRR). Range is 1 (lowest) to 5 (highest). All options from Sensor.

Sleep Mode

The sensor idle power consumption is roughly 20mA. If you plan to keep the device running continuously, it is wise to implement the Sleep Mode, which puts the sensor to sleep (power off) a few seconds after the last communication (configurable with idle_period_to_sleep). It can only be implemented along with the Touch Sensing Feature, since it uses the touch feedback to wake up the sensor. To implement this feature, you will need one more free GPIO pin to toggle the sensor power on and off and two external components: a 10kOhms resistor and a PNP transistor (like a BC327).

This is a wiring example for the R503 and below you can find the respective configuration:

../_images/fingeprint_grow-sleep_mode_wiring.jpg
uart:
  rx_pin: GPIOXX
  tx_pin: GPIOXX
  baud_rate: 57600

fingerprint_grow:
  sensing_pin: GPIOXX
  sensor_power_pin:
      number: GPIOXX
      inverted: true
  idle_period_to_sleep: 5s

Setting a New Password

Warning

Forgetting the password will render your fingerprint reader unusable!

You can set a new password for your fingerprint reader using the new_password: configuration option. The password is defined as a 32-bit unsigned integer.

fingerprint_grow:
  password: 0x275FE3D2      # Existing password, can be omitted if it's the default of 0x00
  new_password: 0x72AB96CD  # New password

The new_password: configuration option is meant to be compiled, flashed to the ESP device and run once, after which it’s removed and the new password is defined in the password: configuration option to be compiled and flashed again.

fingerprint_grow:
  password: 0x72AB96CD      # Update the existing password with the new one

on_finger_scan_start Trigger

With this configuration option, you can trigger an automation when a finger is detected touching the sensor. Very useful to indicate to the user via AuraLed that the sensor has detected the finger touch and will perform the scan. This trigger will only activate if your fingerprint sensor is configured with the sensing_pin option.

on_finger_scan_start:
  - fingerprint_grow.aura_led_control:
      state: ALWAYS_ON
      color: GREEN
      speed: 0
      count: 0

on_finger_scan_invalid Trigger

With this configuration option you can write complex automations whenever a scan fails, e.g. when the finger is not placed correctly on the reader. This is different from on_finger_scan_unmatched which is triggered when an unknown fingerprint is scanned. This option works best with the sensing_pin option defined.

on_finger_scan_invalid:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: "Invalid finger"

on_finger_scan_matched Trigger

With this configuration option you can write complex automations whenever a finger scan is matched to an enrolled fingerprint. To use the variables, use a lambda template, the matched slot number and the confidence are available inside that lambda under the variables named finger_id and confidence.

on_finger_scan_matched:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: !lambda 'return "Authorized finger " + to_string(finger_id) + ", confidence " + to_string(confidence);'
  # Pushing a tag_scanned event based on finger_id only if confidence is greater than 50
  - if:
      condition:
        lambda: 'return confidence > 50;'
      then:
        - homeassistant.tag_scanned: !lambda |-
            switch (finger_id) {
              case 0:
                return "person_a";
              case 1:
                return "person_b";
              ...
              default:
                return "person_unknown";
            }

on_finger_scan_unmatched Trigger

With this configuration option you can write complex automations whenever an unknown fingerprint is scanned.

on_finger_scan_unmatched:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: "Unauthorized finger"

on_finger_scan_misplaced Trigger

With this configuration option, you can create automations for situations when the finger is in contact with the sensor but not fully covering it, enabling you to perform a successful scan. This trigger will only activate if your fingerprint sensor is configured with the sensing_pin option. It serves as a useful indicator to alert the user when their touch on the sensor is insufficient.

on_finger_scan_misplaced:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: "Misplaced finger"

on_enrollment_scan Trigger

With this configuration option you can write complex automations whenever a finger is scanned during enrollment. To use the variables, use a lambda template, the scan number and the slot number to be enrolled into are available inside that lambda under the variables named scan_num and finger_id.

on_enrollment_scan:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: !lambda 'return "Enrolling into slot " + to_string(finger_id) + ", scanned " + to_string(scan_num) + " time(s)";'

on_enrollment_done Trigger

With this configuration option you can write complex automations whenever a finger is successfully enrolled. To use the variables, use a lambda template, the slot number enrolled into is available inside that lambda under the variable named finger_id.

on_enrollment_done:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: !lambda 'return "Enrolled into slot " + to_string(finger_id);'

on_enrollment_failed Trigger

With this configuration option you can write complex automations whenever a finger failed to be enrolled. To use the variables, use a lambda template, the slot number that failed to be enrolled into is available inside that lambda under the variable named finger_id.

on_enrollment_failed:
  - text_sensor.template.publish:
      id: fingerprint_state
      state: !lambda 'return "Failed to enroll into slot " + to_string(finger_id);'
  # Retry enrollment into the same slot
  - delay: 3s
  - text_sensor.template.publish:
      id: fingerprint_state
      state: !lambda 'return "Retrying enrollment into slot " + to_string(finger_id) + " in 3 seconds...";'
  - delay: 3s
  - fingerprint_grow.enroll: !lambda 'return finger_id;'

fingerprint_grow.enroll Action

Starts the fingerprint enrollment process on the slot number defined.

on_...:
  then:
    - fingerprint_grow.enroll:
        finger_id: 0
        num_scans: 2
    # Shorthand
    - fingerprint_grow.enroll: 0
    # Update the template text sensor for visual feedback
    - text_sensor.template.publish:
        id: fingerprint_state
        state: "Place a finger on the reader"

Configuration options:

  • finger_id (Required, int, templatable): The slot number to enroll the new fingerprint into. Limited to the fingerprint capacity available on the reader.

  • num_scans (Optional, int, templatable): Number of times to scan the finger to be enrolled. Limited to the number of character buffers available on the reader. Defaults to 2.

fingerprint_grow.cancel_enroll Action

Cancels the current fingerprint enrollment process. Triggers the on_enrollment_failed trigger.

on_...:
  then:
    - fingerprint_grow.cancel_enroll:

fingerprint_grow.delete Action

Removes the enrolled fingerprint from the slot number defined.

on_...:
  then:
    - fingerprint_grow.delete:
        finger_id: 0
    # Shorthand
    - fingerprint_grow.delete: 0

Configuration options:

  • finger_id (Required, int, templatable): The slot number of the enrolled fingerprint to delete.

fingerprint_grow.delete_all Action

Removes all enrolled fingerprints.

on_...:
  then:
    - fingerprint_grow.delete_all:

fingerprint_grow.led_control Action

Turns on or off the LED on the reader. Only available on select models. If you have the R503 or R503-RGB use fingerprint_grow.aura_led_control Action instead.

on_...:
  then:
    - fingerprint_grow.led_control:
        state: ON
    # Shorthand
    - fingerprint_grow.led_control: ON

Configuration options:

  • state (Required, boolean, templatable): The state to set the LED.

fingerprint_grow.aura_led_control Action

Controls the Aura LED on the reader. Only available on select models. NOTE: The R503 has 2 variants with different LED colour options.

on_...:
  then:
    - fingerprint_grow.aura_led_control:
        state: BREATHING
        speed: 100
        color: BLUE
        count: 2
# Sample Aura LED config for all reader triggers
fingerprint_grow:
  on_finger_scan_start:
    - fingerprint_grow.aura_led_control:
        state: ALWAYS_ON
        color: GREEN
        speed: 0
        count: 0
  on_finger_scan_matched:
    - fingerprint_grow.aura_led_control:
        state: BREATHING
        speed: 200
        color: BLUE
        count: 1
  on_finger_scan_unmatched:
    - fingerprint_grow.aura_led_control:
        state: FLASHING
        speed: 25
        color: RED
        count: 2
  on_finger_scan_misplaced:
    - fingerprint_grow.aura_led_control:
        state: FLASHING
        speed: 25
        color: PURPLE
        count: 2
  on_enrollment_scan:
    - fingerprint_grow.aura_led_control:
        state: FLASHING
        speed: 25
        color: BLUE
        count: 2
    - fingerprint_grow.aura_led_control:
        state: ALWAYS_ON
        speed: 0
        color: PURPLE
        count: 0
  on_enrollment_done:
    - fingerprint_grow.aura_led_control:
        state: BREATHING
        speed: 100
        color: BLUE
        count: 2
  on_enrollment_failed:
    - fingerprint_grow.aura_led_control:
        state: FLASHING
        speed: 25
        color: RED
        count: 4
on...:
  then:
    - fingerprint_grow.enroll: ...
    - fingerprint_grow.aura_led_control:
        state: ALWAYS_ON
        speed: 0
        color: PURPLE
        count: 0

Configuration options:

  • state (Required, string, templatable): The state to set the LED. One of BREATHING, FLASHING, ALWAYS_ON, ALWAYS_OFF, GRADUAL_ON and GRADUAL_OFF.

  • speed (Required, int, templatable): The duration each cycle lasts, a factor of 10ms. Only relevant for BREATHING, FLASHING, GRADUAL_ON and GRADUAL_OFF states. The total duration is defined by 10ms * speed * count. Range is 0 to 255.

  • color (Required, string, templatable): The LED color to activate. For R503, one of RED, BLUE and PURPLE. For R503-RGB, one of RED, BLUE, PURPLE, GREEN, YELLOW, CYAN and WHITE.

  • count (Required, int, templatable): How many times to repeat the pattern. Only relevant for BREATHING and FLASHING states. 0 for infinite, or 1 to 255.

All actions

  • id (Optional, ID): Manually specify the ID of the Grow fingerprint reader if you have multiple components.

Test setup

With the following code you can quickly setup a node and use Home Assistant’s action in the developer tools. E.g. for calling fingerprint_grow.enroll select the action esphome.test_node_enroll and in action data enter

{ "finger_id": 0, "num_scans": 2 }

Sample code

uart:
  rx_pin: GPIOXX
  tx_pin: GPIOXX
  baud_rate: 57600

fingerprint_grow:
  sensing_pin: GPIOXX
  on_finger_scan_invalid:
    - homeassistant.event:
        event: esphome.test_node_finger_scan_invalid
  on_finger_scan_matched:
    - homeassistant.event:
        event: esphome.test_node_finger_scan_matched
        data:
          finger_id: !lambda 'return finger_id;'
          confidence: !lambda 'return confidence;'
  on_finger_scan_unmatched:
    - homeassistant.event:
        event: esphome.test_node_finger_scan_unmatched
  on_finger_scan_misplaced:
    - homeassistant.event:
        event: esphome.frontdoor_finger_scan_misplaced
  on_enrollment_scan:
    - homeassistant.event:
        event: esphome.test_node_enrollment_scan
        data:
          finger_id: !lambda 'return finger_id;'
          scan_num: !lambda 'return scan_num;'
  on_enrollment_done:
    - homeassistant.event:
        event: esphome.test_node_enrollment_done
        data:
          finger_id: !lambda 'return finger_id;'
  on_enrollment_failed:
    - homeassistant.event:
        event: esphome.test_node_enrollment_failed
        data:
          finger_id: !lambda 'return finger_id;'

api:
  actions:
  - action: enroll
    variables:
      finger_id: int
      num_scans: int
    then:
      - fingerprint_grow.enroll:
          finger_id: !lambda 'return finger_id;'
          num_scans: !lambda 'return num_scans;'
  - action: cancel_enroll
    then:
      - fingerprint_grow.cancel_enroll:
  - action: delete
    variables:
      finger_id: int
    then:
      - fingerprint_grow.delete:
          finger_id: !lambda 'return finger_id;'
  - action: delete_all
    then:
      - fingerprint_grow.delete_all:

See Also