GROW R502-A Fingerprint Sensor

Overview

This sample has the below functionalities:

  1. Sensor LED is controlled using led APIs from zephyr subsystem.

  2. Shows the number of fingerprints stored in the sensor.

  3. Shows the sensor device’s configurations like baud rate, library size, address and data packet size in UART frame.

  4. When SENSOR_ATTR_RECORD_FREE_IDX is set then it search for free index in sensor library.

  5. When SENSOR_ATTR_RECORD_ADD is set then it adds a new fingerprint to the sensor.

  6. When SENSOR_ATTR_RECORD_FIND is set then it tries to find a match for the input fingerprint. On finding a match it returns ID and confidence.

  7. When SENSOR_ATTR_RECORD_DEL is set then it deletes a fingerprint from the sensor.

Note: Fingerprint add functionality work only when SENSOR_TRIG_TOUCH is set.

Wiring

This sample uses an external breakout for the sensor. A devicetree overlay must be provided to identify the UART bus and the GPIO used to control the sensor. Sensor can be powered using mentioned optional GPIO.

References

For more information about the GROW_R502A Fingerprint Sensor see http://en.hzgrow.com/product/143.html

Building and Running

After providing a devicetree overlay that specifies the sensor location, build this sample app using:

# From the root of the zephyr repository
west build -b esp32_devkitc_wroom/esp32/procpu samples/sensor/grow_r502a
west flash

Sample Output

*** Booting Zephyr OS build v3.6.0-3147-g8ae1a2e2718e ***
template count : 4
baud 57600
addr 0xffffffff
lib_size 200
data_pkt_size 128
Fingerprint Deleted at ID #3
Fingerprint template free idx at ID #3
Waiting for valid finger to enroll as ID #3
Place your finger
Fingerprint successfully stored at #3
template count : 4
Matched ID : 2
confidence : 110
<repeats endlessly>

See also

Sensor Interface