samples: sensor: Added sample for grow_r502a fingerprint sensor

Added sample application for grow_r502a fingerprint sensor

Signed-off-by: Dinesh Kumar K <dinesh@linumiz.com>

samples/sensor/grow_r502a/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(grow_r502a)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

samples/sensor/grow_r502a/README.rst

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+.. _grow_r502a:
+
+GROW_R502A Fingerprint Sensor
+#############################
+
+Overview
+********
+
+This sample has the below functionalities:
+
+#. Shows the number of fingerprints stored in the sensor.
+#. When SENSOR_ATTR_RECORD_FREE_IDX is set then it search for free index in sensor library.
+#. When SENSOR_ATTR_RECORD_ADD is set then it adds a new fingerprint to the sensor.
+#. 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.
+#. When SENSOR_ATTR_RECORD_DEL is set then it deletes a fingerprint from the sensor.
+
+Note: Fingerprint add & delete functionalities work only when SENSOR_TRIG_TOUCH is set.
+Tricolored LED in the sensor hardware will, flash on the below conditions:
+
+#. On successful addition or deletion of fingerprint it will flash in blue three times.
+#. On finding a match for the input fingerprint it will flash in purple.
+#. In all other cases it will flash in red.
+
+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:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/sensor/grow_r502a
+   :board: nrf52840dk_nrf52840
+   :goals: build flash
+
+Sample Output
+*************
+
+.. code-block:: console
+
+    *** Booting Zephyr OS build zephyr-v3.1.0-2640-g328bb73113d4  ***
+    template count : 0
+    Fingerprint Deleted at ID #3
+    Fingerprint template free idx at ID #0
+    Waiting for valid finger to enroll as ID #0
+    Place your finger
+    Fingerprint successfully stored at #0
+    template count : 1
+    Matched ID : 0
+    confidence : 170
+    template count : 1
+    Matched ID : 0
+    confidence : 136
+    template count : 1
+    Matched ID : 0
+    confidence : 318
+    <repeats endlessly>

samples/sensor/grow_r502a/boards/esp32.overlay

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+&pinctrl {
+	uart2_default: uart2_default {
+		group1 {
+			pinmux = <UART2_TX_GPIO32>;
+		};
+		group2 {
+			pinmux = <UART2_RX_GPIO33>;
+			bias-pull-up;
+		};
+	};
+};
+
+&uart2 {
+	status = "okay";
+	current-speed = <57600>;
+	pinctrl-0 = <&uart2_default>;
+	pinctrl-names = "default";
+
+	fps {
+		#address-cells=<1>;
+		#size-cells=<0>;
+		grow_r502a@ffffffff {
+			compatible = "hzgrow,r502a";
+			reg = <0xffffffff>;
+			int-gpios = <&gpio1 3 GPIO_ACTIVE_LOW>;
+		};
+	};
+};

samples/sensor/grow_r502a/prj.conf

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+CONFIG_SERIAL=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+
+CONFIG_SENSOR=y
+CONFIG_GROW_R502A_TRIGGER_OWN_THREAD=y

samples/sensor/grow_r502a/sample.yaml

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+#
+# Copyright (c) 2021 Linumiz.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+sample:
+  name: grow_r502a fingerprint sensor sample
+tests:
+  sample.sensor.grow_r502a:
+    tags: sensors
+    harness: sensor
+    build_only: true
+    depends_on: serial
+    filter: dt_compat_enabled("hzgrow,r502a")

samples/sensor/grow_r502a/src/main.c

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+/*
+ * Copyright (c) 2021 Linumiz
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/drivers/uart.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/sensor/grow_r502a.h>
+
+static bool enroll;
+static struct sensor_value fid, val;
+
+static void finger_match(const struct device *dev)
+{
+	struct sensor_value input;
+	int ret;
+
+	ret = sensor_attr_get(dev, SENSOR_CHAN_FINGERPRINT,
+		SENSOR_ATTR_R502A_RECORD_FIND, &input);
+	if (ret != 0) {
+		printk("Sensor attr get failed %d\n", ret);
+		return;
+	}
+	printk("Matched ID : %d\n", input.val1);
+	printk("confidence : %d\n", input.val2);
+}
+
+static void finger_enroll(const struct device *dev)
+{
+	int ret;
+
+	ret = sensor_attr_set(dev, SENSOR_CHAN_FINGERPRINT, SENSOR_ATTR_R502A_RECORD_ADD, &fid);
+
+	if (ret == 0) {
+		printk("Fingerprint successfully stored at #%d\n", fid.val1);
+		enroll = false;
+	}
+}
+
+static void template_count_get(const struct device *dev)
+{
+	int ret;
+
+	ret = sensor_sample_fetch(dev);
+	if (ret < 0) {
+		printk("Sample Fetch Error %d\n", ret);
+		return;
+	}
+	ret = sensor_channel_get(dev, SENSOR_CHAN_FINGERPRINT, &val);
+	if (ret < 0) {
+		printk("Channel Get Error %d\n", ret);
+		return;
+	}
+	printk("template count : %d\n", val.val1);
+}
+
+static void trigger_handler(const struct device *dev,
+			    const struct sensor_trigger *trigger)
+{
+	if (enroll) {
+		finger_enroll(dev);
+	} else {
+		template_count_get(dev);
+		finger_match(dev);
+	}
+}
+
+void main(void)
+{
+	static struct sensor_value del, fid_get;
+	int ret;
+
+	const struct device *dev =  DEVICE_DT_GET_ONE(hzgrow_r502a);
+
+	if (dev ==  NULL) {
+		printk("Error: no device found\n");
+		return;
+	}
+
+	if (!device_is_ready(dev)) {
+		printk("Error: Device %s is not ready\n", dev->name);
+		return;
+	}
+
+	template_count_get(dev);
+
+	del.val1 = 3;
+	ret = sensor_attr_set(dev, SENSOR_CHAN_FINGERPRINT, SENSOR_ATTR_R502A_RECORD_DEL, &del);
+	if (ret != 0) {
+		printk("Sensor attr set failed %d\n", ret);
+		return;
+	}
+	printk("Fingerprint Deleted at ID #%d\n", del.val1);
+
+	ret = sensor_attr_get(dev, SENSOR_CHAN_FINGERPRINT,
+					SENSOR_ATTR_R502A_RECORD_FREE_IDX, &fid_get);
+	if (ret != 0) {
+		printk("Sensor attr get failed %d\n", ret);
+		return;
+	}
+	printk("Fingerprint template free idx at ID #%d\n", fid_get.val1);
+
+	fid.val1 = fid_get.val1;
+	printk("Waiting for valid finger to enroll as ID #%d\n"
+		"Place your finger\n", fid.val1);
+	enroll = true;
+
+	if (IS_ENABLED(CONFIG_GROW_R502A_TRIGGER)) {
+		struct sensor_trigger trig = {
+			.type = SENSOR_TRIG_TOUCH,
+			.chan = SENSOR_CHAN_FINGERPRINT,
+		};
+		ret = sensor_trigger_set(dev, &trig, trigger_handler);
+		if (ret != 0) {
+			printk("Could not set trigger\n");
+			return;
+		}
+	}
+
+}