Added new bluetooth samples

snippets/bluetooth/led/code1.txt

@@ -0,0 +1,6 @@
+static ssize_t recv(struct bt_conn *conn, const struct bt_gatt_attr *attr, const void *buf, uint16_t len, uint16_t offset, uint8_t flags)
+{
+	led_update();
+
+	return 0;
+}

snippets/bluetooth/led/code2.txt

@@ -0,0 +1,17 @@
+
+
+/* --------------------------- */
+/*              LED            */
+/* --------------------------- */
+/*
+Example:
+
+err = led_init();
+if (err) {
+	return 0;
+}
+*/
+/* --------------------------- */
+/*            End LED          */
+/* --------------------------- */
+

snippets/bluetooth/led/led_svc.c

@@ -0,0 +1,52 @@
+/** @file
+ *  @brief Button Service sample
+ */
+
+/*
+ * Copyright (c) 2019 Marcio Montenegro <mtuxpe@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "led_svc.h"
+
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_REGISTER(led_svc);
+
+static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(DT_ALIAS(led0), gpios);
+static bool led_state; /* Tracking state here supports GPIO expander-based LEDs. */
+static bool led_ok;
+
+void led_update(void)
+{
+	if (!led_ok) {
+		return;
+	}
+
+	led_state = !led_state;
+	LOG_INF("Turn %s LED", led_state ? "on" : "off");
+	gpio_pin_set(led.port, led.pin, led_state);
+}
+
+int led_init(void)
+{
+	int ret;
+
+	led_ok = gpio_is_ready_dt(&led);
+	if (!led_ok) {
+		LOG_ERR("Error: LED on GPIO %s pin %d is not ready",
+			led.port->name, led.pin);
+		return -ENODEV;
+	}
+
+	ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_INACTIVE);
+	if (ret < 0) {
+		LOG_ERR("Error %d: failed to configure GPIO %s pin %d",
+			ret, led.port->name, led.pin);
+	}
+
+	return ret;
+}

snippets/bluetooth/led/led_svc.h

@@ -0,0 +1,25 @@
+/** @file
+ *  @brief LED Service sample
+ */
+
+/*
+ * Copyright (c) 2019 Marcio Montenegro <mtuxpe@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ST_BLE_SENSOR_LED_SVC_H_
+#define ST_BLE_SENSOR_LED_SVC_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void led_update(void);
+int led_init(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif