BLE scan example added

23_ble_scan/Makefile

@@ -0,0 +1,9 @@
+#
+# This is a project Makefile. It is assumed the directory this Makefile resides in is a
+# project subdirectory.
+#
+
+PROJECT_NAME := ble_scan
+
+include $(IDF_PATH)/make/project.mk
+

23_ble_scan/main/main.c

@@ -0,0 +1,142 @@
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
+#include "nvs_flash.h"
+#include "esp_err.h"
+#include "esp_log.h"
+
+#include "esp_bt.h"
+#include "esp_bt_main.h"
+#include "esp_gap_ble_api.h"
+
+
+// array of found devices
+#define MAX_DISCOVERED_DEVICES 50
+esp_bd_addr_t discovered_devices[MAX_DISCOVERED_DEVICES];
+int discovered_devices_num = 0;
+
+// scan parameters
+static esp_ble_scan_params_t ble_scan_params = {
+		.scan_type              = BLE_SCAN_TYPE_ACTIVE,
+		.own_addr_type          = BLE_ADDR_TYPE_PUBLIC,
+		.scan_filter_policy     = BLE_SCAN_FILTER_ALLOW_ALL,
+		.scan_interval          = 0x50,
+		.scan_window            = 0x30
+	};
+
+// check if the device was already discovered
+bool alreadyDiscovered(esp_bd_addr_t address) {
+
+	bool found = false;
+
+	for(int i = 0; i < discovered_devices_num; i++) {
+
+		for(int j = 0; j < ESP_BD_ADDR_LEN; j++)
+			found = (discovered_devices[i][j] == address[j]);
+
+		if(found) break;
+	}
+
+	return found;
+}
+
+// add a new device to the list
+void addDevice(esp_bd_addr_t address) {
+
+	discovered_devices_num++;
+	if(discovered_devices_num > MAX_DISCOVERED_DEVICES) return;
+
+	for(int i = 0; i < ESP_BD_ADDR_LEN; i++)
+		discovered_devices[discovered_devices_num - 1][i] = address[i];
+}
+
+// GAP callback
+static void esp_gap_cb(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param)
+{
+    switch (event) {
+
+		case ESP_GAP_BLE_SCAN_PARAM_SET_COMPLETE_EVT: 
+
+			printf("ESP_GAP_BLE_SCAN_PARAM_SET_COMPLETE_EVT\n");
+			if(param->scan_param_cmpl.status == ESP_BT_STATUS_SUCCESS) {
+				printf("Scan parameters set, start scanning for 10 seconds\n\n");
+				esp_ble_gap_start_scanning(10);
+			}
+			else printf("Unable to set scan parameters, error code %d\n\n", param->scan_param_cmpl.status);
+			break;
+
+		case ESP_GAP_BLE_SCAN_START_COMPLETE_EVT:
+
+			printf("ESP_GAP_BLE_SCAN_START_COMPLETE_EVT\n");
+			if(param->scan_start_cmpl.status == ESP_BT_STATUS_SUCCESS) {
+				printf("Scan started\n\n");
+			}
+			else printf("Unable to start scan process, error code %d\n\n", param->scan_start_cmpl.status);
+			break;
+
+		case ESP_GAP_BLE_SCAN_RESULT_EVT:
+
+			if(param->scan_rst.search_evt == ESP_GAP_SEARCH_INQ_RES_EVT) {
+
+				if(!alreadyDiscovered(param->scan_rst.bda)) {
+
+					printf("ESP_GAP_BLE_SCAN_RESULT_EVT\n");
+					printf("Device found: ADDR=");
+					for(int i = 0; i < ESP_BD_ADDR_LEN; i++) {
+						printf("%02X", param->scan_rst.bda[i]);
+						if(i != ESP_BD_ADDR_LEN -1) printf(":");
+					}
+
+					printf("\n\n");
+					addDevice(param->scan_rst.bda);
+				}
+
+			}
+			else if(param->scan_rst.search_evt == ESP_GAP_SEARCH_INQ_CMPL_EVT)
+				printf("Scan complete\n\n");
+			break;
+
+		default:
+
+			printf("Event %d unhandled\n\n", event);
+			break;
+	}
+}
+
+
+void app_main() {
+
+	printf("BT scan\n\n");
+
+	// set components to log only errors
+	esp_log_level_set("*", ESP_LOG_ERROR);
+
+	// initialize nvs
+	ESP_ERROR_CHECK(nvs_flash_init());
+	printf("- NVS init ok\n");
+
+	// release memory reserved for classic BT (not used)
+	ESP_ERROR_CHECK(esp_bt_controller_mem_release(ESP_BT_MODE_CLASSIC_BT));
+	printf("- Memory for classic BT released\n");
+
+	// initialize the BT controller with the default config
+	esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
+    esp_bt_controller_init(&bt_cfg);
+	printf("- BT controller init ok\n");
+
+	// enable the BT controller in BLE mode
+    esp_bt_controller_enable(ESP_BT_MODE_BLE);
+	printf("- BT controller enabled in BLE mode\n");
+
+	// initialize Bluedroid library
+	esp_bluedroid_init();
+    esp_bluedroid_enable();
+	printf("- Bluedroid initialized and enabled\n");
+
+	// register GAP callback function
+	ESP_ERROR_CHECK(esp_ble_gap_register_callback(esp_gap_cb));
+	printf("- GAP callback registered\n\n");
+
+	// configure scan parameters
+	esp_ble_gap_set_scan_params(&ble_scan_params);
+}