Wifi

.gitignore

@@ -1,3 +1,4 @@
 .vscode
 build
-sdkconfig.old
+sdkconfig.old
+main/wifi-credentials.h

main/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(SOURCES 
     "main.c"
     "usb-cdc.c"
+    "nvs.c"
     "wifi.c"
 )
 

main/main.c

@@ -1,6 +1,7 @@
 #include <stdint.h>
 #include <esp_log.h>
 #include "usb-cdc.h"
+#include "nvs.h"
 #include "wifi.h"
 
 static const char* TAG = "main";
@@ -9,6 +10,7 @@ void app_main(void) {
     ESP_LOGI(TAG, "start");
 
     usb_cdc_init();
+    nvs_init();
     wifi_init();
 
     ESP_LOGI(TAG, "end");

main/nvs.c

@@ -0,0 +1,11 @@
+#include <nvs_flash.h>
+#include <esp_log.h>
+
+void nvs_init(void) {
+    esp_err_t ret = nvs_flash_init();
+    if(ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+        ESP_ERROR_CHECK(nvs_flash_erase());
+        ret = nvs_flash_init();
+    }
+    ESP_ERROR_CHECK(ret);
+}

main/nvs.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void nvs_init(void);

main/usb-cdc.h

@@ -1,3 +1,3 @@
 #pragma once
 
-void usb_cdc_init(void);
+void usb_cdc_init(void);

main/wifi.c

@@ -1,7 +1,83 @@
 #include <esp_log.h>
+#include <esp_wifi.h>
+#include <freertos/event_groups.h>
+#include "wifi-credentials.h"
 
 static const char* TAG = "wifi";
 
+#if !defined(WIFI_SSID) || !defined(WIFI_PASS)
+#error Create wifi-credentials.h with defined WIFI_SSID and WIFI_PASS
+#endif
+
+#define WIFI_MAXIMUM_RETRY 3
+
+// TODO remove global vars
+static EventGroupHandle_t wifi_event_group;
+#define WIFI_CONNECTED_BIT BIT0
+#define WIFI_FAIL_BIT BIT1
+static int s_retry_num = 0;
+
+static void
+    event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data) {
+    if(event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        esp_wifi_connect();
+    } else if(event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
+        if(s_retry_num < WIFI_MAXIMUM_RETRY) {
+            esp_wifi_connect();
+            s_retry_num++;
+            ESP_LOGI(TAG, "retry to connect to the AP");
+        } else {
+            xEventGroupSetBits(wifi_event_group, WIFI_FAIL_BIT);
+        }
+        ESP_LOGI(TAG, "connect to the AP fail");
+    } else if(event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
+        ip_event_got_ip_t* event = (ip_event_got_ip_t*)event_data;
+        ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));
+        s_retry_num = 0;
+        xEventGroupSetBits(wifi_event_group, WIFI_CONNECTED_BIT);
+    }
+}
+
 void wifi_init(void) {
-    ESP_LOGI(TAG, "Not implemented");
-}
+    wifi_event_group = xEventGroupCreate();
+
+    ESP_ERROR_CHECK(esp_netif_init());
+
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+    esp_netif_create_default_wifi_sta();
+
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+    ESP_ERROR_CHECK(
+        esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL));
+    ESP_ERROR_CHECK(
+        esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL));
+
+    wifi_config_t wifi_config = {
+        .sta = {.ssid = WIFI_SSID, .password = WIFI_PASS},
+    };
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
+    ESP_ERROR_CHECK(esp_wifi_start());
+
+    ESP_LOGI(TAG, "wifi_init_sta finished.");
+
+    /* Waiting until either the connection is established (WIFI_CONNECTED_BIT) or connection failed for the maximum
+     * number of re-tries (WIFI_FAIL_BIT). The bits are set by event_handler() (see above) */
+    EventBits_t bits = xEventGroupWaitBits(
+        wifi_event_group, WIFI_CONNECTED_BIT | WIFI_FAIL_BIT, pdFALSE, pdFALSE, portMAX_DELAY);
+
+    /* xEventGroupWaitBits() returns the bits before the call returned, hence we can test which event actually
+     * happened. */
+    if(bits & WIFI_CONNECTED_BIT) {
+        ESP_LOGI(TAG, "connected to ap SSID:%s password:%s", WIFI_SSID, WIFI_PASS);
+    } else if(bits & WIFI_FAIL_BIT) {
+        ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s", WIFI_SSID, WIFI_PASS);
+    } else {
+        ESP_LOGE(TAG, "UNEXPECTED EVENT");
+    }
+
+    ESP_ERROR_CHECK(esp_event_handler_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler));
+    ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler));
+}

main/wifi.h

@@ -1,3 +1,3 @@
 #pragma once
 
-void wifi_init(void);
+void wifi_init(void);