Add ESP8266 example

2026-10-26 12:14:56 +00:00 · 2020-12-27 01:29:42 +00:00
1 parent 7d1ef2ffe8
commit 71a22adc06
@@ -0,0 +1,86 @@
+#include <string.h>
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "freertos/task.h"
+#include "nvs_flash.h"
+
+#include "lwip/err.h"
+#include "lwip/sys.h"
+
+#include "mongoose.h"
+
+static EventGroupHandle_t s_wifi_event_group;
+
+/* The event group allows multiple bits for each event, but we only care about
+ * two events:
+ * - we are connected to the AP with an IP
+ * - we failed to connect after the maximum amount of retries */
+#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 < 3) {
+      esp_wifi_connect();
+      s_retry_num++;
+      LOG(LL_DEBUG, ("retry to connect to the AP"));
+    } else {
+      xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
+    }
+    LOG(LL_ERROR, ("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;
+    LOG(LL_INFO, ("got ip:%s", ip4addr_ntoa(&event->ip_info.ip)));
+    s_retry_num = 0;
+    xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+  }
+}
+
+void wifi_init(const char *ssid, const char *pass) {
+  s_wifi_event_group = xEventGroupCreate();
+  tcpip_adapter_init();
+  ESP_ERROR_CHECK(esp_event_loop_create_default());
+  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 c = {};
+  snprintf((char *) c.sta.ssid, sizeof(c.sta.ssid), "%s", ssid);
+  snprintf((char *) c.sta.password, sizeof(c.sta.password), "%s", pass);
+  if (pass != NULL && pass[0] != '\0') {
+    c.sta.threshold.authmode = WIFI_AUTH_WPA2_PSK;
+  }
+  ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+  ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &c));
+  ESP_ERROR_CHECK(esp_wifi_start());
+  EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,
+                                         WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
+                                         pdFALSE, pdFALSE, portMAX_DELAY);
+
+  if (bits & WIFI_CONNECTED_BIT) {
+    LOG(LL_INFO, ("connected to ap SSID:%s password:%s", ssid, pass));
+  } else if (bits & WIFI_FAIL_BIT) {
+    LOG(LL_ERROR, ("Failed to connect to SSID:%s, password:%s", ssid, pass));
+  } else {
+    LOG(LL_ERROR, ("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));
+  vEventGroupDelete(s_wifi_event_group);
+}