ESP32 Forum

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#include "station.h"
#include "Arduino.h"
#include "WiFi.h"
#include <HTTPClient.h>

extern "C" void wifi_init_sta();

static void activate_wifi()
{
  //Initialize NVS
  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);

  ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");
  wifi_init_sta();
}

static void http_get_task(void *pvParameters)
{
    while(1) {
      // xEventGroupWaitBits(s_wifi_event_group, WIFI_CONNECTED_BIT,
      //                     false, true, portMAX_DELAY);
      //
      // ESP_LOGI(TAG, "Connected to AP");
      if(WiFi.status() == WL_CONNECTED){   //Check WiFi connection status

          HTTPClient http;

          http.begin("http://jsonplaceholder.typicode.com/posts");  //Specify destination for HTTP request
          http.addHeader("Content-Type", "text/plain");             //Specify content-type header

          int httpResponseCode = http.POST("POSTING from ESP32");   //Send the actual POST request

          if(httpResponseCode>0){

           String response = http.getString();                       //Get the response to the request

           Serial.println(httpResponseCode);   //Print return code
           Serial.println(response);           //Print request answer

          }else{

           Serial.print("Error on sending POST: ");
           Serial.println(httpResponseCode);

          }

          http.end();  //Free resources

        }else{
           Serial.println("Error in WiFi connection");
        }
    }
}

void serialSetup() {
    Serial.begin(115200);
    Serial.println("Serial.begin(115200) DONE");
    delay(10);
    Serial.println("serialSetup done");
}

extern "C" void app_main()
{
    initArduino();
    serialSetup();
    activate_wifi();
    xTaskCreate(&http_get_task, "http_get_task", 44096, NULL, 5, NULL);
}

Code: Select all

/* WiFi station Example
   This example code is in the Public Domain (or CC0 licensed, at your option.)
   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#pragma once
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"

#include "lwip/err.h"
#include "lwip/sys.h"

/* The examples use WiFi configuration that you can set via 'make menuconfig'.
   If you'd rather not, just change the below entries to strings with
   the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
*/
#define EXAMPLE_ESP_WIFI_SSID      CONFIG_ESP_WIFI_SSID
#define EXAMPLE_ESP_WIFI_PASS      CONFIG_ESP_WIFI_PASSWORD

#define EXAMPLE_ESP_MAXIMUM_RETRY  CONFIG_ESP_MAXIMUM_RETRY

/* FreeRTOS event group to signal when we are connected*/
static EventGroupHandle_t s_wifi_event_group;

/* The event group allows multiple bits for each event, but we only care about one event
 * - are we connected to the AP with an IP? */
const int WIFI_CONNECTED_BIT = BIT0;

static const char *TAG = "wifi station";

static int s_retry_num = 0;

static esp_err_t event_handler(void *ctx, system_event_t *event);

Code: Select all

/* WiFi station Example
   This example code is in the Public Domain (or CC0 licensed, at your option.)
   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#include "station.h"

static esp_err_t event_handler(void *ctx, system_event_t *event)
{
    switch(event->event_id) {
    case SYSTEM_EVENT_STA_START:
        esp_wifi_connect();
        break;
    case SYSTEM_EVENT_STA_GOT_IP:
        ESP_LOGI(TAG, "got ip:%s",
                 ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
        s_retry_num = 0;
        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
        break;
    case SYSTEM_EVENT_STA_DISCONNECTED:
        {
            if (s_retry_num < EXAMPLE_ESP_MAXIMUM_RETRY) {
                esp_wifi_connect();
                xEventGroupClearBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
                s_retry_num++;
                ESP_LOGI(TAG,"retry to connect to the AP");
            }
            ESP_LOGI(TAG,"connect to the AP fail\n");
            break;
        }
    default:
        break;
    }
    return ESP_OK;
}

void wifi_init_sta()
{
    tcpip_adapter_init();
    s_wifi_event_group = xEventGroupCreate();

    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL) );

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
    wifi_config_t wifi_config = {
        .sta = {
            .ssid = EXAMPLE_ESP_WIFI_SSID,
            .password = EXAMPLE_ESP_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.");
    ESP_LOGI(TAG, "connect to ap SSID:%s password:%s",
             EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
}