ESP32.md

#ESP32 This is a project that is attempting to port libcurl to an ESP32 environment. To use in your project, edit the component.mk and change the entry that points to my directory path of where we have downloaded the code to your directory path.

This is specified by the variable called CURL_DIR.

The project should be installed in an app template under a directory called components. A sample main.c application would be:

#include "freertos/FreeRTOS.h"
#include "esp_wifi.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_event_loop.h"
#include "nvs_flash.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "curl/curl.h"

#define SSID "guest"
#define PASSWORD "kolbanguest"

static char tag[] = "main";

static size_t writeData(void *buffer, size_t size, size_t nmemb, void *userp) {
	ESP_LOGI(tag, "writeData called: buffer=0x%lx, size=%d, nmemb=%d", (unsigned long)buffer, size, nmemb);
	ESP_LOGI(tag, "data>> %.*s", size*nmemb, (char *)buffer);
	return size * nmemb;
}

void testCurl(void *data) {
	CURL *handle;
	CURLcode res;

	// Create a curl handle
	handle = curl_easy_init();
	if (handle == NULL) {
		ESP_LOGI(tag, "Failed to create a curl handle");
		vTaskDelete(NULL);
		return;
	}

	ESP_LOGI(tag, "Created a curl handle ...");

  curl_easy_setopt(handle, CURLOPT_URL, "http://example.com");
  /* example.com is redirected, so we tell libcurl to follow redirection */
  curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1L);
  curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, writeData);
  /* Perform the request, res will get the return code */
  res = curl_easy_perform(handle);
  if (res != CURLE_OK) {
  	ESP_LOGI(tag, "curl_easy_perform failed: %s", curl_easy_strerror(res));
  } else {
  	ESP_LOGI(tag, "curl_easy_perform() completed without incident.");
  }
  curl_easy_cleanup(handle);
	vTaskDelete(NULL);
} // End of testCurl


esp_err_t event_handler(void *ctx, system_event_t *event)
{
	if (event->event_id == SYSTEM_EVENT_STA_GOT_IP) {
		ESP_LOGI(tag, "Got an IP ... ready to go!");
		xTaskCreatePinnedToCore(&testCurl, "testCurl", 10000, NULL, 5, NULL, 0);
		return ESP_OK;
	}
  return ESP_OK;
}

int app_main(void)
{
    nvs_flash_init();
    system_init();
    tcpip_adapter_init();
    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) );
    ESP_ERROR_CHECK( esp_wifi_set_storage(WIFI_STORAGE_RAM) );
    ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
    wifi_config_t sta_config = {
        .sta = {
            .ssid = SSID,
            .password = PASSWORD,
            .bssid_set = 0
        }
    };
    ESP_ERROR_CHECK( esp_wifi_set_config(WIFI_IF_STA, &sta_config) );
    ESP_ERROR_CHECK( esp_wifi_start() );
    ESP_ERROR_CHECK( esp_wifi_connect() );

    return 0;
}