* Use "example" in all example function & variable names, ie use i2c_example_xxx instead of i2c_xxx for example functions. Closes #198 https://github.com/espressif/esp-idf/issues/198 * Mark example functions, etc. static * Replace uses of "test" & "demo" with "example" * Split the UART example into two * Rename "main" example files to end with "_main.c" for disambiguation
180 lines
5.5 KiB
C
180 lines
5.5 KiB
C
/* HTTP GET Example using plain POSIX sockets
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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#include <string.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "freertos/event_groups.h"
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#include "esp_system.h"
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#include "esp_wifi.h"
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#include "esp_event_loop.h"
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#include "esp_log.h"
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#include "nvs_flash.h"
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#include "lwip/err.h"
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#include "lwip/sockets.h"
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#include "lwip/sys.h"
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#include "lwip/netdb.h"
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#include "lwip/dns.h"
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/* The examples use simple WiFi configuration that you can set via
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'make menuconfig'.
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If you'd rather not, just change the below entries to strings with
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the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
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*/
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#define EXAMPLE_WIFI_SSID CONFIG_WIFI_SSID
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#define EXAMPLE_WIFI_PASS CONFIG_WIFI_PASSWORD
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/* FreeRTOS event group to signal when we are connected & ready to make a request */
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static EventGroupHandle_t wifi_event_group;
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/* The event group allows multiple bits for each event,
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but we only care about one event - are we connected
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to the AP with an IP? */
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const int CONNECTED_BIT = BIT0;
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/* Constants that aren't configurable in menuconfig */
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#define WEB_SERVER "example.com"
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#define WEB_PORT 80
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#define WEB_URL "http://example.com/"
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static const char *TAG = "example";
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static const char *REQUEST = "GET " WEB_URL " HTTP/1.1\n"
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"Host: "WEB_SERVER"\n"
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"User-Agent: esp-idf/1.0 esp32\n"
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"\n";
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static esp_err_t event_handler(void *ctx, system_event_t *event)
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{
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switch(event->event_id) {
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case SYSTEM_EVENT_STA_START:
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esp_wifi_connect();
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break;
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case SYSTEM_EVENT_STA_GOT_IP:
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xEventGroupSetBits(wifi_event_group, CONNECTED_BIT);
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break;
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case SYSTEM_EVENT_STA_DISCONNECTED:
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/* This is a workaround as ESP32 WiFi libs don't currently
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auto-reassociate. */
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esp_wifi_connect();
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xEventGroupClearBits(wifi_event_group, CONNECTED_BIT);
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break;
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default:
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break;
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}
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return ESP_OK;
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}
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static void initialise_wifi(void)
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{
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tcpip_adapter_init();
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wifi_event_group = xEventGroupCreate();
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ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );
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wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
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ESP_ERROR_CHECK( esp_wifi_init(&cfg) );
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ESP_ERROR_CHECK( esp_wifi_set_storage(WIFI_STORAGE_RAM) );
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wifi_config_t wifi_config = {
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.sta = {
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.ssid = EXAMPLE_WIFI_SSID,
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.password = EXAMPLE_WIFI_PASS,
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},
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};
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ESP_LOGI(TAG, "Setting WiFi configuration SSID %s...", wifi_config.sta.ssid);
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ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
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ESP_ERROR_CHECK( esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
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ESP_ERROR_CHECK( esp_wifi_start() );
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}
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static void http_get_task(void *pvParameters)
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{
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const struct addrinfo hints = {
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.ai_family = AF_INET,
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.ai_socktype = SOCK_STREAM,
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};
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struct addrinfo *res;
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struct in_addr *addr;
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int s, r;
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char recv_buf[64];
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while(1) {
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/* Wait for the callback to set the CONNECTED_BIT in the
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event group.
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*/
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xEventGroupWaitBits(wifi_event_group, CONNECTED_BIT,
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false, true, portMAX_DELAY);
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ESP_LOGI(TAG, "Connected to AP");
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int err = getaddrinfo(WEB_SERVER, "80", &hints, &res);
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if(err != 0 || res == NULL) {
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ESP_LOGE(TAG, "DNS lookup failed err=%d res=%p", err, res);
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vTaskDelay(1000 / portTICK_PERIOD_MS);
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continue;
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}
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/* Code to print the resolved IP.
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Note: inet_ntoa is non-reentrant, look at ipaddr_ntoa_r for "real" code */
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addr = &((struct sockaddr_in *)res->ai_addr)->sin_addr;
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ESP_LOGI(TAG, "DNS lookup succeeded. IP=%s", inet_ntoa(*addr));
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s = socket(res->ai_family, res->ai_socktype, 0);
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if(s < 0) {
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ESP_LOGE(TAG, "... Failed to allocate socket.");
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freeaddrinfo(res);
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vTaskDelay(1000 / portTICK_PERIOD_MS);
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continue;
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}
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ESP_LOGI(TAG, "... allocated socket\r\n");
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if(connect(s, res->ai_addr, res->ai_addrlen) != 0) {
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ESP_LOGE(TAG, "... socket connect failed errno=%d", errno);
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close(s);
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freeaddrinfo(res);
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vTaskDelay(4000 / portTICK_PERIOD_MS);
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continue;
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}
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ESP_LOGI(TAG, "... connected");
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freeaddrinfo(res);
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if (write(s, REQUEST, strlen(REQUEST)) < 0) {
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ESP_LOGE(TAG, "... socket send failed");
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close(s);
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vTaskDelay(4000 / portTICK_PERIOD_MS);
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continue;
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}
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ESP_LOGI(TAG, "... socket send success");
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/* Read HTTP response */
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do {
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bzero(recv_buf, sizeof(recv_buf));
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r = read(s, recv_buf, sizeof(recv_buf)-1);
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for(int i = 0; i < r; i++) {
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putchar(recv_buf[i]);
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}
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} while(r > 0);
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ESP_LOGI(TAG, "... done reading from socket. Last read return=%d errno=%d\r\n", r, errno);
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close(s);
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for(int countdown = 10; countdown >= 0; countdown--) {
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ESP_LOGI(TAG, "%d... ", countdown);
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vTaskDelay(1000 / portTICK_PERIOD_MS);
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}
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ESP_LOGI(TAG, "Starting again!");
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}
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}
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void app_main()
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{
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ESP_ERROR_CHECK( nvs_flash_init() );
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initialise_wifi();
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xTaskCreate(&http_get_task, "http_get_task", 2048, NULL, 5, NULL);
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}
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