Using Espressif IDE with C
Hi,
I've been attempting to modify the esp idf station example (examples\wifi\getting_started\station) to define 'EXAMPLE_ESP_WIFI_SSID' as a variable rather than as a preprocessor but have had no luck. I use powershell to compile and flash the board, and when it is not defined using "#define", it will not connect.
Defining the ssid though "const char* EXAMPLE_ESP_WIFI_SSID ="ssidname";", PowerShell shows "connect to the AP fail", but after retrying it correctly shows the SSID in the final line "Failed to connect to SSID: "ssidname", password: "password" ". Changing the ssid definition back to the original of "#define EXAMPLE_ESP_WIFI_SSID "ssidname" ", it connects right away. I have no clue why this happens.
The reason for having the ssid as a variable is because it will be retrieved from a HTTP POST form and extracted, then assigned to 'EXAMPLE_ESP_WIFI_SSID'. For now I am simply trying to move away from #define. Here is my code that only works with the ssid when it is assigned by #define:
- /* 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 <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.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 project configuration menu
- If you'd rather not, just change the below entries to strings with
- the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"*/
- //uncomment the line below to test the original #define from the example. make sure to comment out line 44.
- //#define EXAMPLE_ESP_WIFI_SSID "Telco5517"
- #define EXAMPLE_ESP_WIFI_PASS "bzs43cr"
- #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 two events:
- * - we are connected to 9 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 const char *TAG = "wifi station";
- static int s_retry_num = 0;
- //trying to define the ssid as a const char* instead of using #define
- const char* EXAMPLE_ESP_WIFI_SSID ="Telco5517";
- 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 < EXAMPLE_ESP_MAXIMUM_RETRY) {
- esp_wifi_connect();
- s_retry_num++;
- ESP_LOGI(TAG, "retry to connect to the AP");
- } else {
- xEventGroupSetBits(s_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(s_wifi_event_group, WIFI_CONNECTED_BIT);
- }
- }
- void wifi_init_sta(void)
- {
- s_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_event_handler_instance_t instance_any_id;
- esp_event_handler_instance_t instance_got_ip;
- ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
- ESP_EVENT_ANY_ID,
- &event_handler,
- NULL,
- &instance_any_id));
- ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,
- IP_EVENT_STA_GOT_IP,
- &event_handler,
- NULL,
- &instance_got_ip));
- wifi_config_t wifi_config = {
- .sta = {
- .ssid = {EXAMPLE_ESP_WIFI_SSID},
- .password = {EXAMPLE_ESP_WIFI_PASS},
- /* Setting a password implies station will connect to all security modes including WEP/WPA.
- * However these modes are deprecated and not advisable to be used. Incase your Access point
- * doesn't support WPA2, these mode can be enabled by commenting below line*/
- .threshold.authmode = WIFI_AUTH_WPA2_PSK,
- .pmf_cfg = {
- .capable = true,
- .required = false
- },
- },
- };
- ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );
- ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_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(s_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",
- EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
- } else if (bits & WIFI_FAIL_BIT) {
- ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s",
- EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
- } else {
- ESP_LOGE(TAG, "UNEXPECTED EVENT");
- }
- //The event will not be processed after unregister
- ESP_ERROR_CHECK(esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, instance_got_ip));
- ESP_ERROR_CHECK(esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id));
- vEventGroupDelete(s_wifi_event_group);
- }
- void app_main(void)
- {
- //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();
- }
Thanks,
wifibeginner