/*
* Application 1 — Setup, blink, web monitor
*
* What this scaffold gives you:
* - A WORKING dual-core ESP32 application.
* - Core 1 runs a blink_task that toggles an LED at 1 Hz with vTaskDelayUntil.
* - Core 0 runs an HTTP server that reports the LED state to a browser.
* - Wi-Fi is wired up for Wokwi's simulated "Wokwi-GUEST" access point.
*
* What you do:
* 1. Rename the task / log / page strings to fit your CHOSEN THEME.
* Search for YOURTHEME and replace every occurrence.
* 2. Customize the HTML in handle_root() to match your theme.
* 3. Optionally change LED_GPIO and BLINK_PERIOD_MS.
* 4. Run it, take a screenshot of the web page, drop both in your README.
*
* You should NOT need to add new tasks or change the architecture for App 1.
* That comes in App 2.
*
* ============================================================
* Theme: YOURTHEME <-- e.g., Avionics, Medical, Space, Industrial, Security
* ============================================================
*/
#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_http_server.h"
#include "esp_netif.h"
#include "nvs_flash.h"
/* ---------- Configuration ---------- */
#define LED_GPIO GPIO_NUM_2
#define BLINK_PERIOD_MS 1000 /* 1 Hz toggle */
#define HTTP_PORT 80
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASS "" /* Wokwi virtual AP is open */
#define CONFIG_LOG_DEFAULT_LEVEL_INFO 1
#define CONFIG_LOG_MAXIMUM_LEVEL 5
static const char *TAG = "app1";
/* Shared state: single bool, atomic read on Xtensa.
* (W6 will teach us why this is the only case where volatile-without-mutex is OK.) */
static volatile bool led_on = false;
static volatile uint32_t toggle_count = 0;
/* ---------- Blink task — runs on Core 1 (APP_CPU) ---------- */
static void blink_task(void *arg)
{
gpio_reset_pin(LED_GPIO);
gpio_set_direction(LED_GPIO, GPIO_MODE_OUTPUT);
/* vTaskDelayUntil is drift-free: we wake on a fixed schedule
* even if our work took a variable amount of time. */
TickType_t last_wake = xTaskGetTickCount();
const TickType_t period = pdMS_TO_TICKS(BLINK_PERIOD_MS);
for (;;) {
led_on = !led_on;
toggle_count++;
gpio_set_level(LED_GPIO, led_on);
ESP_LOGI(TAG, "[YOURTHEME] beacon = %s (toggle #%lu)",
led_on ? "ON" : "OFF", (unsigned long)toggle_count);
vTaskDelayUntil(&last_wake, period);
}
}
/* ---------- HTTP handler: live JSON state ---------- *
* Returns: {"on":true|false,"toggles":N}
* The page polls this 4x per second via fetch() — far faster and smoother
* than a meta-refresh full-page reload, and a realistic pattern for embedded
* dashboards. */
static esp_err_t handle_state(httpd_req_t *req)
{
char buf[64];
int n = snprintf(buf, sizeof(buf),
"{\"on\":%s,\"toggles\":%lu}",
led_on ? "true" : "false",
(unsigned long)toggle_count);
httpd_resp_set_type(req, "application/json");
httpd_resp_set_hdr(req, "Cache-Control", "no-store");
httpd_resp_send(req, buf, n);
return ESP_OK;
}
/* ---------- HTTP handler: root page (HTML shell only) ---------- *
* The HTML is served once. JavaScript polls /state at 4 Hz and updates the
* DOM in place — no full reload, no flicker, no Nyquist aliasing against
* the 1 Hz blink. */
static esp_err_t handle_root(httpd_req_t *req)
{
/* TODO: customize this HTML for your theme.
* Examples:
* - Avionics: "UAV-01 Beacon · status: ON"
* - Medical: "Heart-rate indicator · pulse: detected"
* - Space: "SAT-1 health beacon · t+00:42:17"
* - Industrial: "Ride-X dispatch · READY"
* - Security: "Enclave-A integrity · OK"
*/
static const char html[] =
"<!DOCTYPE html>"
"<html lang=\"en\"><head>"
"<meta charset=\"utf-8\">"
"<title>YOURTHEME monitor</title>"
"<style>"
" body { font-family: -apple-system, sans-serif; background: #FAFAF5; "
" color: #1A1A1A; padding: 2rem; }"
" h1 { color: #6B4F09; border-bottom: 3px solid #FFC904; "
" display: inline-block; padding-bottom: 4px; }"
" .state { font-size: 3em; font-weight: 700; margin: 1rem 0; "
" transition: color 120ms ease; }"
" .state.on { color: #1B6A2E; }"
" .state.off { color: #B81829; }"
" .meta { color: #6B4F09; font-variant-numeric: tabular-nums; }"
" .dot { display:inline-block; width: 0.6em; height: 0.6em; "
" border-radius: 50%; margin-right: 0.4em; "
" vertical-align: middle; transition: background 120ms ease; }"
" .dot.on { background: #1B6A2E; }"
" .dot.off { background: #B81829; }"
"</style></head>"
"<body>"
"<h1>YOURTHEME monitor</h1>"
"<p>Beacon state:</p>"
"<div id=\"state\" class=\"state off\">"
" <span id=\"dot\" class=\"dot off\"></span><span id=\"label\">--</span>"
"</div>"
"<p class=\"meta\">Toggles since boot: <span id=\"count\">0</span></p>"
"<p class=\"meta\">Polling at 4 Hz via <code>/state</code> JSON endpoint.</p>"
"<script>"
"async function poll(){"
" try{"
" const r = await fetch('/state',{cache:'no-store'});"
" const s = await r.json();"
" const cls = s.on ? 'on' : 'off';"
" document.getElementById('state').className = 'state ' + cls;"
" document.getElementById('dot').className = 'dot ' + cls;"
" document.getElementById('label').textContent = s.on ? 'ON' : 'OFF';"
" document.getElementById('count').textContent = s.toggles;"
" }catch(e){/* ignore transient network blips */}"
"}"
"setInterval(poll, 250);"
"poll();"
"</script>"
"</body></html>";
httpd_resp_set_type(req, "text/html");
httpd_resp_send(req, html, HTTPD_RESP_USE_STRLEN);
return ESP_OK;
}
static httpd_handle_t start_webserver(void)
{
httpd_config_t cfg = HTTPD_DEFAULT_CONFIG();
cfg.server_port = HTTP_PORT;
cfg.core_id = 0; /* networking on Core 0 */
cfg.task_priority = 5;
cfg.stack_size = 8192;
httpd_handle_t server = NULL;
if (httpd_start(&server, &cfg) == ESP_OK) {
httpd_uri_t root = {
.uri = "/",
.method = HTTP_GET,
.handler = handle_root,
.user_ctx = NULL
};
httpd_register_uri_handler(server, &root);
httpd_uri_t state = {
.uri = "/state",
.method = HTTP_GET,
.handler = handle_state,
.user_ctx = NULL
};
httpd_register_uri_handler(server, &state);
ESP_LOGI(TAG, "HTTP server started on port %d", HTTP_PORT);
} else {
ESP_LOGE(TAG, "HTTP server failed to start");
}
return server;
}
/* ---------- Wi-Fi event handler ---------- */
static void wifi_event_handler(void *arg, esp_event_base_t base, int32_t id, void *data)
{
if (base == WIFI_EVENT && id == WIFI_EVENT_STA_START) {
esp_wifi_connect();
} else if (base == WIFI_EVENT && id == WIFI_EVENT_STA_DISCONNECTED) {
ESP_LOGW(TAG, "Wi-Fi disconnected; reconnecting...");
esp_wifi_connect();
} else if (base == IP_EVENT && id == IP_EVENT_STA_GOT_IP) {
ip_event_got_ip_t *event = (ip_event_got_ip_t *)data;
ESP_LOGI(TAG, "Got IP: " IPSTR, IP2STR(&event->ip_info.ip));
start_webserver();
}
}
static void wifi_init_sta(void)
{
ESP_ERROR_CHECK(nvs_flash_init());
ESP_ERROR_CHECK(esp_netif_init());
ESP_ERROR_CHECK(esp_event_loop_create_default());
esp_netif_create_default_wifi_sta();
wifi_init_config_t init_cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK(esp_wifi_init(&init_cfg));
ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
&wifi_event_handler, NULL));
ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP,
&wifi_event_handler, NULL));
wifi_config_t wifi_cfg = {
.sta = {
.ssid = WIFI_SSID,
.password = WIFI_PASS,
.threshold.authmode = WIFI_AUTH_OPEN,
},
};
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_cfg));
ESP_ERROR_CHECK(esp_wifi_start());
}
/* ---------- app_main — kicks everything off ---------- */
void app_main(void)
{
esp_log_level_set(TAG, ESP_LOG_INFO);
ESP_LOGI(TAG, "==== App 1 [YOURTHEME] starting ====");
/* Start Wi-Fi + HTTP on Core 0 (PRO_CPU is networking by default in IDF) */
wifi_init_sta();
/* Pin the real-time blink task to Core 1 (APP_CPU). */
xTaskCreatePinnedToCore(
blink_task, /* function */
"blink", /* name (max 16 chars) */
2048, /* stack — 2048 words = 8 KB */
NULL, /* parameters */
5, /* priority */
NULL, /* task handle (we don't need it) */
APP_CPU_NUM /* Core 1 */
);
/* app_main returns; both cores keep running the tasks we created. */
}