Finish captive portal: NVS config, POST handler, STA connect, AP identity

Splits provisioning (softAP + captive portal + NVS-backed config) into wifi_provisioning.c and home-network connection into frame_client.c. /save_config now parses the form body and persists it to NVS; on boot the device goes straight to STA mode if a config exists, retrying a few times before falling back to provisioning if the home network is unreachable. The provisioning AP is now always named ESPRESSO with a random per-device password (generated once, persisted in NVS) instead of a fixed Kconfig value, drawn from a charset that avoids visually ambiguous characters since it'll be read off the e-ink panel and possibly typed by hand.
2026-07-18 10:48:52 -04:00
parent cb50c99c98
commit de449d5973
7 changed files with 610 additions and 189 deletions
@@ -0,0 +1,114 @@
+#include <string.h>
+
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_wifi.h"
+#include "esp_netif.h"
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/event_groups.h"
+
+#include "frame_client.h"
+
+static const char *TAG = "frame_client";
+
+#define STA_CONNECTED_BIT BIT0
+#define STA_FAILED_BIT BIT1
+
+static EventGroupHandle_t s_sta_event_group;
+
+/* wifi_sta_config_t's ssid/password fields are fixed-size byte arrays, not
+ * necessarily null-terminated (a full 32-char SSID fills the field exactly).
+ * snprintf() flags that as a possible truncation at -Werror, so copy by
+ * hand instead. */
+static void copy_wifi_field(uint8_t *dst, size_t dst_size, const char *src)
+{
+    size_t len = strnlen(src, dst_size);
+    memcpy(dst, src, len);
+    if (len < dst_size) {
+        dst[len] = '\0';
+    }
+}
+
+static void sta_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) {
+        ESP_LOGW(TAG, "Disconnected from home WiFi");
+        xEventGroupSetBits(s_sta_event_group, STA_FAILED_BIT);
+    } 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));
+        xEventGroupSetBits(s_sta_event_group, STA_CONNECTED_BIT);
+    }
+}
+
+esp_err_t frame_wifi_connect_sta(const frame_config_t *cfg)
+{
+    s_sta_event_group = xEventGroupCreate();
+
+    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_event_handler_instance_t wifi_handler;
+    esp_event_handler_instance_t ip_handler;
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &sta_event_handler, NULL, &wifi_handler));
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &sta_event_handler, NULL, &ip_handler));
+
+    wifi_config_t wifi_config = {0};
+    copy_wifi_field(wifi_config.sta.ssid, sizeof(wifi_config.sta.ssid), cfg->sta_ssid);
+    copy_wifi_field(wifi_config.sta.password, sizeof(wifi_config.sta.password), cfg->sta_password);
+
+    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_err_t result = ESP_FAIL;
+    for (int attempt = 1; attempt <= CONFIG_FRAME_STA_CONNECT_MAX_RETRIES; attempt++) {
+        ESP_LOGI(TAG, "Connecting to '%s' (attempt %d/%d)", cfg->sta_ssid, attempt,
+                 CONFIG_FRAME_STA_CONNECT_MAX_RETRIES);
+
+        xEventGroupClearBits(s_sta_event_group, STA_CONNECTED_BIT | STA_FAILED_BIT);
+        esp_wifi_connect();
+
+        EventBits_t bits = xEventGroupWaitBits(s_sta_event_group, STA_CONNECTED_BIT | STA_FAILED_BIT,
+                                                pdTRUE, pdFALSE,
+                                                pdMS_TO_TICKS(CONFIG_FRAME_STA_CONNECT_TIMEOUT_MS));
+
+        if (bits & STA_CONNECTED_BIT) {
+            result = ESP_OK;
+            break;
+        }
+        ESP_LOGW(TAG, "Attempt %d/%d failed", attempt, CONFIG_FRAME_STA_CONNECT_MAX_RETRIES);
+    }
+
+    esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, wifi_handler);
+    esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, ip_handler);
+    vEventGroupDelete(s_sta_event_group);
+    s_sta_event_group = NULL;
+
+    if (result != ESP_OK) {
+        esp_wifi_stop();
+    }
+
+    return result;
+}
+
+void frame_client_run(const frame_config_t *cfg)
+{
+    /* TODO(step 6): HTTP fetch from cfg->toolsserver -> epd_write_stream ->
+     * epd_refresh -> esp_deep_sleep. Idling here for now so the device
+     * stays observable over serial while STA connectivity is verified. */
+    ESP_LOGI(TAG, "Connected to home WiFi. toolsserver='%s' (fetch/display cycle not yet implemented)",
+             cfg->toolsserver);
+
+    while (1) {
+        ESP_LOGI(TAG, "heartbeat: still connected");
+        vTaskDelay(pdMS_TO_TICKS(60000));
+    }
+}