feat: add ESP32 firmware with WiFi, API fetch, e-paper rendering, and captive portal

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-06 13:11:15 +02:00
parent a50ef96eb7
commit a52f164299
6 changed files with 892 additions and 0 deletions
@@ -0,0 +1,175 @@
+#include <Arduino.h>
+#include <WiFi.h>
+#include <HTTPClient.h>
+#include <ArduinoJson.h>
+
+// GxEPD2 for Waveshare 7.5" V2 (800x480, GxEPD2_750_T7)
+#include <GxEPD2_BW.h>
+#include <GxEPD2_750_T7.h>
+
+#include "config.h"
+#include "renderer.h"
+#include "captive_portal.h"
+
+// ── Pin mapping for Waveshare ESP32 Driver Board ──────────────────────────────
+#define EPD_CS   15
+#define EPD_DC   27
+#define EPD_RST  26
+#define EPD_BUSY 25
+
+// ── Display instance ──────────────────────────────────────────────────────────
+GxEPD2_BW<GxEPD2_750_T7, GxEPD2_750_T7::HEIGHT> display(
+    GxEPD2_750_T7(EPD_CS, EPD_DC, EPD_RST, EPD_BUSY)
+);
+
+// ── Deep sleep helper ─────────────────────────────────────────────────────────
+static void goDeepSleep(int seconds) {
+    Serial.printf("[Sleep] Entering deep sleep for %d seconds\n", seconds);
+    display.hibernate();
+    WiFi.disconnect(true);
+    WiFi.mode(WIFI_OFF);
+    esp_sleep_enable_timer_wakeup((uint64_t)seconds * 1000000ULL);
+    esp_deep_sleep_start();
+}
+
+// ── showError: white screen with centered error message ───────────────────────
+static void showError(const char* message) {
+    Serial.printf("[Error] %s\n", message);
+    display.setFullWindow();
+    display.firstPage();
+    do {
+        display.fillScreen(GxEPD_WHITE);
+        display.setTextColor(GxEPD_BLACK);
+        display.setTextSize(2);
+
+        // Print "FEHLER:" header
+        const char* header = "FEHLER:";
+        int headerW = 6 * 2 * strlen(header);
+        display.setCursor((display.width() - headerW) / 2, display.height() / 2 - 24);
+        display.print(header);
+
+        // Print message below
+        display.setTextSize(1);
+        int msgW = 6 * strlen(message);
+        display.setCursor((display.width() - msgW) / 2, display.height() / 2 + 4);
+        display.print(message);
+    } while (display.nextPage());
+}
+
+// ── setup ─────────────────────────────────────────────────────────────────────
+void setup() {
+    Serial.begin(115200);
+    Serial.println("[Boot] EPaper Display starting...");
+
+    // 1. Init display
+    display.init(115200);
+    display.setRotation(0);
+
+    // 2. Load config from NVS
+    Config config;
+    config.load();
+
+    // 3. If not configured → captive portal
+    if (!config.isConfigured()) {
+        Serial.println("[Boot] Not configured, starting captive portal");
+        display.setFullWindow();
+        display.firstPage();
+        do {
+            display.fillScreen(GxEPD_WHITE);
+            display.setTextColor(GxEPD_BLACK);
+            display.setTextSize(2);
+            const char* line1 = "Mit 'EPaper-Setup' WLAN verbinden";
+            const char* line2 = "und http://192.168.4.1 oeffnen";
+            int w1 = 6 * 2 * strlen(line1);
+            int w2 = 6 * 2 * strlen(line2);
+            display.setCursor((display.width() - w1) / 2, display.height() / 2 - 20);
+            display.print(line1);
+            display.setCursor((display.width() - w2) / 2, display.height() / 2 + 10);
+            display.print(line2);
+        } while (display.nextPage());
+
+        startCaptivePortal(config); // never returns
+    }
+
+    // 4. Connect to WiFi (30 attempts, 500 ms each)
+    Serial.printf("[WiFi] Connecting to %s\n", config.wifi_ssid.c_str());
+    WiFi.mode(WIFI_STA);
+    WiFi.begin(config.wifi_ssid.c_str(), config.wifi_password.c_str());
+
+    int attempts = 0;
+    while (WiFi.status() != WL_CONNECTED && attempts < 30) {
+        delay(500);
+        Serial.print(".");
+        ++attempts;
+    }
+    Serial.println();
+
+    if (WiFi.status() != WL_CONNECTED) {
+        showError("WiFi failed");
+        goDeepSleep(60);
+        return; // not reached
+    }
+    Serial.printf("[WiFi] Connected, IP: %s\n", WiFi.localIP().toString().c_str());
+
+    // 5. Build request URL
+    String url = config.api_url + "/api/display/" + config.display_id;
+    if (config.api_token.length() > 0) {
+        url += "?token=" + config.api_token;
+    }
+    Serial.printf("[HTTP] GET %s\n", url.c_str());
+
+    // 6. HTTP GET
+    HTTPClient http;
+    http.begin(url);
+    http.setTimeout(10000);
+    if (config.api_token.length() > 0) {
+        http.addHeader("Authorization", "Bearer " + config.api_token);
+    }
+
+    int httpCode = http.GET();
+    if (httpCode <= 0 || httpCode >= 400) {
+        Serial.printf("[HTTP] Error: %d\n", httpCode);
+        http.end();
+        showError(("HTTP " + String(httpCode)).c_str());
+        goDeepSleep(60);
+        return; // not reached
+    }
+
+    String payload = http.getString();
+    http.end();
+    Serial.printf("[HTTP] Payload length: %d\n", payload.length());
+
+    // 7. Parse JSON (ArduinoJson v7)
+    JsonDocument doc;
+    DeserializationError err = deserializeJson(doc, payload);
+    if (err) {
+        Serial.printf("[JSON] Parse error: %s\n", err.c_str());
+        showError(("JSON: " + String(err.c_str())).c_str());
+        goDeepSleep(60);
+        return; // not reached
+    }
+
+    // 8. Extract refresh_sec (prefer from JSON, fall back to config)
+    int refreshSec = doc["refresh_sec"] | config.refresh_sec;
+    if (refreshSec < 10) refreshSec = 60; // safety minimum
+
+    // 9. Render elements
+    JsonArray elements = doc["elements"].as<JsonArray>();
+
+    display.setFullWindow();
+    display.firstPage();
+    do {
+        display.fillScreen(GxEPD_WHITE);
+        renderElements(display, elements);
+    } while (display.nextPage());
+
+    Serial.println("[Render] Done");
+
+    // 10. Disconnect WiFi and deep sleep
+    goDeepSleep(refreshSec);
+}
+
+// ── loop ─────────────────────────────────────────────────────────────────────
+void loop() {
+    // Never reached: setup() ends in deep sleep
+}