test_minimal.cpp

/**
 * Minimal heap-stress test — WiFi + HTTP GET + JSON parse, NO display.
 *
 * Build:  pio run -e esp32-s3-radar --target upload
 * Then copy this file over src/main.cpp, or create a separate env.
 *
 * If this runs stable for 50+ iterations, the crash is caused by the
 * GDMA/display interaction with the PSRAM heap.  If it crashes here
 * too, the issue is more fundamental (power, module defect, etc.).
 */

#include <Arduino.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

#define WIFI_SSID     "Gramy Things"
#define WIFI_PASSWORD "thisismypassphraseblah"
#define HOST          "192.168.68.109"
#define PORT          8080
#define PATH          "/data/aircraft.json"

static int iteration = 0;

void setup() {
    Serial.begin(115200);
    delay(1000);
    Serial.println("\n=== Minimal heap-stress test ===");

    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    Serial.print("WiFi connecting");
    int retries = 0;
    while (WiFi.status() != WL_CONNECTED && retries < 60) {
        delay(500); Serial.print("."); retries++;
    }
    if (WiFi.status() != WL_CONNECTED) {
        Serial.println("\nWiFi FAILED"); return;
    }
    Serial.println("\nWiFi OK: " + WiFi.localIP().toString());
}

void loop() {
    /* Retry WiFi if it never connected in setup() */
    if (WiFi.status() != WL_CONNECTED) {
        Serial.print("WiFi reconnecting");
        WiFi.reconnect();
        int r = 0;
        while (WiFi.status() != WL_CONNECTED && r < 30) {
            delay(500); Serial.print("."); r++;
        }
        if (WiFi.status() == WL_CONNECTED) {
            Serial.println("\nWiFi reconnected: " + WiFi.localIP().toString());
        } else {
            Serial.println(" still down");
            delay(2000);
            return;
        }
    }

    iteration++;
    char url[128];
    snprintf(url, sizeof(url), "http://%s:%d%s", HOST, PORT, PATH);

    HTTPClient http;
    http.begin(url);
    http.setConnectTimeout(3000);
    http.setTimeout(5000);

    unsigned long t0 = millis();
    int code = http.GET();
    unsigned long dt = millis() - t0;

    if (code == 200) {
        String payload = http.getString();
        http.end();

        JsonDocument doc;
        DeserializationError err = deserializeJson(doc, payload);
        if (!err) {
            JsonArray arr = doc["aircraft"].as<JsonArray>();
            int count = arr ? arr.size() : 0;
            Serial.printf("[%4d] OK %d aircraft  %lu ms  heap=%u\n",
                          iteration, count, dt,
                          ESP.getFreeHeap());
        } else {
            Serial.printf("[%4d] JSON err: %s\n", iteration, err.c_str());
        }
    } else {
        http.end();
        Serial.printf("[%4d] HTTP %d (%lu ms)\n", iteration, code, dt);
    }

    delay(1000);
}