pridany zdrojak pre arduino a AGENTS.md

AGENTS.md

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+# Repository Guidelines
+
+## Project Structure & Module Organization
+
+This repository contains a small ESP8266/ESP32 Arduino project for monitoring water level with conductive electrodes.
+
+- `arduino/arduino.ino` contains the Arduino sketch and main application logic.
+- `README.md` gives the high-level project purpose.
+- `LICENSE` contains licensing information.
+- `.agents/` is reserved for agent/tooling metadata and should not be treated as firmware source.
+
+Keep Arduino source files inside the `arduino/` sketch directory so Arduino IDE can open and build the project correctly.
+
+## Build, Test, and Development Commands
+
+Use Arduino IDE or `arduino-cli` with the ESP8266 or ESP32 board package installed.
+
+Examples:
+
+```sh
+arduino-cli compile --fqbn esp8266:esp8266:nodemcuv2 arduino
+arduino-cli upload -p COM3 --fqbn esp8266:esp8266:nodemcuv2 arduino
+arduino-cli monitor -p COM3 -c baudrate=115200
+
+arduino-cli compile --fqbn esp32:esp32:esp32 arduino
+arduino-cli upload -p COM3 --fqbn esp32:esp32:esp32 arduino
+arduino-cli monitor -p COM3 -c baudrate=115200
+```
+
+- `compile` verifies the sketch builds for the selected board.
+- `upload` flashes the firmware to the connected board.
+- `monitor` opens the serial console used by debug output.
+
+Adjust `--fqbn` and `COM3` for the actual board and port.
+
+## Coding Style & Naming Conventions
+
+Write C++ compatible with Arduino IDE and the ESP8266/ESP32 cores. Use two-space indentation, braces on the same line, and descriptive names.
+
+- Constants: uppercase or clearly prefixed names, for example `PIN_LEVEL1`, `SLEEP_TIME_SEC`.
+- Structs and types: PascalCase, for example `WaterLevels`.
+- Functions: lower camelCase, for example `readLevels()` and `connectWifi()`.
+
+Prefer small functions with one responsibility. Keep hardware pins, URLs, timings, and debug flags as constants near the top of the sketch.
+
+## Hardware Notes
+
+For ESP8266 conductive level sensing, use external pull-down resistors from each `PIN_LEVEL1..4` input to `GND`. The common electrode is driven to positive voltage only during measurement.
+
+Avoid ESP8266 boot/strap pins for level inputs when possible, especially `GPIO0`, `GPIO2`, and `GPIO15`. Also avoid `GPIO1`/`GPIO3` unless intentionally sharing the serial port. Prefer ordinary GPIO pins such as `GPIO5`, `GPIO4`, `GPIO14`, `GPIO12`, or `GPIO13`, depending on the board and wiring.
+
+## Testing Guidelines
+
+There is no automated test framework in this repository. Validate changes by compiling the sketch and testing on hardware.
+
+Before committing firmware changes:
+
+- Compile for the target ESP8266 or ESP32 board.
+- Test `DEBUG == 1` for local level readings without Wi-Fi.
+- Test `DEBUG == 2` for repeated Wi-Fi POST requests.
+- Test `DEBUG == 0` for production sleep/wake behavior.
+
+## Commit & Pull Request Guidelines
+
+Current Git history is minimal and uses a simple message such as `Initial commit`. Keep future commits short, imperative, and specific, for example `Add WiFi timeout handling`.
+
+Pull requests should include:
+
+- A brief description of firmware behavior changed.
+- Board model and Arduino ESP8266/ESP32 core version used for testing.
+- Serial output or screenshots when debugging behavior changes.
+- Any required configuration changes, especially Wi-Fi, server URL, or pin mapping.
+
+## Security & Configuration Tips
+
+Avoid committing real Wi-Fi passwords or private server endpoints when possible. For shared changes, replace secrets with placeholders and document required local values.

arduino/arduino.ino

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+#if defined(ESP8266)
+#include <ESP8266WiFi.h>
+#include <ESP8266HTTPClient.h>
+#include <WiFiClientSecureBearSSL.h>
+#elif defined(ESP32)
+#include <WiFi.h>
+#include <HTTPClient.h>
+#include <WiFiClientSecure.h>
+#include <esp_sleep.h>
+#else
+#error "This sketch supports ESP8266 and ESP32 boards only."
+#endif
+
+const int PIN_COMMON_ELECTRODE = 13;  // GPIO13 / D7
+const int PIN_LEVEL1 = 5;             // GPIO5  / D1 - najnizsia hladina
+const int PIN_LEVEL2 = 4;             // GPIO4  / D2
+const int PIN_LEVEL3 = 14;            // GPIO14 / D5
+const int PIN_LEVEL4 = 12;            // GPIO12 / D6 - najvyssia hladina
+
+const int DEBUG = 1;
+
+const char WIFI_SSID[] = "TP-Link_DD1E";
+const char WIFI_PASS[] = "33784120";
+const unsigned long SLEEP_TIME_SEC = 1800;
+const char URL_LOG[] = "https://vihorlat.tpsoft.org/hladinac/server/log.php";
+
+const unsigned long WIFI_TIMEOUT_MS = 15000;
+const unsigned long MEASUREMENT_STABILIZE_MS = 50;
+
+struct WaterLevels {
+  int level1;
+  int level2;
+  int level3;
+  int level4;
+};
+
+void initPins();
+WaterLevels readLevels();
+void printLevels(const WaterLevels &levels);
+String buildPostBody(const WaterLevels &levels);
+bool connectWifi();
+bool sendLevelsToServer(const WaterLevels &levels);
+void enterDeepSleep();
+void setupLevelPin(int pin);
+void setCommonElectrodeOn();
+void setCommonElectrodeOff();
+int readLevelPin(int pin);
+
+void setup() {
+  Serial.begin(115200);
+  delay(200);
+  Serial.println("Hladinac v0.3 started.");
+
+  initPins();
+
+  if (DEBUG == 0) {
+    WaterLevels levels = readLevels();
+    printLevels(levels);
+
+    if (connectWifi()) {
+      sendLevelsToServer(levels);
+      WiFi.disconnect(true);
+      WiFi.mode(WIFI_OFF);
+    } else {
+      Serial.println("WiFi connection failed, skipping upload.");
+    }
+
+    enterDeepSleep();
+  } else if (DEBUG == 2) {
+    connectWifi();
+  }
+}
+
+void loop() {
+  if (DEBUG == 1) {
+    WaterLevels levels = readLevels();
+    printLevels(levels);
+    delay(1000);
+  } else if (DEBUG == 2) {
+    WaterLevels levels = readLevels();
+    printLevels(levels);
+
+    if (WiFi.status() != WL_CONNECTED) {
+      connectWifi();
+    }
+
+    sendLevelsToServer(levels);
+    delay(5000);
+  }
+}
+
+void initPins() {
+  pinMode(PIN_COMMON_ELECTRODE, OUTPUT);
+  setCommonElectrodeOff();
+
+  setupLevelPin(PIN_LEVEL1);
+  setupLevelPin(PIN_LEVEL2);
+  setupLevelPin(PIN_LEVEL3);
+  setupLevelPin(PIN_LEVEL4);
+}
+
+void setupLevelPin(int pin) {
+#if defined(ESP32)
+  pinMode(pin, INPUT_PULLDOWN);
+#else
+  // ESP8266 pouziva externe pull-down rezistory na GND.
+  pinMode(pin, INPUT);
+#endif
+}
+
+void setCommonElectrodeOn() {
+#if defined(ESP8266)
+  digitalWrite(PIN_COMMON_ELECTRODE, HIGH);
+#else
+  digitalWrite(PIN_COMMON_ELECTRODE, HIGH);
+#endif
+}
+
+void setCommonElectrodeOff() {
+#if defined(ESP8266)
+  digitalWrite(PIN_COMMON_ELECTRODE, LOW);
+#else
+  digitalWrite(PIN_COMMON_ELECTRODE, LOW);
+#endif
+}
+
+int readLevelPin(int pin) {
+#if defined(ESP8266)
+  return digitalRead(pin) == HIGH ? 1 : 0;
+#else
+  return digitalRead(pin) == HIGH ? 1 : 0;
+#endif
+}
+
+WaterLevels readLevels() {
+  WaterLevels levels;
+
+  // Spolocna elektroda je zapnuta iba pocas merania, aby sa znizila korozia.
+  setCommonElectrodeOn();
+  delay(MEASUREMENT_STABILIZE_MS);
+
+  levels.level1 = readLevelPin(PIN_LEVEL1);
+  levels.level2 = readLevelPin(PIN_LEVEL2);
+  levels.level3 = readLevelPin(PIN_LEVEL3);
+  levels.level4 = readLevelPin(PIN_LEVEL4);
+
+  setCommonElectrodeOff();
+
+  return levels;
+}
+
+void printLevels(const WaterLevels &levels) {
+  Serial.print("level1=");
+  Serial.print(levels.level1);
+  Serial.print(" level2=");
+  Serial.print(levels.level2);
+  Serial.print(" level3=");
+  Serial.print(levels.level3);
+  Serial.print(" level4=");
+  Serial.println(levels.level4);
+}
+
+String buildPostBody(const WaterLevels &levels) {
+  String body = "level1=" + String(levels.level1);
+  body += "&level2=" + String(levels.level2);
+  body += "&level3=" + String(levels.level3);
+  body += "&level4=" + String(levels.level4);
+  return body;
+}
+
+bool connectWifi() {
+  if (WiFi.status() == WL_CONNECTED) {
+    return true;
+  }
+
+  Serial.print("Connecting to WiFi");
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(WIFI_SSID, WIFI_PASS);
+
+  unsigned long startedAt = millis();
+  while (WiFi.status() != WL_CONNECTED && millis() - startedAt < WIFI_TIMEOUT_MS) {
+    delay(500);
+    Serial.print(".");
+  }
+
+  if (WiFi.status() == WL_CONNECTED) {
+    Serial.println();
+    Serial.print("WiFi connected, IP=");
+    Serial.println(WiFi.localIP());
+    return true;
+  }
+
+  Serial.println();
+  Serial.println("WiFi connection timeout.");
+  return false;
+}
+
+bool sendLevelsToServer(const WaterLevels &levels) {
+  if (WiFi.status() != WL_CONNECTED) {
+    Serial.println("Cannot send data, WiFi is not connected.");
+    return false;
+  }
+
+#if defined(ESP8266)
+  BearSSL::WiFiClientSecure client;
+#else
+  WiFiClientSecure client;
+#endif
+  client.setInsecure();
+
+  HTTPClient http;
+  if (!http.begin(client, URL_LOG)) {
+    Serial.println("HTTP begin failed.");
+    return false;
+  }
+
+  String body = buildPostBody(levels);
+  http.addHeader("Content-Type", "application/x-www-form-urlencoded");
+
+  int httpCode = http.POST(body);
+  if (httpCode > 0) {
+    Serial.print("POST sent, HTTP code=");
+    Serial.println(httpCode);
+  } else {
+    Serial.print("POST failed: ");
+    Serial.println(http.errorToString(httpCode));
+  }
+
+  http.end();
+  return httpCode > 0 && httpCode < 400;
+}
+
+void enterDeepSleep() {
+  Serial.print("Entering deep sleep for ");
+  Serial.print(SLEEP_TIME_SEC);
+  Serial.println(" seconds.");
+  Serial.flush();
+
+#if defined(ESP8266)
+  ESP.deepSleep((uint64_t)SLEEP_TIME_SEC * 1000000ULL);
+#else
+  esp_sleep_enable_timer_wakeup((uint64_t)SLEEP_TIME_SEC * 1000000ULL);
+  esp_deep_sleep_start();
+#endif
+}