Arduino Water Level sensor with battery check

water-level.ino

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <ArduinoJson.h>

#define trigPin  14 // d5
#define echoPin    12 // d6
#define SERVER_IP "10.0.0.55"

const int analogInPin = A0;

float vOUT = 0.0;
float vIN = 0.0;
float R2 = 7500.0;
float R1 = 30000.0;


// WiFi credentials.
const char* WIFI_SSID = "wifi-name";
const char* WIFI_PASS = "wifi-password";

WiFiClientSecure wifiClient;

void connect() {

  // Connect to Wifi.
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(WIFI_SSID);

  WiFi.begin(WIFI_SSID, WIFI_PASS);

  // WiFi fix: https://github.com/esp8266/Arduino/issues/2186
  WiFi.persistent(false);
  WiFi.mode(WIFI_OFF);
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASS);

  unsigned long wifiConnectStart = millis();

  while (WiFi.status() != WL_CONNECTED) {
    // Check to see if
    if (WiFi.status() == WL_CONNECT_FAILED) {
      Serial.println("Failed to connect to WiFi. Please verify credentials: ");
      delay(10000);
    }

    delay(500);
    Serial.println("...");
    // Only try for 5 seconds.
    if (millis() - wifiConnectStart > 15000) {
      Serial.println("Failed to connect to WiFi");
      return;
    }
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println();  
}

void sendData(int distance, float voltage) {
  Serial.print("Sending data to collector...");
  HTTPClient http;
 
  http.begin("http://" SERVER_IP  "/home/store");
  http.addHeader("Content-Type", "application/json");
  http.addHeader("Accept", "application/json");

  DynamicJsonDocument root(1024);
  root["distance"] = distance;
  root["voltage"] = voltage;

  String json;
  serializeJson(root, json);

  Serial.println(json);

  int httpCode = http.POST(json);

  if (httpCode > 0) {
    if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_CREATED) {
      
      Serial.println("Return code is ok");
      // Read response
      Serial.print(http.getString());

    } else {
      Serial.printf("Return code %d\n", httpCode);
      if (httpCode == 400) {
        Serial.println("Validation error: The device ID, access key, or access secret is not in the proper format.");
      }  else {
        Serial.println("Unknown response from API");
      }
    
      return;
    }
  } else {
   
    return;
  }

  http.end();
  
  }

// liczymy napiecie z wartosci
float calcVoltage(int value) {
   float vOUT;
   float vIN;
  
   vOUT = (value * 3.3) / 1024.0;
   vIN = vOUT / (R2 / (R1 + R2));
   return vIN;
}


// liczy odleglosc

int sonar() {
  long duration;
  int distance;
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);

  // Calculating the distance
  distance = duration * 0.034 / 2;
  return distance;
}

  
void setup(void) {
  pinMode(LED_BUILTIN, OUTPUT);

  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input

  digitalWrite(LED_BUILTIN, 0);
  
  Serial.begin(115200);
  //Serial.setTimeout(2000);
  Serial.println("");

 // while(!Serial) { }

  connect();

  int distance;
  int value;
  float voltage;

  distance = sonar();
  value = analogRead(analogInPin);
  voltage = calcVoltage(value);

  sendData(distance, voltage, value);
  
  Serial.println("sleep");
  
  ESP.deepSleep(30e6);

}

void loop() {
}