I came across this code on the internet. It was using MQTT, nodemcu to achieve water level monitor.
The hardware setup is as above and code is as found below
/********************* ADD FOLLOWING LIBRARIES TO ARDUINO IDE ****************************/
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>
#include <ArduinoJson.h>
/******************* ADD YOUR WIFI and MQTT INFORMATION HERE ****************************/
#define wifi_ssid "your wifi ssid"
#define wifi_password "your wifi password"
#define mqtt_server "your mqtt server IP"
#define mqtt_user "your mqtt user name"
#define mqtt_password "your mqtt password"
#define mqtt_port 1883
#define state_topic "watertank/level"
/**************************** FOR OVER THE AIR(OTA) UPDATES *****************************/
#define SENSORNAME "Watertank NodeMCU"
int OTAport = 8266;
/***************************** PIN DEFINATIONS *****************************************/
const int greenLED = D0;
const int redLED = D1;
const int quarter = D7;
const int half = D6;
const int threeFourth = D5;
const int full = D2;
int flag0=0;
int flag1=0;
int flag2=0;
int flag3=0;
int flag4=0;
int flag5=0;
String levelStatus;
char message_buff[100];
int calibrationTime = 0;
const int BUFFER_SIZE = 300;
#define MQTT_MAX_PACKET_SIZE 512
WiFiClient espClient;
PubSubClient client(espClient);
/********************************** START SETUP*****************************************/
void setup() {
//Serial.begin(115200); //Start serial monitor for debugging...
pinMode(greenLED, OUTPUT);
pinMode(redLED, OUTPUT);
pinMode(quarter, INPUT_PULLUP);
pinMode(half, INPUT_PULLUP);
pinMode(threeFourth, INPUT_PULLUP);
pinMode(full, INPUT_PULLUP);
ArduinoOTA.setPort(OTAport);
ArduinoOTA.setHostname(SENSORNAME);
delay(10);
Serial.println("Starting Node named " + String(SENSORNAME));
setup_wifi();
client.setServer(mqtt_server, mqtt_port);
ArduinoOTA.onStart([]() {
Serial.println("Starting");
});
ArduinoOTA.onEnd([]() {
Serial.println("\nEnd");
});
ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
});
ArduinoOTA.onError([](ota_error_t error) {
Serial.printf("Error[%u]: ", error);
if (error == OTA_AUTH_ERROR) Serial.println("Auth Failed");
else if (error == OTA_BEGIN_ERROR) Serial.println("Begin Failed");
else if (error == OTA_CONNECT_ERROR) Serial.println("Connect Failed");
else if (error == OTA_RECEIVE_ERROR) Serial.println("Receive Failed");
else if (error == OTA_END_ERROR) Serial.println("End Failed");
});
ArduinoOTA.begin();
Serial.println("Ready");
Serial.print("IPess: ");
Serial.println(WiFi.localIP());
reconnect();
}
/********************************** SETUP WIFI *****************************************/
void setup_wifi() {
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(wifi_ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(wifi_ssid, wifi_password);
while (WiFi.status() != WL_CONNECTED) {
digitalWrite(greenLED, HIGH);
digitalWrite(redLED, LOW);
delay(500);
digitalWrite(greenLED, LOW);
digitalWrite(redLED, HIGH);
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
digitalWrite(greenLED, LOW);
digitalWrite(redLED, LOW);
}
/********************************** START SEND STATE*****************************************/
void sendState() {
StaticJsonBuffer<BUFFER_SIZE> jsonBuffer;
JsonObject& root = jsonBuffer.createObject();
root["waterlevel"] = (String)levelStatus;
char buffer[root.measureLength() + 1];
root.printTo(buffer, sizeof(buffer));
Serial.println(buffer);
client.publish(state_topic, buffer, true);
}
/********************************** START RECONNECT*****************************************/
void reconnect() {
// Loop until we reconnect
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect(SENSORNAME, mqtt_user, mqtt_password)) {
Serial.println("connected");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void loop() {
ArduinoOTA.handle();
if (!client.connected()) {
flag0=0; flag1=0; flag2=0; flag3=0; flag4=0; flag5=0;
digitalWrite(redLED, LOW);
digitalWrite(greenLED, LOW);
reconnect();
}
client.loop();
if ((digitalRead(quarter)==HIGH) && (digitalRead(half)==HIGH) && (digitalRead(threeFourth)==HIGH) && (digitalRead(full)==HIGH)){ //if water level is below 25%
if (flag0 == 0) {
Serial.println("Tank is empty.....");
digitalWrite(redLED, HIGH);
digitalWrite(greenLED, LOW);
levelStatus = "Empty";
sendState();
flag0=1; flag1=0; flag2=0; flag3=0; flag4=0; flag5=0;
}}
else if ((digitalRead(quarter)==LOW) && (digitalRead(half)==HIGH) && (digitalRead(threeFourth)==HIGH) && (digitalRead(full)==HIGH)){ //if water level is above 25%
if (flag1 == 0) {
digitalWrite(redLED, HIGH);
digitalWrite(greenLED, LOW);
Serial.println("Tank is quarter.....");
levelStatus = "25% Filled";
sendState();
flag0=0; flag1=1; flag2=0; flag3=0; flag4=0; flag5=0;
}}
else if ((digitalRead(quarter)==LOW) && (digitalRead(half)==LOW) && (digitalRead(threeFourth)==HIGH) && (digitalRead(full)==HIGH)){ //if water level is above 50%
if (flag2 == 0) {
digitalWrite(redLED, HIGH);
delay(100);
digitalWrite(greenLED, HIGH);
Serial.println("Tank is 50%.....");
levelStatus = "Half Filled";
sendState();
flag0=0; flag1=0; flag2=1; flag3=0; flag4=0; flag5=0;
}}
else if ((digitalRead(quarter)==LOW) && (digitalRead(half)==LOW) && (digitalRead(threeFourth)==LOW) && (digitalRead(full)==HIGH)){ //if water level is above 75%
if (flag3 == 0) {
digitalWrite(redLED, LOW);
digitalWrite(greenLED, HIGH);
Serial.println("Tank is 75%.....");
levelStatus = "75% Filled";
sendState();
flag0=0; flag1=0; flag2=0; flag3=1; flag4=0; flag5=0;
}}
else if ((digitalRead(quarter)==LOW) && (digitalRead(half)==LOW) && (digitalRead(threeFourth)==LOW) && (digitalRead(full)==LOW)){ //if water tank is Full
if (flag4 == 0) {
digitalWrite(redLED, LOW);
digitalWrite(greenLED, LOW);
Serial.println("Tank is full.....");
levelStatus = "Full";
sendState();
//client.publish(tankState, "Full"); //publish the current state to MQTT
flag0=0; flag1=0; flag2=0; flag3=0; flag4=1; flag5=0;
}}
else { Serial.println("Error.....");
if (flag5 == 0) {
levelStatus = "Sensor Cable Error...";
sendState();
flag0=0; flag1=0; flag2=0; flag3=0; flag4=0; flag5=1; }
else {
digitalWrite(greenLED, HIGH);
digitalWrite(redLED, LOW);
delay(1000);
digitalWrite(greenLED, LOW);
digitalWrite(redLED, HIGH);
delay(1000);
digitalWrite(greenLED, LOW);
digitalWrite(redLED, LOW);
}} delay(2000);
}
