There is a total of 7 transistors and they will be sensing the water level. NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); float TankHeight, WaterLevelMAX, GapbwSonar, SonarReading, ActualReading, Temp; lcd.begin(20, 4); // set up the LCD's number of columns and rows: pinMode(MOTORPIN, OUTPUT);// Relay pin as output pin, digitalWrite(MOTORPIN, LOW); //Turn off the relay, pinMode(BUZZER, OUTPUT);// Buzzer pin as output pin, digitalWrite(BUZZER, LOW); //Turn off the Buzzer, WaterLevelMAX=0.9*TankHeight; // 10CM GAP BETWEEN MAX WATER LEVEL TO SONAR FIX. I tend to make life easier by making circuits and designs to automate things around me. Used advanced embedded technology, 7.29921259098 7.29921259098 5.09842519165 in. All the householders are storing the water in overhead tanks by using the motor pumps. We could go with a micro controller like Atmega 328p (used on the Arduino board) that has multi-channel ADC (and hence multiple Analog pins) or use a multiplexer/demultiplexer with the Node MCU board. This problem can be tackled in an electronic way. 
When the P2 probe was dropped into the mug with water, the green LED lit up validating this design. Valve to Reduce Steam Deck Supply Chain Issues, Intel Arc A770M Tested in 3DMark Time Spy, Performance Equal to the RTX 3070M, Apple Claims That Supply Issues Are Severely Hurting Mac Sales, AMDs Upcoming Zen 4 Based 7600X Tested, Crushes the i9-12900K, AMDs Rembrandt Based APU Tested, Features the Zen3+ Architecture. Get an alert via email when the water level reaches a critical threshold. This was a bit puzzling at first and after ruling out possibilities like soldering issues etc he was able to get to the root cause of the issue. This requires a person to check the water levels in the overhead tank and the sump at periodic intervals, turn on the motor when the water level drops down in the overhead tank and turn off the motor once the tank is filled. The HC-SR04 ultrasonic module is a module that can provide non-contact measurement within the range of 2cm to 400cm with ranging accuracy that can reach 3mm. If Water level above 100% then Pump will stopped. During testing, the digital input pins always read logic level LOW (0) even when the probes were immersed in water. This project monitors the water level and emails alerts. Fix that loop of wire with nuts and bolts in that PVC pipe and afterward add a common wire to the casing. . There is a current limiting resistor involved between transistor and LED and it prevents higher voltage to destroy the LED. This process can be problematic during monsoon season. This would be too low for the digital pin to give a logic level HIGH and that explains the failure of the older design in Trivandrum.
The components used in this project are easily available in the market. I considered alternate methodologies for detecting water level, but they had practical issues and hence I had to go with the carbon probe with voltage detection. One of the major problems faced by most of the countries is the issue of water scarcity in the world. Digital pin D1 is set to output mode while pins D2, D5, D6, D7, D8 are set to input mode. Project tutorial by Pranav Kundaikar and Vinayak Shantaram Joshi. All the commercial products available on Amazon use a similar approach to detect water level. Water level detection (or liquid level detection) is not a new problem and there are a number of commercial off-the-shelf products available in the market. This ADC can map the input voltage to an integer between 0 to 1023. We discussed about having a smart sensor hooked to a programmable switch that can turn on/off the motor. As a first step I built a prototype to validate this idea with an Arduino Nano. However, this setup requires running electric wires from the controller located in the ground floor to the probes hanging in the water tank on the terrace. This may not be ideal depending on the house/apartment. Then cut the plastic board for the Power Switch. It works very long life. Choose that place which is out of reach of children and from where you can easily turn ON and OFF the switch. If P4 is hung close to the top of the tank, the motor can be turned off once non-zero voltage is detected at P4. Adding salt to the water resolved the problem. Most of these products use carbon/steel probes. Among all the components the most important components are Transistors BC 547. Free shipping on orders above Rs.499/- Dismiss, PiBOX India Raspberry Pi 4 8GB Jump Start8 Combo kit 4813W with Pi4 8GB, Pi4 Black case,16GB Noobs Card, BIS 3 amps Charger, Copper Heatsink, HDMI Cable, Ethernet Cable and Adapters 2022 Model, REES52 Ultrasonic Range Finder Module Sensor Distance Measuring Transducer New, PiBOX India Raspberry Pi 4 4GB Easy Cool 4 Combo kit 4413W with Pi4 4GB, Pi4 Fan case, Dual Speed Fan,16GB Noobs Card, BIS 3 Amps Charger, 3 Piece Heatsink, HDMI Cable and Accessories, Erratum Solutions FPM10A Fingerprint Reader-Sensor Module Arduino Locks. Presently for the establishment of the gadget, we should locate a reasonable spot for a clear view of LED lights. We need to put the circuit in a small box and make holes in it appropriately so that LEDs may come out of the box easily. In this example configuration, electricity is passed into water through probe P1 and voltage is measured at probes P2, P3 and P4. Level Monitoring and Control with dry Pump run protection using Ultrasonic Sensor and Android Application via bluetooth HC-05. It is this value that will enable us calibrate the tank.Here introduced a push button, this is used to measure the Tank height at the time of installation of this Circuit.
I decided to build a microcontroller based solution that detects and transmits the water level to a cloud hosted database. Firmly fix the rod inside the tank and make sure that the rod (PVC pipe) touches the bottom of the tank. Ive tackled it in a slightly different way sometime back, using an ultrasonic sensor. Level Monitoring and Control with dry Pump run protection using Ultrasonic Sensor and Android Applcation via bluetooth HC-05.
The CD74HC4067 multiplexer has 4 data pins (S0, S1, S2, S3) that can be set to HIGH or LOW and the combination of the HIGH/LOW values determine the channel (C0 through C15) that is operational. I looked at a few products available on Amazon that detect water level and turn off the motor/pump (there are different variants that work with single phase motors and 3 phase motors). Awesome project. We will screw the two L hooks to the device and fix it into the wall and afterward take A/C 220V from any socket and give it to the board. if Pump running and Sump tank empty then Pump will stopped. I choose ESP8266 based Node MCU microcontroller board.
As we are using 5 digital pins in input mode, this circuit requires 5 pull down resistors. My colleague built a prototype with the Mk1 design and tested it at his home (in Trivandrum, Kerala). This unit will display the Water Level in percentage, Pump status, tank Height and Sump tank status.. MAX_DISTANCE 500 // Maximum sensor distance is rated at 400-500cm. Gap between Ultrasonic and Max water level adjusted in Arduino code. Buzzer, this is used to notify when the sump tank is empty. I decided to give this a shot and see if I can come up with a solution. After analyzing the circuit we came to know that five supply lines need to be taken out from the main circuit board to the sensor. These days everyone has an overhead tank at their homes. Keep rocking. Easy to install.
How To Detect Rainfall Using Rain Sensor? When the water is stored in the tank, no one can identify the level of water and also, no one can know when the water tank will be filled. #define TRIGGER_PIN 6 // Arduino pin tied to trigger pin on the ultrasonic sensor. Take a PCB board and solder the LEDs on it according to the levels defined above.
Another problem Ive observed is with the diaphragm getting water vapour settled on it causing accuracy problems. // put your main code here, to run repeatedly: Water Quality Monitoring and Notification System, Christmas Tree Water Level via Cayenne and MKR1000. On getting to the surface of the water, the wave is echoed back to the sensor and the arduino reads the echo pin to determine time spent between triggering and receiving of the echo. A few months back I had a discussion with a colleague about the need for a water level sensor for his house. Subsequently the Mk2 prototype was tested in Trivandrum and was able to detect water level without the need for mixing salt. This can further used if you wish to replace the water tank with a new one. #define MAX_DISTANCE 500 // Maximum sensor distance is rated at 400-500cm. To resolve this type of problems by using implementation of water level monitors and control systems using wireless technology which will transmit the information to the smart phone and indicate the level of water in the overhead tanks. A single page application built with Google Charts helps users visualise the water level. Tank water level monitored in Android Mobile using app. The Node MCU board can also be stripped down further and could be powered by a battery, but we did not venture in that direction as power supply was available on the terrace.
The Arduino Nano was programmed to light the green on-board LED when the D4 pin reads logic level HIGH (1) and show the red LED when the D4 pin reads logic level LOW (0). How To Detect Water Level In The Overhead Tank Installed On Roof? Yet another very useful utility for day to day life. It observes the level of water and provides the information to the registered users through wireless. The output pin would send 5V DC voltage into the probe and water and the input pin would read the voltage and would give back logic level HIGH (1) if the voltage is above (2.6V) a threshold value. Project tutorial by Robodia Technology Solutions. This idea can be extended further to replenish the sump if we add water level sensors to the sump as well. percentage=(ActualReading/WaterLevelMAX*100); else if(percentage>20 && percentage<=100), if(percentage>20 && percentage<=100 && flag ==1), else if(percentage>20 && percentage<=100 && flag ==0), https://drive.google.com/file/d/11egiPu2fzW4Sn2ypX6yYpG9r5-iuY-TP/view?usp=sharing, https://drive.google.com/file/d/1_5t3tVkQNHQk60k0gRRFQR1lUCjvaC1z/view?usp=sharing. Now, that weve collected all the components lets assemble them and design the circuit. The scarcity is mainly due to the wastage of the water. Water level monitoring system is one of the techniques to address the control of water wastage. LCD 20x4 line display. Since we know that the speed of sound is around 340m/s then we can calculate the distance using; To determine the level of the water in the tank we must know the total length of the tank. So, there is an overflow of water in the tank, which results wastage of energy and water. This design works on the premise that the home WiFi signal is accessible on the terrace near the water tank and mains power supply is available to power the Node MCU board. As P2 and P3 are immersed in water, we should get a non-zero voltage reading at P2 and P3, and zero voltage at P4. The second resistor (R2 - 22,000 ohms) acts as a pull down resistor and prevents input pin D4 from floating. The digital pins on the Node MCU board output 3.3V DC and hence a 330 Ohm current limiting resistor (R1) was used instead of the 440 Ohms used with the Arduino Nano board. We can observe that LEDs are glowing and the topmost blue LED will glow when the tank is filled thus, turning ON the buzzer. Manual/auto/off modes. We have to see how long the carbon electrodes work in real world scenario. if Pump stopped and Sump tank empty then Pump will stopped. Four lines are of the sensors and one is for Common Positive Pin. My colleague stays in an independent house and has a water tank on the terrace. In view of this, Bluetooth module based Water Level Monitoring system is an innovative idea that will inform the users about the level of liquid and will prevent it from overflowing. (A high resistance between GND and D4 grounds residual voltage without grounding the signal from P2). In auto mode: ( auto motor on and auto off) . LEDs will be monitoring the water level in the tank and the functionality of each LED is explained below : Presently, as the water ascends the sensors begin to get in contact with the water and the transistors are activated and there is a progression of current in the transistors making the LEDs light up. #define MOTORPIN 8 // Arduino pin tied to Relaypin of the Relay Circuit, #define BUZZER 9 // Arduino pin tied to +ve terminal of the Buzzer, float TankHeight, WaterLevelMAX, GapbwSonar, SonarReading, ActualReading, Temp. My colleague had WiFi connectivity in his upper floor and the WiFi signal strength on the terrace was at acceptable levels. The arduino provides a high signal of 10microseconds to this pin. And also to design a contactless water level indicator and controller using ultrasonic sensor with DRY PUMP RUN PROTECTION. http://xtel.in/water-level-monitor-using-sr04-and-labview.html. Sump Water level sensor, which are dipped in to the Sump Water Tank or Use non-contact sensor for Pump suction line, And Analog pin present on the Arduino Nano will be used to sense the presence of water. Pure water is a bad conductor of electricity and impurities in water improve conductivity. If Water level below 20% then Pump will start Running and. Interface for Serial Communication, 5pcs 3V~5V IIC I2C Logic Level Converter Module Bi-Directional Sensor Module for Arduino with Pins, 15 Ir Infrared Obstacle Avoidance Sensor, E18, D80Nk, PiBOX India Raspberry Pi 4 Heatsink, 3 Pieces Raspberry Pi Aluminum Heatsinks with Thermal Conductive Adhesive Tape for Raspberry Pi 4B Model B 3 Pieces, Embedded Kart TCS230 TCS3200 Color Recognition Sensor Detector Module for MCU Arduino. The next step would be to get a plastic enclosure to protect the board from rain when deployed on the terrace. There is a need to control the water wastage to save the environment and water resources. A more elegant solution that provides a programming interface would let the end user build different solutions of his/her choice. Once the design was validated with an Arduino board, the next step was to use a board with WiFi capability and send the water levels to a cloud hosted database. I built a AWS Lambda Function that writes the water level received over a HTTP API call to a DynamoDB table. The Node MCU (and ESP8266) has an onboard 10-bit Analog to Digital Converter (ADC). If the initial prototypes meet the end user needs, and if there is interest in this design, PCB fabrication could be done to make the final board look professional, To view or add a comment, sign in This could be done via a self hosted MQTT server or using a cloud service like AWS IoT core. We have successfully installed the device and it is indicating the water level in the tank. The data in the cloud can then be used to control a programmable switch to turn on/off the motor. #define MAX_DISTANCE 500 // Maximum distance we want to ping for (in centimeters). Fundamentally, the unit is comprised of different sensors going about as a switch. When you have a 'real' Christmas tree, it is important to keep it watered. I selected the CD74HC4067 16 channel multiplexer (for it's relatively low cost and the reasonably good switching speed). But it is a slightly better than electrodes corroding under water. Corrosion less sensors. This meant that the Mk1 design is not suitable for use in certain parts of the world and we had to go back to a new design. Stick the buzzer behind the PCB board and also fix the power supply by taking care of the transformer. However, the Node MCU board has one Analog pin and this would limit the number of input probes and the detected water levels to just one. Unlike the digital pin read which gives a login level HIGH or LOW based on a threshold, the analog pin provides a scaled value. In any case, everybody who has a water tank above knows the sort of issues that they face. It works on the principle of echolocation. A decent and very cheap office entrance door alarm system to keep track of every person's entry or departure. I tested this prototype with packaged drinking water and the results were as expected. The hole of the bare wire and bolt should be kept a minimum and in the event that you need, you can solder a little bit of wire to the common line just next to the nut and screw as the sensing would be more at the point when the water interacts with the normal wire and the bolt, there will be transfer of current from the stripped wire to the bolt and hence, the sensing part is complete. I am an Electrical Engineer who has a very innovative approach towards daily life stuff. Secondly, the controller is not programmable and handles the one task of turning off the motor.
The components used in this project are easily available in the market. I considered alternate methodologies for detecting water level, but they had practical issues and hence I had to go with the carbon probe with voltage detection. One of the major problems faced by most of the countries is the issue of water scarcity in the world. Digital pin D1 is set to output mode while pins D2, D5, D6, D7, D8 are set to input mode. Project tutorial by Pranav Kundaikar and Vinayak Shantaram Joshi. All the commercial products available on Amazon use a similar approach to detect water level. Water level detection (or liquid level detection) is not a new problem and there are a number of commercial off-the-shelf products available in the market. This ADC can map the input voltage to an integer between 0 to 1023. We discussed about having a smart sensor hooked to a programmable switch that can turn on/off the motor. As a first step I built a prototype to validate this idea with an Arduino Nano. However, this setup requires running electric wires from the controller located in the ground floor to the probes hanging in the water tank on the terrace. This may not be ideal depending on the house/apartment. Then cut the plastic board for the Power Switch. It works very long life. Choose that place which is out of reach of children and from where you can easily turn ON and OFF the switch. If P4 is hung close to the top of the tank, the motor can be turned off once non-zero voltage is detected at P4. Adding salt to the water resolved the problem. Most of these products use carbon/steel probes. Among all the components the most important components are Transistors BC 547. Free shipping on orders above Rs.499/- Dismiss, PiBOX India Raspberry Pi 4 8GB Jump Start8 Combo kit 4813W with Pi4 8GB, Pi4 Black case,16GB Noobs Card, BIS 3 amps Charger, Copper Heatsink, HDMI Cable, Ethernet Cable and Adapters 2022 Model, REES52 Ultrasonic Range Finder Module Sensor Distance Measuring Transducer New, PiBOX India Raspberry Pi 4 4GB Easy Cool 4 Combo kit 4413W with Pi4 4GB, Pi4 Fan case, Dual Speed Fan,16GB Noobs Card, BIS 3 Amps Charger, 3 Piece Heatsink, HDMI Cable and Accessories, Erratum Solutions FPM10A Fingerprint Reader-Sensor Module Arduino Locks. Presently for the establishment of the gadget, we should locate a reasonable spot for a clear view of LED lights. We need to put the circuit in a small box and make holes in it appropriately so that LEDs may come out of the box easily. In this example configuration, electricity is passed into water through probe P1 and voltage is measured at probes P2, P3 and P4. Level Monitoring and Control with dry Pump run protection using Ultrasonic Sensor and Android Application via bluetooth HC-05. It is this value that will enable us calibrate the tank.Here introduced a push button, this is used to measure the Tank height at the time of installation of this Circuit.
I decided to build a microcontroller based solution that detects and transmits the water level to a cloud hosted database. Firmly fix the rod inside the tank and make sure that the rod (PVC pipe) touches the bottom of the tank. Ive tackled it in a slightly different way sometime back, using an ultrasonic sensor. Level Monitoring and Control with dry Pump run protection using Ultrasonic Sensor and Android Applcation via bluetooth HC-05. The CD74HC4067 multiplexer has 4 data pins (S0, S1, S2, S3) that can be set to HIGH or LOW and the combination of the HIGH/LOW values determine the channel (C0 through C15) that is operational. I looked at a few products available on Amazon that detect water level and turn off the motor/pump (there are different variants that work with single phase motors and 3 phase motors). Awesome project. We will screw the two L hooks to the device and fix it into the wall and afterward take A/C 220V from any socket and give it to the board. if Pump running and Sump tank empty then Pump will stopped. I choose ESP8266 based Node MCU microcontroller board.
As we are using 5 digital pins in input mode, this circuit requires 5 pull down resistors. My colleague built a prototype with the Mk1 design and tested it at his home (in Trivandrum, Kerala). This unit will display the Water Level in percentage, Pump status, tank Height and Sump tank status.. MAX_DISTANCE 500 // Maximum sensor distance is rated at 400-500cm. Gap between Ultrasonic and Max water level adjusted in Arduino code. Buzzer, this is used to notify when the sump tank is empty. I decided to give this a shot and see if I can come up with a solution. After analyzing the circuit we came to know that five supply lines need to be taken out from the main circuit board to the sensor. These days everyone has an overhead tank at their homes. Keep rocking. Easy to install.
How To Detect Rainfall Using Rain Sensor? When the water is stored in the tank, no one can identify the level of water and also, no one can know when the water tank will be filled. #define TRIGGER_PIN 6 // Arduino pin tied to trigger pin on the ultrasonic sensor. Take a PCB board and solder the LEDs on it according to the levels defined above. Another problem Ive observed is with the diaphragm getting water vapour settled on it causing accuracy problems. // put your main code here, to run repeatedly: Water Quality Monitoring and Notification System, Christmas Tree Water Level via Cayenne and MKR1000. On getting to the surface of the water, the wave is echoed back to the sensor and the arduino reads the echo pin to determine time spent between triggering and receiving of the echo. A few months back I had a discussion with a colleague about the need for a water level sensor for his house. Subsequently the Mk2 prototype was tested in Trivandrum and was able to detect water level without the need for mixing salt. This can further used if you wish to replace the water tank with a new one. #define MAX_DISTANCE 500 // Maximum sensor distance is rated at 400-500cm. To resolve this type of problems by using implementation of water level monitors and control systems using wireless technology which will transmit the information to the smart phone and indicate the level of water in the overhead tanks. A single page application built with Google Charts helps users visualise the water level. Tank water level monitored in Android Mobile using app. The Node MCU board can also be stripped down further and could be powered by a battery, but we did not venture in that direction as power supply was available on the terrace.
The Arduino Nano was programmed to light the green on-board LED when the D4 pin reads logic level HIGH (1) and show the red LED when the D4 pin reads logic level LOW (0). How To Detect Water Level In The Overhead Tank Installed On Roof? Yet another very useful utility for day to day life. It observes the level of water and provides the information to the registered users through wireless. The output pin would send 5V DC voltage into the probe and water and the input pin would read the voltage and would give back logic level HIGH (1) if the voltage is above (2.6V) a threshold value. Project tutorial by Robodia Technology Solutions. This idea can be extended further to replenish the sump if we add water level sensors to the sump as well. percentage=(ActualReading/WaterLevelMAX*100); else if(percentage>20 && percentage<=100), if(percentage>20 && percentage<=100 && flag ==1), else if(percentage>20 && percentage<=100 && flag ==0), https://drive.google.com/file/d/11egiPu2fzW4Sn2ypX6yYpG9r5-iuY-TP/view?usp=sharing, https://drive.google.com/file/d/1_5t3tVkQNHQk60k0gRRFQR1lUCjvaC1z/view?usp=sharing. Now, that weve collected all the components lets assemble them and design the circuit. The scarcity is mainly due to the wastage of the water. Water level monitoring system is one of the techniques to address the control of water wastage. LCD 20x4 line display. Since we know that the speed of sound is around 340m/s then we can calculate the distance using; To determine the level of the water in the tank we must know the total length of the tank. So, there is an overflow of water in the tank, which results wastage of energy and water. This design works on the premise that the home WiFi signal is accessible on the terrace near the water tank and mains power supply is available to power the Node MCU board. As P2 and P3 are immersed in water, we should get a non-zero voltage reading at P2 and P3, and zero voltage at P4. The second resistor (R2 - 22,000 ohms) acts as a pull down resistor and prevents input pin D4 from floating. The digital pins on the Node MCU board output 3.3V DC and hence a 330 Ohm current limiting resistor (R1) was used instead of the 440 Ohms used with the Arduino Nano board. We can observe that LEDs are glowing and the topmost blue LED will glow when the tank is filled thus, turning ON the buzzer. Manual/auto/off modes. We have to see how long the carbon electrodes work in real world scenario. if Pump stopped and Sump tank empty then Pump will stopped. Four lines are of the sensors and one is for Common Positive Pin. My colleague stays in an independent house and has a water tank on the terrace. In view of this, Bluetooth module based Water Level Monitoring system is an innovative idea that will inform the users about the level of liquid and will prevent it from overflowing. (A high resistance between GND and D4 grounds residual voltage without grounding the signal from P2). In auto mode: ( auto motor on and auto off) . LEDs will be monitoring the water level in the tank and the functionality of each LED is explained below : Presently, as the water ascends the sensors begin to get in contact with the water and the transistors are activated and there is a progression of current in the transistors making the LEDs light up. #define MOTORPIN 8 // Arduino pin tied to Relaypin of the Relay Circuit, #define BUZZER 9 // Arduino pin tied to +ve terminal of the Buzzer, float TankHeight, WaterLevelMAX, GapbwSonar, SonarReading, ActualReading, Temp. My colleague had WiFi connectivity in his upper floor and the WiFi signal strength on the terrace was at acceptable levels. The arduino provides a high signal of 10microseconds to this pin. And also to design a contactless water level indicator and controller using ultrasonic sensor with DRY PUMP RUN PROTECTION. http://xtel.in/water-level-monitor-using-sr04-and-labview.html. Sump Water level sensor, which are dipped in to the Sump Water Tank or Use non-contact sensor for Pump suction line, And Analog pin present on the Arduino Nano will be used to sense the presence of water. Pure water is a bad conductor of electricity and impurities in water improve conductivity. If Water level below 20% then Pump will start Running and. Interface for Serial Communication, 5pcs 3V~5V IIC I2C Logic Level Converter Module Bi-Directional Sensor Module for Arduino with Pins, 15 Ir Infrared Obstacle Avoidance Sensor, E18, D80Nk, PiBOX India Raspberry Pi 4 Heatsink, 3 Pieces Raspberry Pi Aluminum Heatsinks with Thermal Conductive Adhesive Tape for Raspberry Pi 4B Model B 3 Pieces, Embedded Kart TCS230 TCS3200 Color Recognition Sensor Detector Module for MCU Arduino. The next step would be to get a plastic enclosure to protect the board from rain when deployed on the terrace. There is a need to control the water wastage to save the environment and water resources. A more elegant solution that provides a programming interface would let the end user build different solutions of his/her choice. Once the design was validated with an Arduino board, the next step was to use a board with WiFi capability and send the water levels to a cloud hosted database. I built a AWS Lambda Function that writes the water level received over a HTTP API call to a DynamoDB table. The Node MCU (and ESP8266) has an onboard 10-bit Analog to Digital Converter (ADC). If the initial prototypes meet the end user needs, and if there is interest in this design, PCB fabrication could be done to make the final board look professional, To view or add a comment, sign in This could be done via a self hosted MQTT server or using a cloud service like AWS IoT core. We have successfully installed the device and it is indicating the water level in the tank. The data in the cloud can then be used to control a programmable switch to turn on/off the motor. #define MAX_DISTANCE 500 // Maximum distance we want to ping for (in centimeters). Fundamentally, the unit is comprised of different sensors going about as a switch. When you have a 'real' Christmas tree, it is important to keep it watered. I selected the CD74HC4067 16 channel multiplexer (for it's relatively low cost and the reasonably good switching speed). But it is a slightly better than electrodes corroding under water. Corrosion less sensors. This meant that the Mk1 design is not suitable for use in certain parts of the world and we had to go back to a new design. Stick the buzzer behind the PCB board and also fix the power supply by taking care of the transformer. However, the Node MCU board has one Analog pin and this would limit the number of input probes and the detected water levels to just one. Unlike the digital pin read which gives a login level HIGH or LOW based on a threshold, the analog pin provides a scaled value. In any case, everybody who has a water tank above knows the sort of issues that they face. It works on the principle of echolocation. A decent and very cheap office entrance door alarm system to keep track of every person's entry or departure. I tested this prototype with packaged drinking water and the results were as expected. The hole of the bare wire and bolt should be kept a minimum and in the event that you need, you can solder a little bit of wire to the common line just next to the nut and screw as the sensing would be more at the point when the water interacts with the normal wire and the bolt, there will be transfer of current from the stripped wire to the bolt and hence, the sensing part is complete. I am an Electrical Engineer who has a very innovative approach towards daily life stuff. Secondly, the controller is not programmable and handles the one task of turning off the motor.