~ Sundaresan
Introduction
Monitoring water levels can be a fun, hands-on learning and an educational project, especially for students learning about electronics and programming. In this project, we used an ultrasonic sensor and an Arduino UNO board to measure water levels in a bucket, indicating the levels with different colored LEDs.
Classroom Experience
During the class, students filled the bucket with water and observed the LED indicators. When the water level was low, the Red LED glowed. When the bucket was half-full, the Blue LED lit up. If the water level was high, the Green LED illuminated.
Students engaged deeply with the project, experimenting with the Scratch code to make all LEDs glow simultaneously and turning off all LEDs under certain conditions. This interactive experience allowed students to explore and learn about water level sensing and coding.
Adding a Buzzer for Alarm
Inspired by the practical application shared by 8th class teacher Thenmozhi, we plan to add a buzzer to the circuit. Once the water tank is full, the buzzer will sound an alarm to indicate it’s time to turn off the motor. This addition will help students understand the real-world application of their project.
Exploring Sound Types
This project involved the use of an ultrasonic sensor, which is a type of sound wave. Here’s the different types of sounds which children learnt from this project.
Infrasonic sounds: Below 20 Hz, felt as vibrations, Elephants use infrasonic sounds to communicate over long distances.
Sonic sounds: 20 Hz to 20 kHz, audible to humans, used in everyday communication and entertainment.
Ultrasonic sounds: Above 20 kHz, inaudible to humans. Bats use ultrasonic sounds for echolocation to navigate and hunt for insects in the dark.
Supersonic sounds: Related to objects traveling faster than the speed of sound, resulting in sonic booms and used in high-speed aerodynamics. Supersonic jets travel faster than the speed of sound.
Components Required
- Ultrasonic sensor (HC-SR04)
- Arduino UNO board
- Breadboard
- Connecting wires
- LEDs (Red, Blue, Green, and another for full level indication)
- Resistors
- Buzzer (for future extension)
Setup
- Assemble the Hardware:
- Fit the ultrasonic sensor at the top of the bucket.
- Connect the sensor to the Arduino UNO board.
- Attach the LEDs to the board through appropriate resistors.
- Connect the components on the breadboard using connecting wires.
- Connections:
- Ultrasonic Sensor:
- VCC to 5V
- GND to GND
- Trig to Digital Pin 2
- Echo to Digital Pin 3
- LEDs:
- Red LED to Digital Pin 13
- Blue LED to Digital Pin 12
- Green LED to Digital Pin 11
- Full-level indication LED to Digital Pin 10
- Ultrasonic Sensor:
Coding
Here’s the code used in this project, generated by PictoBlox: