E&TC / ECE · Agriculture electronics · Final year project
ATmega Based Plant Irrigation System using Capacitive Moisture Sensor
Automatic plant watering with a capacitive soil moisture sensor. An ATmega328P reads soil moisture and switches a water pump through a relay when the soil is dry, stopping it once the soil is wet enough. Capacitive sensors do not corrode like resistive probes.
What is the ATmega Based Plant Irrigation System using Capacitive Moisture Sensor project?
Automatic plant watering with a capacitive soil moisture sensor. An ATmega328P reads soil moisture and switches a water pump through a relay when the soil is dry, stopping it once the soil is wet enough. Capacitive sensors do not corrode like resistive probes.
Key facts
- Branch
- Electronics & Telecommunication (E&TC / ECE); also suits Instrumentation
- Domain
- Agriculture electronics projects
- Type
- Final year project · Intermediate
- Suitable for
- Diploma capstone and B.E / B.Tech final year
- Build time
- 4 to 6 weeks
- Estimated component cost
- ₹2,200 – ₹3,300
- Guidance from
- ₹9,999 (Hardware / IoT Final Year)
How the ATmega Based Plant Irrigation System using Capacitive Moisture Sensor works
- 12 V power adapter / step-down transformer supplies the circuit; a regulator gives the controller and sensors a steady 5 V.
- The ATmega328P microcontroller with base board is the brain of the circuit: it samples the sensors, compares readings with set limits and switches the outputs.
- The Mini submersible water pump moves water for irrigation, dispensing or cooling.
- The Relay module switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal.
- The 16×2 LCD with I2C adapter shows readings, status and messages to the user.
Block diagram
Controller
ATmega328P microcontroller with base boardOutputs
Mini submersible water pumpRelay module16×2 LCD with I2C adapterComponents list and cost
Typical prices from Indian online stores and electronics markets (Lamington Road, Budhwar Peth, SP Road). Buy from one store where you can to save on shipping.
| Component | Qty | What it does | Approx. cost |
|---|---|---|---|
| ATmega328P microcontroller with base board | 1 | Is the brain of the circuit: it samples the sensors, compares readings with set limits and switches the outputs. | ₹350 |
| Mini submersible water pump (12 V) | 1 | Moves water for irrigation, dispensing or cooling. | ₹180 |
| Relay module | 1 | Switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal. | ₹70 |
| 16×2 LCD with I2C adapter | 1 | Shows readings, status and messages to the user. | ₹220 |
| 12 V power adapter / step-down transformer | 1 | Supplies stable low-voltage power from the mains. | ₹250 |
| Passive components, PCB and wiring kit | 1 | Resistors (assorted), capacitors (assorted), PCB / breadboard and cables, connectors and jumper wires. | ₹310 |
| Wiring, PCB, soldering and enclosure | 1 | Project overhead | ₹450 |
| Demo model base / mounting board | 1 | Project overhead | ₹500 |
| Testing spares and replacements | 1 | Project overhead | ₹300 |
| Estimated total | Varies with brand, quality and city | ₹2,200 – ₹3,300 |
Prices are estimates for budgeting. We confirm the bill of materials when your design is frozen, and components are charged at actual cost with bills.
How much does this project cost?
| Option | What you get | Cost |
|---|---|---|
| Components only | You buy the parts and build it yourself | ₹2,200 – ₹3,300 |
| Hardware / IoT Final Year | Working model or guided build, Circuit diagram and bill of materials, Firmware / code with explanation | from ₹9,999 + components |
| Capstone Project (CPE) | Working project or model, Black book in MSBTE format, Step-by-step explanation | ₹9,999 + components |
| Diploma ITR | 100% working source code, Project report PDF, PPT | ₹1,999 + components |
No GST and no hidden charges. Use the cost calculator for a quote with your deadline and add-ons, or see all plans.
Download the project brief (PDF)
Summary, working, components and cost and viva questions on one branded PDF to show your guide or team. To get it developed, contact us on WhatsApp.
What you submit with this project
- Working model with circuit diagram and program code
- Project report or black book in your university's chapter order (block diagram, circuit, calculations, results)
- Presentation for the review and final viva
- Synopsis for topic approval, if your college asks for one
E&TC / ECE viva questions on this project
What is the aim of the ATmega Based Plant Irrigation System using Capacitive Moisture Sensor project?
Automatic plant watering with a capacitive soil moisture sensor. An ATmega328P reads soil moisture and switches a water pump through a relay when the soil is dry, stopping it once the soil is wet enough. Capacitive sensors do not corrode like resistive probes.
Explain the working of your project in short.
12 V power adapter / step-down transformer supplies the circuit; a regulator gives the controller and sensors a steady 5 V. The ATmega328P microcontroller with base board is the brain of the circuit: it samples the sensors, compares readings with set limits and switches the outputs. The Mini submersible water pump moves water for irrigation, dispensing or cooling. The Relay module switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal.
Why is a microcontroller used in this project?
A microcontroller combines a CPU, memory and I/O pins on one chip, so a single low-cost IC can read sensors, make decisions in code and control loads without a computer.
How is the pump switched by the controller?
Through a relay or MOSFET, because the pump runs at 12 V and draws more current than the controller pin can provide.
Why is a relay used?
It electrically isolates the 5 V control circuit from the high-voltage load. The controller energises the coil through a transistor, and the contacts switch the load.
Why is an I2C adapter used with the LCD?
It reduces the wiring from about 10 pins to 2 (SDA and SCL), leaving more controller pins free for sensors.
How is 230 V AC converted to 5 V DC for the circuit?
A transformer steps down the voltage, a bridge rectifier converts AC to pulsating DC, a capacitor smooths it and a 7805 regulator gives a steady 5 V.
Explain the block diagram of your project.
The input section senses the real-world quantity, the ATmega328P microcontroller with base board processes it according to the program, and the output section displays the result and drives the actuators. The power supply section feeds every block.
Which communication protocols are used between the modules?
I2C for the display, RTC or motion sensor (only SDA and SCL lines) and analog inputs read by the ADC for the analog sensors. Each protocol was chosen because the module supports it and it uses the fewest pins.
What is the operating voltage of the circuit?
The controller and most sensors work at 5 V (ESP boards and some modules at 3.3 V). A 12 V adapter powers the board, and a regulator steps it down. Motors and relays get their own supply line so they do not reset the controller.
What is the difference between accuracy and precision?
Accuracy is how close a reading is to the true value. Precision is how close repeated readings are to each other. A sensor can be precise but inaccurate if it is not calibrated.
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