A fully hardware-based Automated Plant Watering System designed using Digital Logic circuits without using any microcontroller or programmable device.
- Detects soil moisture automatically
- Activates the water pump when the soil becomes dry
- Uses a timed watering cycle
- Implemented entirely with 74LS TTL ICs
- Simulated in Proteus and verified on hardware
- 74LS08 (AND Gate)
- 74LS32 (OR Gate)
- 74LS04 (NOT Gate)
- 74LS74 (D Flip-Flop)
- 74LS163 (Decade Counter)
- NE555 Timer
- Soil Moisture Sensor
- BC547 Transistor
- 5V Relay
- Mini DC Water Pump
- LEDs, Resistors, Capacitors, Breadboard
Proteus/- Proteus simulation filesImages/- Circuit and hardware imagesVideo/- Demonstration videoREADME.md- Project description
The Automated Plant Watering System continuously monitors the moisture level of the soil using a soil moisture sensor. When the soil is moist, the system remains idle and the pump stays OFF.
When the soil becomes dry, the sensor indicates that watering is required. This signal is processed by the digital logic circuit, which sets the 74LS74 D Flip-Flop and turns the pump ON through a relay driver. At the same time, an NE555 timer starts generating clock pulses for the 74LS163 4-bit binary counter.
The counter is configured to count for approximately 20 seconds. During this period, the pump remains active and the system does not continuously check the moisture level. Even if the soil becomes sufficiently moist before the 20-second interval is completed, the counter continues counting until the end of the cycle. The Water Needed indicator turns OFF as soon as the moisture requirement is met, showing that the soil is no longer dry, but the pump keeps running until the counter finishes its current cycle.
Once the counter reaches its terminal count, it resets the flip-flop and turns the pump OFF. Only after the completion of this cycle does the system check the soil moisture again. If the soil is still dry, another watering cycle begins; otherwise, the system remains idle until dry soil is detected again.
The 20-second watering duration was chosen as a simple and practical value for this small-scale academic project. It is not a fixed requirement and can be increased or decreased by adjusting the timer frequency or modifying the counter configuration according to the size of the plant and watering needs.
The entire system is implemented using digital logic components without using any microcontroller or programmable device.
The project was successfully simulated in Proteus and implemented on a breadboard. Hardware results matched the simulation outputs for all tested cases.
Watch the working demonstration in the Video/ folder.
- Muhammad Zulqarnain (Repository Maintainer)
- Ahmed Tariq
- Ali Imran