Plant need water but many time we forget.
For this problem we have made a Simple DIY Automatic Plant Watering Circuit
Project use soil sensor, small pump, MOSFET and some parts.
System checks soil wet or dry and pump start only when soil is dry.
Circuit is very easy with no Arduino and with no microcontroller needed.
Circuit Working:
Parts List:
| Component Name | Value | Quantity |
|---|---|---|
| Resistors | 10k 1/4 watt | 1 |
| Preset 50k | 1 | |
| Semiconductors | MOSFET IRFZ44N | 1 |
| Water Pump 3V DC Mini Pump | 1 | |
| Soil Moisture Sensor | 1 | |
| Battery 3.7V Li-ion / LiPo | 1 | |
| On/Off Switch | 1 |
Soil moisture sensor is main part of this circuit.
Sensor check soil is wet or dry.
Dry soil make high resistance between probes.
This gives voltage to MOSFET gate.
MOSFET IRFZ44N act like electronic switch.
High sensor output turns ON MOSFET and pump start.
Wet soil gives low signal and pump stops.
Preset VR1 set sensitivity of soil detect.
10k resistor keep MOSFET gate stable.
Formula:
Formula for automatic plant watering circuit is below.
Soil resistance changes with water.
Dry soil has high resistance in kilo ohm.
Wet soil has low resistance in hundreds of ohm.
Use Ohm law: V = I * R.
Sensor give 2.5V in dry with 0.5V in wet.
MOSFET gate need 2 to 4V to turn ON.
Dry soil with voltage high makes MOSFET ON.
Pump work from 3.7V battery.
Pump take 100 to 300mA current.
10k resistor make gate 0V when there is no signal.
How to Build:
To build a Simple DIY Automatic Plant Watering Circuit follow the below steps for connections:
- Take all the parts as mentioned in the circuit diagram above.
- Soil sensor two pins go to MOSFET gate and source.
- Preset one side go to 3.7V positive with pump and other side to 10k resistor and MOSFET gate.
- Pump other side connect to MOSFET drain.
- MOSFET source connect to soil sensor one pin and GND.
- Soil sensor other pin go to MOSFET gate.
Conclusion:
This project for Simple DIY Automatic Plant Watering Circuit is very simple and with very low cost.
No Arduino and no coding is used.
It work with only sensor, MOSFET, pump and resistors.
It save water and keep plant good.
Water come only when soil is dry.
Anyone can make this circuit at home with small parts and with little money.