Circuit Diagram
How to Build It
- Connect the soil-moisture sensor module to power (VCC/GND).
- Connect the module's digital output to a BC547 transistor's base, through a resistor.
- Connect the transistor's collector to a buzzer and then to the positive rail.
- Connect the emitter to GND.
- Insert the sensor probes into dry soil — the buzzer should sound.
- Water the soil — the buzzer should stop.
Bill of Materials
| Product | Code | Qty |
|---|---|---|
| Buzzer | LD-BZPG-2312 | 1 |
| Electronic module (sensor/relay/converter/control) | OKY3442 CL73 | 1 |
| Resistor | DR47K-8/9 | 1 |
| Transistor (incl. IGBT) | — | 1 |