Soil Moisture Sensor Kit – HW-103 Controller & HW-080 Probe

The HW-103 and HW-080 soil moisture sensor kit combines analogue and digital outputs with a two-prong resistive probe for DIY electronics projects. Use it to explore soil-moisture changes, build plant-monitoring experiments and develop microcontroller-based watering reminders. The kit includes the separate controller board, sensing probe and two female-to-female jumper leads for the probe connection.

Build practical soil-monitoring projects

• Monitor changes in the moisture of potting mix during a controlled experiment.
• Develop a plant-watering reminder with a compatible microcontroller and your own program.
• Explore resistance, conductivity and sensor calibration in an electronics lesson.
• Position the sensing probe in the soil while keeping the separate controller board dry.

Features of the Soil Moisture Sensor Kit

• HW-103 controller board and HW-080 sensing probe.
• Analogue output (AO) for reading changes in the sensor signal.
• Digital output (DO) for a high/low sensor indication.
• Two-prong resistive probe for contact with the growing medium.
• Separate sensor and controller boards.
• Two female-to-female jumper leads for connecting the probe to the controller board.
• Pre-fitted male pin headers on both boards.
• Onboard adjustment trimmer, power indicator and switching indicator LEDs.
• Mounting hole on the controller board and two mounting holes on the probe.
• Suitable for educational projects and electronics prototyping.
• Intended for relative soil-moisture monitoring with additional electronics.

Technical Specifications

Compatibility

• Compatibility: DIY microcontroller projects with a suitable supply and input interface.
• Limitations: Requires additional electronics; not a standalone moisture meter or pump controller.

Physical Specifications

• Product Type: Resistive soil moisture sensor kit.
• Controller Board Marking: HW-103.
• Probe Marking: HW-080.
• Sensing Method: Electrical resistance through the medium between the probe electrodes.
• Construction: Separate controller board and two-prong probe.
• Mounting: One controller-board mounting hole and two probe mounting holes.

Connectivity

• Controller Connections: Two-pin male probe header and four-pin right-angle male header labelled VCC, GND, DO and AO.
• Outputs: Analogue sensor output (AO) and digital sensor output (DO).
• Probe Connection: Two-pin male header.
• Supplied Leads: Two female-to-female jumper leads.

Package Information

• Included Items: One HW-103 controller board, one HW-080 probe and two jumper leads.
• Sold As: One sensor kit.
• Condition: New.
• Applications: Plant monitoring, watering reminders, electronics education, sensor experiments.

Compatibility

Designed for integration into DIY sensing projects. Match the sensor's supply requirements and output levels to the selected controller before connecting it. The two included jumper leads connect the probe to the controller board. Additional leads are required for the controller's power and signal connections. Where a microcontroller is used, an appropriate program is also needed to interpret the sensor readings.

Do not apply a 5 V signal directly to an input that is rated for 3.3 V only. Check the analogue-input limits of the particular development board as well as its digital-input limits.

While unfamiliar with your devices, we offer a 14-day 'trial and return for refund less shipping fee' service to enable testing in your environment with your equipment.

Controller Pin Reference

Follow the printed labels when wiring. The end pin beside the HW-103 marking is AO; the sequence from that end is AO, DO, GND, VCC. AO and DO are outputs from the sensor board and connect to inputs on the receiving controller. Neither is a power connection for a pump or valve.

Check the receiving input's permitted voltage range before connecting either output. A digital-only GPIO cannot measure the voltage on AO as an analogue reading; use an ADC input. Establish the dry and damp readings in your own setup before deciding which signal level means watering is needed.

Limitations

• Relative readings: This kit does not provide a factory-calibrated percentage of soil water content. Establish useful reference readings in your own growing medium.
• Soil conditions affect results: Conductivity, fertiliser and probe placement can affect the reading. Keep the insertion depth and position consistent when comparing measurements.
• Probe corrosion: Exposed resistive electrodes can deteriorate with use, particularly when continuously powered in wet soil. Best suited to experiments and intermittent measurements.
• Keep the electronics dry: Put only the sensing portion of the probe into the growing medium. Protect the controller board, connectors and upper probe connections from water.
• Additional hardware required: The kit does not directly operate a pump or watering valve. A complete watering project needs suitable control and switching hardware.
• Soil moisture only: It does not measure soil pH, nutrient concentration or air humidity.

Getting useful readings

• Confirm the board's supply rating and the receiving controller's input voltage limits. Disconnect power while changing connections.
• Connect the two probe pins to the controller's separate two-pin probe header using the included jumper leads.
• Connect VCC and GND to a suitable supply, with a common ground to the receiving controller. Use AO with an ADC input, or DO with a compatible digital input.
• Once correctly connected and powered, compare the output in relatively dry and damp samples of the growing medium you intend to use.
• Keep the probe insertion depth consistent and establish a useful watering threshold for your project.
• Recheck the reference readings when changing the soil, fertiliser or probe.
• If readings become erratic, check the connections, soil contact and condition of the electrodes.

Frequently Asked Questions (FAQs):

Q. Is this a complete soil moisture meter?
A. No. It is a controller-board and probe kit for integration into an electronics project. A standalone display or finished plant-monitoring system is not included.

Q. Are connecting wires included?
A. Yes. Two female-to-female jumper leads are included for the probe-to-controller connection. Additional wiring is required to connect the controller board to your project.

Q. What is the difference between AO and DO?
A. AO is the analogue output, while DO is the digital output. Read AO with a suitable ADC to observe the sensor voltage; read DO with a compatible digital input for a high/low indication. Neither output is a serial data connection.

Q. Does it display a soil moisture percentage?
A. No. The kit has no numerical display. A project can convert readings into a relative scale after calibration, but that scale is not automatically a measurement of volumetric water content.

Q. Is the HW-080 probe capacitive?
A. No. This two-prong probe uses resistive sensing through the growing medium between its exposed electrodes.

Q. Can it water my plants automatically?
A. It can form the sensing part of a DIY watering project. It does not supply a pump, valve, switching circuit or finished watering program.

Q. Can the controller board get wet?
A. Keep the controller board and electrical connections dry. Only the sensing portion of the probe should contact the growing medium.

Q. Will the probe last indefinitely in wet soil?
A. No. Exposed resistive electrodes can corrode and their readings can change over time. Inspect the probe and recalibrate or replace it when its performance deteriorates.

Package Includes

1x HW-103 soil moisture sensor controller board.
1x HW-080 soil moisture sensing probe.
2x female-to-female jumper leads.

Does not include a microcontroller, power supply, display, pump, watering valve, enclosure or additional power-and-signal connection leads.

Product Disclaimer

HW-103 and HW-080 identify the board and probe supplied. References to other equipment describe intended project use and do not imply endorsement or affiliation. All trademarks and brand names are the property of their respective owners, and any use of these names is solely for descriptive purposes.