ARVACORE: An IoT-Based Irrigation Monitoring and Automated Water Management System for Rice Cultivation
The Rice Agronomy Challenge & Field Monitoring Problem
Rice cultivation in the Philippines relies predominantly on traditional continuous flooding, submerging fields under standing water throughout the season. This practice requires massive freshwater allocation and demands frequent, time-consuming manual field visits by farmers to inspect water levels across dispersed paddies.
The Limits of Manual Field Observation
In traditional Philippine rice farming, maintaining continuous standing water throughout the vegetative phase remains standard practice. However, unmonitored flooding causes excessive water loss through deep percolation and continuous evaporation, placing significant strain on local canals and pumping systems.
In communities like Barangay Silang in Lopez, Quezon, farmers manage plots with varying microtopography. Water allocation through shared communal pumps requires coordinated scheduling, but farmers currently lack continuous quantitative feedback regarding perched water depths and root-zone moisture depletion.
Sensing Field Hydrology & Subsurface Moisture
Understanding when to irrigate requires tracking two critical physical parameters: the perched water elevation relative to the field mud line, and the volumetric moisture content in the active root horizon (down to -15 cm).
By coupling non-contact acoustic distance measurement inside a perforated stilling well with subsurface capacitive moisture probing, ArvaCore provides objective, continuous telemetry—replacing manual field guessing with verifiable hydrological data.
The Physical Domain & Configurable Field Monitoring Nodes
To overcome the microtopographical unevenness and soil variability typical of Philippine lowland paddies, ArvaCore avoids single-point sensing in favor of a configurable network of modular field-monitoring nodes (N sensor nodes) deployed across representative paddy zones.
Microcontroller Platform
Each field node features a dedicated microcontroller board providing digital and analog I/O alongside wireless radio capabilities. The MCU periodically samples water-level distance transducers and soil moisture probes, computes running averages to filter ripple noise, and packages serialized frames for transmission to the field gateway.
Ultrasonic Acoustic Echo Transducer
Measures the physical distance between the transducer and the ponded water surface by emitting high-frequency ultrasonic acoustic pulses (40 kHz) and calculating the round-trip time-of-flight. Mounted above the paddy inside an open perforated field well to protect against wind ripples and foliage interference while maintaining non-contact reliability.
Subsurface Soil-Moisture Sensor
Inserted into the root horizon (0 to -15 cm depth) to quantify volumetric water content (VWC) in the soil matrix. When surface ponding recedes below 0 cm, this sensor verifies whether moisture remains available to rice roots or if immediate reflooding is necessary to prevent crop stress.
Weatherproof Field Enclosure & Power
Deployed in exposed, humid, and mud-prone paddy environments. Electronics are housed in sealed IP-rated enclosures mounted on rigid agricultural stakes with perforated stilling wells anchoring into the mud to create a calm water column.
Farm-to-Digital System Architecture
Derived strictly from Thesis Figure 3, the architecture illustrates the end-to-end telemetry pipeline: from physical paddy soil-water dynamics across configurable field-monitoring nodes, through the IoT gateway and cloud application server, to the closed-loop centralized irrigation pump and inline flow verification sensor.
Modular field units deployed at designated paddy locations. Each ArvaNode houses a low-power microcontroller, an ultrasonic distance sensor in a stilling well, a soil moisture probe, and a wireless transceiver. The node count is configurable according to parcel size and topography.
Field Conditions (Rice Paddy)
ArvaNode: Field Monitoring Nodes
Modular field units deployed at designated paddy locations. Each ArvaNode houses a low-power microcontroller, an ultrasonic distance sensor in a stilling well, a soil moisture probe, and a wireless transceiver. The node count is configurable according to parcel size and topography.
ArvaNet: Internet Gateway & Wi-Fi
Application Server & Database
ArvaLink: Web Dashboard & Mobile App
User (Farmer / Operator)
Centralized Irrigation Mechanism
In-Line Flow Sensor
Closed-Loop Irrigation Logic & Water-Level Threshold Simulation
The core operational intelligence of ArvaCore is governed by a finite closed loop. In accordance with Thesis Figure 2, sensor readings drive real-time comparison against water-level thresholds. When water recedes below the critical safe boundary, the system actuates the pump, verifies fluid flow, and maintains pumping until the reflooded target depth is restored.
Evaluation Approach & Technical Benchmarks
The evaluation of ArvaCore focuses on assessing its performance, reliability, and usability in the context of agricultural monitoring for lowland rice farming. Rather than reproducing exhaustive survey instruments, the approach generalizes key criteria drawn from the research methodology and Technology Acceptance Model (TAM).
| PARAMETER | OBJECTIVE | TARGET BENCHMARK | FORMULA / CRITERIA |
|---|---|---|---|
| Ultrasonic Water-Level Accuracy | Distance Measurement Validation | ±5% | Percentage error comparison vs calibrated physical depth reference |
| Pump Activation/Deactivation Accuracy | Actuation Reliability | ≥ 95% | Across repeated controlled test trials |
| System Response Time | Real-Time Responsiveness | ≤ 30 seconds | Time from threshold detection to command execution |
| Flow Sensor Verification (MAPE) | Hydraulic Validation | Target MAPE ≤ 5% | MAPE = (100/n)·∑|actual_i - measured_i|/actual_i |
Assesses the accuracy of ultrasonic water-level tracking, soil moisture readings, and the responsiveness of automated pump activation and shutoff under controlled field trials.
Comparative bench trials against physical depth benchmarks and calibrated reference instruments.
Evaluates the consistency of wireless data transmission between field nodes, local gateway transceivers, and cloud servers across humid, open agricultural conditions.
Continuous signal logging, packet delivery rate auditing, and hardware stability testing over repeated cycles.
Gathers structured user feedback from local rice farmers and agricultural practitioners regarding dashboard readability, alert comprehensibility, and overall system ease of operation.
Guided field interaction sessions, semi-structured usability interviews, and Technology Acceptance Model (TAM) survey assessments.
Measures the practical utility of remote monitoring in reducing avoidable in-person field inspections, supporting timely water decisions, and integrating with existing irrigation habits.
Field observation reports, operational feedback logs, and comparative workflow assessments.
What ArvaCore Could Make Possible
The potential benefits outlined below represent anticipated outcomes to be assessed during testing and deployment. They reflect the system's design intent rather than confirmed results, grounded in its IoT-based agricultural monitoring capabilities.
Potential Benefits for Rice Farmers
Providing rice farmers with real-time access to actual field water and soil conditions through an accessible web interface, supporting faster and more confident irrigation management.
- ▸Remote visibility into paddy water elevation and soil moisture curves without requiring twice-daily trek visits.
- ▸Timely alerts when water drops below configured critical levels, helping prevent unintended root-zone moisture stress.
- ▸Potential reductions in routine manual monitoring travel, labor time, and operating fuel costs.
- ▸Data-supported irrigation decisions rather than relying solely on visual guesswork across spread-out plots.
Environmental & Resource Management Potential
Continuous digital records help farmers understand actual water consumption trends and plan irrigation more deliberately.
- ▸Empirical tracking of perched water elevation and subsurface soil moisture retention over full crop cycles.
- ▸Historical trend logging providing an objective basis for evaluating and comparing different irrigation schedules.
- ▸Sensor-informed pumping helps avoid excessive over-irrigation and minimizes unnecessary water withdrawal from local canals or aquifers.
- ▸Foundational telemetry architecture supporting future research into water-use efficiency and ecological impact.
Potential for Irrigation Communities
In agricultural cooperatives and shared irrigation systems, transparent field data can help farmers coordinate water allocation and maintenance.
- ▸Shared visibility into field conditions across multiple parcel quadrants to improve pumping schedules.
- ▸Objective historical records to inform cooperative discussions on water allocation and pump maintenance costs.
- ▸Early detection of flow anomalies or delivery disruptions in shared irrigation supply lines.
- ▸A practical reference for community-level digital monitoring in agrarian agrarian settings.
Scientific & Engineering Research Value
The project provides an open, documented case study for deploying low-power IoT sensing and closed-loop control in tropical agricultural environments.
- ▸Bench-testing and field validation of ultrasonic distance sensors and soil moisture probes in humid paddy environments.
- ▸Evaluating low-power wireless transmission reliability across open agricultural terrain.
- ▸Assessing the usability and adoption factors of agricultural dashboards among rural farming practitioners.
- ▸Documenting field challenges, hardware resilience, and integration requirements for future agricultural IoT researchers.
Help Bring ArvaCore to the Field
ArvaCore is progressing toward prototype completion and planned field deployment in Barangay Silang, Lopez, Quezon Province. The preliminary funding target is ₱25,000 to help bring the system closer to practical field evaluation.
Ways to Support ArvaCore
Help bring ArvaCore from prototype development toward field deployment in Barangay Silang, Lopez, Quezon Province.
The project requires hardware, supporting components, deployment preparation, and field-testing resources to move toward practical evaluation.
Monetary Contributions
Provide financial support for essential component purchases, hardware assembly, connectivity, transportation, deployment preparation, and related expenses.
In-Kind Hardware Contributions
Contribute compatible sensors, microcontrollers, communication modules, solar-power components, batteries, enclosures, wiring, or connectors.
Component and Subsystem Sponsorships
Sponsor specific items within ArvaCore, ArvaNode, or ArvaNet. Coordinate component specifications with the project team.
Technical Collaboration
Discuss hardware sourcing, engineering guidance, testing resources, deployment logistics, or technical collaboration with the project team.
ArvaCore is seeking ₱25,000 in financial and in-kind support. No funds have been received to date, and online donations are not yet enabled — please contact the project team to discuss support.
The breakdown below lists the estimated expenses for prototype completion and planned field deployment in Barangay Silang, Lopez, Quezon Province.
ArvaNode
| ITEM | STATUS | COST (PHP) | NOTES |
|---|---|---|---|
| ESP8266 Microcontroller Board | PRELIMINARY | ₱150 | Low-power Wi-Fi microcontroller unit for sensor acquisition |
| Soil Moisture Sensor Probe | PRELIMINARY | ₱170 | Root-zone moisture detection probe |
| HC-SR04 Ultrasonic Distance Sensor | PRELIMINARY | ₱55 | Acoustic ToF water elevation transducer |
| 18650 Battery Holder | PRELIMINARY | ₱29 | Single-cell battery carrier |
| Solar Panel (Field Unit) | PRELIMINARY | ₱299 | Photovoltaic recharging unit for field autonomy |
| 134N3P Boost / Charging / Protection Module | PRELIMINARY | ₱28 | Battery charge management & 5V boost circuit |
| PKCell 18650 Rechargeable Battery | PRELIMINARY | ₱185 | Lithium-ion energy storage cell |
| Miscellaneous Allowance (Wiring & Passive Components) | PRELIMINARY | ₱100 | Connectors, resistors, heat shrink, terminal blocks |
ArvaNet
| ITEM | STATUS | COST (PHP) | NOTES |
|---|---|---|---|
| ESP32-WROOM-32 DevKit Board | PRELIMINARY | ₱299 | Dual-core MCU for gateway packet routing & management |
| 900 MHz External Antenna | PRELIMINARY | ₱300 | High-gain omnidirectional wireless antenna |
| Air780E Cat-1 4G LTE Cellular Module | PRELIMINARY | ₱750 | WAN uplink transceiver for remote cloud server connectivity |
| E32-900T20D V8 LoRa / Sub-GHz Transceiver | PRELIMINARY | ₱675 | Long-range field telemetry RF transceiver |
| 18650 4-Cell Battery Holder | PRELIMINARY | ₱79 | Multi-cell battery pack holder |
| Solar Panel (Gateway Unit) | PRELIMINARY | ₱299 | Continuous solar power replenishment for hub |
| CN3065 Solar Lithium Battery Charger | PRELIMINARY | ₱80 | Solar MPPT charging controller board |
| Battery Protection & BMS Board | PRELIMINARY | ₱89 | Over-discharge, short-circuit & balancing protection |
| Four PKCell 18650 Batteries (Combined Set) | PRELIMINARY | ₱680 | Combined set of 4 rechargeable 18650 cells for gateway pack |
| XL6009 / LM2577 DC-DC Boost Converter | PRELIMINARY | ₱59 | Voltage stabilization for cellular and RF modules |
| Miscellaneous Allowance (Antenna Feed & Cables) | PRELIMINARY | ₱100 | SMA pigtails, headers, and enclosure cabling |
ArvaCore
| ITEM | STATUS | COST (PHP) | NOTES |
|---|---|---|---|
| ESP32-WROOM-32 DevKit Actuation Board | PRELIMINARY | ₱299 | Core controller board for pump actuation & flow signal handling |
| Optocoupled Industrial SPDT Relay Actuation Module | ESTIMATED | ₱380 | High-current galvanic isolation module triggering pump contactor |
| In-Line Hall-Effect Turbine Water Flow Sensor & Couplers | ESTIMATED | ₱850 | Pipe flow meter and plumbing adaptors for volumetric verification |
Assembly & Deployment
| ITEM | STATUS | COST (PHP) | NOTES |
|---|---|---|---|
| IP66 Weatherproof Enclosures & Perforated PVC Stilling Wells | ESTIMATED | ₱2,450 | Waterproof electrical boxes, cable glands, and field water tubes for stilling water surface |
| Field Mounting Hardware, Brackets & Ground Staking Apparatus | ESTIMATED | ₱1,650 | Corrosion-resistant aluminum brackets, stakes, and outdoor cable ties |
| Cellular SIM Data, Connectivity Allowance & Cloud Host Setup | ESTIMATED | ₱1,850 | Field data telemetry SIM cards and prototype cloud database instances |
| Field Assembly Consumables, Solder, Gaskets & Heatshrink | ESTIMATED | ₱1,100 | Silicone marine sealant, terminal strips, test leads, and potting compound |
| Transportation, Field Testing & Farmer Calibration Logistics | ESTIMATED | ₱3,200 | Travel and transport to Barangay Silang, Lopez, Quezon and on-site testing supplies |
Contingency
| ITEM | STATUS | COST (PHP) | NOTES |
|---|---|---|---|
| Contingency Allowance for Component Price Variation & Spares | ESTIMATED | ₱1,795 | Reserve buffer for backup sensors, wiring replacements, and supplier price fluctuations |
- ArvaNode
- ₱1,016
- ArvaNet
- ₱3,410
- ArvaCore
- ₱1,529
- Assembly & Deployment
- ₱10,250
- Contingency
- ₱1,795
- Total Estimated Project Expenses
- ₱18,000
- Funding Target
- ₱25,000
- Budget Headroom (Target − Estimated Expenses)
- ₱7,000
Budget headroom is the planned difference between the funding target and the estimated expenses. It is not money already raised; it absorbs price changes once supplier quotations replace the estimates above. Of the total, ₱4,725 uses team-supplied preliminary prices and ₱13,275 is planning estimates.