SE01-MS Soil Moisture and EC Mesh Node

1. Product Overview

SE01-MS is a solar-powered Dragino Mesh Node for monitoring soil moisture, soil temperature, and soil electrical conductivity. It combines one buried soil probe with LoRa Mesh communication, allowing measurements to reach a Mesh gateway directly or through other Mesh Nodes when the gateway is outside the node's direct radio path.

The probe determines volumetric soil moisture by the FDR method and compensates the result using soil temperature and conductivity. It is factory calibrated for mineral soil and is intended especially for saline-alkali and loamy soil. Installation quality and soil conditions remain important because the probe measures the soil volume immediately surrounding its sensing rods.

2. Applications

• Irrigation monitoring in fields, greenhouses, nurseries, orchards, and landscaping projects.
• Root-zone moisture and temperature monitoring for crop management.
• Soil conductivity monitoring for changes related to salinity, fertilizer, and irrigation conditions.
• Remote agricultural sites requiring solar power and multi-hop wireless coverage.

3. Main Features

• Measures soil moisture, soil temperature, and soil conductivity with one integrated probe.
• FDR moisture measurement with temperature and conductivity compensation.
• Temperature-compensated conductivity measurement.
• IP68 soil probe for permanent underground installation.
• LoRa Mesh communication with multi-hop relaying between nodes.
• S-type outdoor enclosure, solar panel, and 3000 mAh rechargeable lithium battery.
• Automatic scheduled measurement, Mesh reporting, and low-power sleep operation.
• Soil measurements, battery information, and device status displayed on the Mesh gateway.
• Firmware upgrade support through USB serial or PC BLE.

4. Enclosure and Probe Reference

For product photos, solar installation reference, enclosure dimensions, and soil probe appearance, refer to the solar-powered version on the SE01-LB/LS product page.

5. Technical Specifications

5.1 Main Unit

Item	Specification
MCU	STM32WLE5, 48 MHz ARM Cortex-M4
Flash	256 KB
RAM	64 KB
Radio	STM32WLE5 integrated sub-GHz LoRa radio
Power supply	Solar panel + 3000 mAh rechargeable lithium battery
Main board operating voltage	Approximately 2.5 V - 3.6 V
Main board operating temperature	-40 °C - 85 °C; battery operating temperature is subject to the battery specification
Local interfaces	3.3 V UART, BLE
Antenna	Sub-GHz LoRa antenna matching the shipping Region

5.2 Soil Probe

Item	Specification
Probe operating voltage	5 V - 24 V
Current while powered	Peak less than 30 mA; average less than 10 mA
Response time	Less than 1 second
Measurement stable time	Less than 2 seconds
Protection rating	IP68
Operating temperature	-40 °C - 85 °C
Approximate measurement volume	Cylinder 7 cm in diameter and 10 cm high, centered on the probe's central pin

5.3 Measurement Performance

Parameter	Range	Resolution	Accuracy	Method
Soil moisture	0 - 100.00 % V/V	0.01 % V/V	±3 % from 0 - 53 % V/V; ±5 % above 53 % V/V	FDR with temperature and conductivity compensation
Soil temperature	-40.00 °C - 85.00 °C	0.01 °C	Less than 0.3 °C from -10 °C - 50 °C; less than 0.6 °C outside this range	Calibrated RTD measurement
Soil conductivity	0 - 20000 µS/cm at 25 °C	1 µS/cm	2 % FS	Conductivity measurement with temperature compensation

6. Understanding the Soil Measurements

The three readings describe different properties of the same soil volume and should be interpreted together. Moisture affects the movement of ions through the soil, so a conductivity change may be related to water content as well as salinity or fertilizer conditions.

Reading	What it represents	Practical interpretation
Soil moisture	Volumetric water content around the sensing rods	Used to observe drying and wetting cycles and support irrigation decisions
Soil temperature	Temperature of the soil around the probe	Useful for root-zone and seasonal soil monitoring
Soil conductivity	Overall electrical conductivity of soluble ions around the probe	Indicates changes in the ionic condition of the measured soil volume; it does not identify individual nutrients

The approximate sensing volume is a cylinder 7 cm in diameter and 10 cm high around the central pin. Rocks, large roots, buried metal, or air gaps within this area can make the reading less representative of the surrounding soil.

The standard calibration is for mineral soil, especially saline-alkali and loamy soil. For other soils or growing media, compare the installed probe with a suitable local reference before defining project thresholds.

7. Soil Probe Installation

Correct installation means placing the probe at the intended measurement depth while preserving firm, continuous contact between the sensing rods and the soil. Do not hammer, bend, twist, or force the probe against rocks or other hard objects.

7.1 Selecting the Measurement Point

Choose a position that represents the area being monitored. Avoid placing the probe directly beside an irrigation outlet, fertilizer deposit, drainage channel, large root, pipe, or buried metal unless that specific condition is the intended subject of the measurement.

For comparisons between sites, use the same installation depth and method. Differences in soil layer, compaction, and water distribution can otherwise be larger than the differences caused by the monitored treatment.

7.2 Temporary Measurement

Use vertical insertion for spot measurements or site comparison.

Open soil to the target depth
            ↓
Insert the probe vertically and steadily
            ↓
Restore firm soil contact around all rods
            ↓
Allow the reading to stabilize

Preserve the original soil density as much as possible and do not shake the probe during insertion.

7.3 Permanent Installation

Use horizontal insertion into an undisturbed soil wall for long-term monitoring.

Dig an access hole larger than 20 cm
            ↓
Insert the probe horizontally at the required depth
            ↓
Remove air gaps around the sensing rods
            ↓
Backfill the hole and restore the soil density

Route the probe cable without tension or sharp bends. Install the enclosure above ground with the cable outlet facing downward and provide a drip loop so water does not run toward the enclosure connection.

7.4 Installation Check

After installation, trigger a new report and confirm that moisture, temperature, and conductivity values appear on the Mesh gateway. Abnormally low, fixed, or unstable values usually indicate poor soil contact, an unsuitable measurement point, or a probe connection problem.

8. Data on the Mesh Gateway

After enrollment and a completed measurement cycle, the Mesh gateway presents the current soil measurements together with the node condition:

• Soil moisture in % V/V.
• Soil temperature in °C.
• Soil conductivity in µS/cm.
• Battery level or battery status.
• Device online status and data update time.

The gateway displays decoded values; the user does not need to parse a raw sensor frame. Display names and page layout depend on the Mesh gateway version.

9. Normal Operation

After enrollment, SE01-MS follows the configured reporting schedule:

Wake up -> Power and read the soil probe -> Send measurements to the Mesh gateway -> Enter low-power sleep

To request an immediate update, first wake the device if it is sleeping. While it is active, hold the button and release it within 1 to 3 seconds. The new values are sent after the probe measurement cycle is complete.

10. Quick Start

10.1 Installation and First Report

1. Confirm that the product label shows SE01-MS and that the device and antenna Region match the deployment location.
2. Install the LoRa antenna before powering on the node, then place the solar panel where it receives stable, unobstructed sunlight.
3. Enroll the node and trigger a report before burying the probe. Confirm that moisture, temperature, and conductivity appear on the Mesh gateway.
4. Select the measurement point and depth, then install the probe using the temporary or permanent method in Section 7.
5. Secure the enclosure above ground, keep the cable outlet facing downward, and protect the cable from pulling, crushing, and sharp bends.
6. Trigger another report after installation and confirm that the readings are plausible for the site conditions.

10.2 Initial Enrollment

For complete instructions, see Quick start — 2. First network test.

11. Power Consumption and Solar Power

Battery performance depends on the reporting interval, Mesh coverage, relay conditions, sunlight, solar-panel orientation, ambient temperature, and battery condition. Short reporting intervals increase the number of probe power-up and radio-transmission cycles.

Install the solar panel for the site's worst seasonal sunlight conditions, not only for the conditions present during commissioning. Keep the panel free of dust, leaves, and shading. If the battery level continues to fall, check the panel connection, exposure to sunlight, reporting interval, Mesh path, and ambient temperature.

12. Use and Maintenance

Inspect the installation periodically and after field work, irrigation-system changes, or soil excavation near the probe.

• Keep the solar panel clean and unobstructed.
• Check the antenna, enclosure mounting, waterproof connectors, cable, and drip loop.
• Do not pull the probe by its cable. Loosen the surrounding soil before removing a buried probe.
• Remove heavy soil deposits with clean water and a soft cloth or brush; do not direct a high-pressure water jet at the cable entry or connector.
• After moving or reinstalling the probe, verify soil contact and trigger a new report before comparing the result with earlier data.

13. Troubleshooting

Issue	Check and corrective action
The Mesh gateway cannot find the node	Confirm the Region, antenna installation, gateway status, battery level, and node wake state
The node is enrolled but no soil values appear	Check the probe connection, wake the node, and trigger a manual report; allow the measurement cycle to finish
Moisture remains near zero	Check that all sensing rods are surrounded by soil and that there are no air gaps, rocks, or a disconnected probe
Moisture is fixed or changes abruptly	Inspect soil contact, recent soil disturbance, irrigation directly beside the probe, and the probe cable connection
Soil temperature does not represent the target depth	Confirm that the sensing area is installed at the intended depth and is not exposed to surface heating
Conductivity is unexpectedly low	Check probe contact and soil moisture; very dry soil can produce low conductivity readings
Conductivity is unexpectedly high	Check for saturated soil, recent fertilizer application, saline irrigation water, or contamination on the sensing rods
Measurements differ from another instrument	Compare both instruments at the same depth and in the same soil volume, allowing both readings to stabilize
Battery level continues to fall	Check sunlight, panel cleanliness, cable connection, reporting interval, Mesh coverage, and ambient temperature
Soil values disappear after a firmware upgrade	Confirm that the installed firmware matches SE01-MS and the shipping Region, then trigger a new report