SE0X-MS Multi-Probe Soil Moisture and EC Mesh Node

1. Product Overview

SE0X-MS is a solar-powered Dragino Mesh Node for monitoring soil conditions at several depths or locations from one device. It supports up to four external probes, and each probe measures soil moisture, soil temperature, and soil electrical conductivity.

Every probe is identified by an address from 01 to 04. The node reads the connected probes and sends their measurements to a Mesh gateway through a LoRa Mesh network. Communication can be direct or relayed through other Mesh Nodes when the installation is outside the gateway's direct radio range.

The soil probes use the FDR method for moisture measurement, with compensation from soil temperature and conductivity. They are factory calibrated for mineral soil and are intended especially for saline-alkali and loamy soil.

2. Applications

• Multi-depth monitoring through the crop root zone.
• Comparison of several field zones using one Mesh Node.
• Irrigation monitoring in greenhouses, orchards, nurseries, landscaping, and open fields.
• Distributed soil temperature and conductivity monitoring at remote solar-powered sites.

3. Main Features

• Supports up to four external soil probes.
• Measures moisture, temperature, and conductivity at each probe position.
• Uses addresses 01 to 04 to keep probe data separated.
• Approximately 3.5 m cable length for each probe.
• LoRa Mesh communication with multi-hop relaying.
• S-type outdoor enclosure, solar panel, and 3000 mAh rechargeable lithium battery.
• Automatic scheduled collection of connected-probe measurements.
• Probe data, 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, soil probe dimensions, sensor cable reference, and multi-probe connection examples, refer to the SE0X-LB 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 Multi-Probe System

Item	Specification
Maximum number of probes	4
Supported addresses	01, 02, 03, and 04
Factory-default probe address	01
Measurements per probe	Soil moisture, soil temperature, and soil conductivity
Probe cable length	3500 mm, deviation ±30 mm
Probe protection rating	IP68
Approximate measurement volume per probe	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. Multi-Probe Organization

The probe address is the permanent identity used to associate a measurement with a physical location. Two probes on the same node must not share an address because their responses would conflict.

SE0X-MS
   ├── Probe 01 -> Moisture + Temperature + Conductivity
   ├── Probe 02 -> Moisture + Temperature + Conductivity
   ├── Probe 03 -> Moisture + Temperature + Conductivity
   └── Probe 04 -> Moisture + Temperature + Conductivity

6.1 Preparing Probe Addresses

New probes use address 01 by default. Prepare and verify probes individually before connecting the full group:

First probe  : keep address 01
Second probe : assign address 02
Third probe  : assign address 03
Fourth probe : assign address 04

Connect one probe at a time during address preparation. After every probe has a unique address, reconnect the required group and confirm that each address appears separately on the Mesh gateway before burial.

6.2 Recording the Installation Plan

Label every cable with its probe address and record what the address represents. The address can identify a different depth at one location or the same depth in different zones.

Example: one location, several depths

01 = Root zone, 20 cm
02 = Root zone, 40 cm
03 = Root zone, 60 cm
04 = Deep reference, 80 cm

Example: several locations at one depth

01 = Zone A, 30 cm
02 = Zone B, 30 cm
03 = Zone C, 30 cm
04 = Zone D, 30 cm

Keep this address-to-location record with the site documentation. Without it, gateway values cannot be reliably matched to the buried probe positions.

7. Measurement Planning and Probe Installation

Each probe measures the soil volume immediately surrounding its rods. For meaningful comparison, keep the installation method consistent and change only the variable the project intends to study, such as depth or field zone.

7.1 Interpreting Measurements Across Probes

Moisture, temperature, and conductivity should be considered together. A conductivity difference between two probes may result from different salinity or fertilizer conditions, but it can also be influenced by moisture distribution and soil composition. Conductivity does not identify individual nutrients.

When comparing depths, changes may reflect real soil-layer differences. When comparing locations, use the same depth and similar installation quality so that differences are not caused mainly by probe placement.

7.2 Selecting Probe Positions

Avoid rocks, large roots, pipes, buried metal, and empty spaces within the approximate sensing volume. Do not place a probe directly beside an irrigation outlet, drainage channel, or fertilizer deposit unless that local condition is intentionally being monitored.

The 3.5 m probe cable determines the practical distance between the enclosure and each measurement point. Plan cable routing before burial and avoid tension, crushing, sharp bends, and areas where machinery can damage the cable.

7.3 Temporary Measurement

For spot checks, open the soil to the target depth and insert the probe vertically. Preserve the original soil density, insert the probe steadily without shaking, and restore firm contact around all rods before taking the reading.

7.4 Permanent Installation

For long-term monitoring, dig an access hole larger than 20 cm and insert the probe horizontally into an undisturbed sidewall at the planned depth. Remove air gaps, backfill the hole, and restore the soil density as closely as possible.

Install the enclosure above ground with the cable outlet facing downward. Protect the cable connections and provide a drip loop so water does not run toward the enclosure.

Power Consumption

Battery performance depends on the reporting interval, number of connected probes, Mesh coverage, relay conditions, sunlight, solar-panel orientation, ambient temperature, and battery condition. Reading more probes extends the measurement activity performed during each scheduled cycle.

8. Data on the Mesh Gateway

The gateway groups measurements by probe address, allowing each buried position to be monitored separately:

Probe 01 : Soil moisture | Soil temperature | Soil conductivity
Probe 02 : Soil moisture | Soil temperature | Soil conductivity
Probe 03 : Soil moisture | Soil temperature | Soil conductivity
Probe 04 : Soil moisture | Soil temperature | Soil conductivity
Node     : Battery status | Online status | Data update time

Only connected and successfully read probes produce measurement data. Display names, units, and page layout depend on the Mesh gateway version.

9. Normal Operation

After enrollment, SE0X-MS follows the configured reporting schedule:

Wake up -> Read the connected probe addresses -> Send grouped 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 node sends the new values after the connected-probe measurement cycle is complete.

10. Quick Start

10.1 Prepare, Verify, and Install

1. Confirm that the product label shows SE0X-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. Prepare the required probes one at a time so that every connected probe has a unique address from 01 to 04.
4. Label the cables and record the location and depth assigned to each address.
5. Connect the probes, enroll the node, and trigger a report before burial. Confirm that every expected address appears on the Mesh gateway.
6. Install each probe according to the plan in Section 7, then secure the enclosure and outdoor cable connections.
7. Trigger another report after installation and compare the gateway fields with the address-to-location record.

10.2 Initial Enrollment

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

11. Use and Maintenance

Maintain both the physical installation and the address record. A technically correct reading is not useful when the address can no longer be matched to the buried location.

• Inspect the solar panel, antenna, enclosure mounting, waterproof connectors, and all probe cables.
• Check that cable labels remain readable and that the address-to-location record matches the gateway fields.
• After moving or replacing a probe, verify its address before reconnecting the complete group.
• After excavation or soil disturbance, restore firm contact around the sensing rods and trigger a new report.
• Clean 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.

12. 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
No probe measurements appear	Check the common probe connection, wake the node, and trigger a manual report; allow the complete measurement cycle to finish
Only some probe addresses appear	Check the missing probe cable and confirm that its address is within 01 to 04 and is not duplicated
Two probes conflict or appear under the same field	Disconnect the group and verify the probes individually; assign a unique address to each probe before reconnecting them
A newly added probe conflicts with Probe 01	New probes use address 01 by default; prepare the new probe with an unused address before connecting it to the group
A probe reports fixed, zero, or unstable moisture	Check soil contact, air gaps, rocks, cable damage, and the physical installation of that probe address
Conductivity differs strongly between probes	Compare moisture, depth, soil type, fertilizer history, and installation position before treating the difference as a sensor fault
Gateway fields do not match the expected locations	Compare the cable labels and address-to-location record; verify probes individually when the mapping is uncertain
Battery level continues to fall	Check sunlight, panel cleanliness, cable connections, reporting interval, number of probes, Mesh coverage, and ambient temperature
Probe data disappear after a firmware upgrade	Confirm that the installed firmware matches SE0X-MS and the shipping Region, then wake the node and trigger a new report