WitMotion HWT3100-485 Three-Axis Electronic Compass Geomagnetic Sensor for RS485 Modbus RTU (IP67)

Overview

WitMotion HWT3100-485 is a three-axis electronic compass geomagnetic sensor designed for 3-axis geomagnetic intensity measurement and heading angle output. It supports RS485 multi-device connection (up to 50 devices simultaneously) and uses Modbus RTU communication for integration into industrial and embedded systems.

Key Features

• 3-axis magnetic field output and heading angle output
• Portable fluxgate digital gauss meter design
• RS485 multi-device connection: up to 50 multiple connections simultaneously
• High resolution; one-key reset; magnetic auto-recovery
• IP67 protection; high-quality aluminum shell; suitable for harsh environments
• Soaking in water can be up to 30 mins (as stated)
• Easy to read graphs: simple, visual data review in real time; quickly know data changes
• From provided description: selectable measurement range and output rate (0.2-100Hz stated); 32-bit processor; SCA3300 temp-compensation MEMS module; RM3100 magnetometer-compensation chip; dynamic fusion algorithm and Kalman Filtering; angle measurement accuracy 0.05 degree (X, Y-axis), low-drift Z-axis angle, automatic data correction, large signal-noise immunity

Specifications

Name	HWT3100 Fluxgate Sensor
Brand	WitMotion
Model (this listing)	HWT3100-485
Voltage	5V-36V
Current	RS485 version: <10mA (TTL version reference: <6mA)
Protocol	Modbus RTU
Baud rate	9600 (default), 115200, 460800
Communication	Serial TTL / Serial 485
Range	-800uT to +800uT
Sensitivity	13nT/LSB
Data output	0.1Hz-100Hz (TTL), Modbus RTU
Temperature	-40 C to +85 C
Weight	Sensor: 50g; cable (1m, weight: 48g)
Size	83*25*25mm / 3.27*0.99*0.99"
Mounting	2 x M2
Mechanical drawing callouts	83mm length; 25mm body height; 21.5mm (callout); 40mm (callout); 16mm (callout); 16.2mm (callout)

Built-in Sensor Chips

• 2* Sen-XY-f (pn13104) geomagnetic module
• 1* Sen-Z-f (pn13101) geomagnetic module
• 1* MagI2C (pn13156) control chip

Parameter Table (Cycle Counts)

Parameter	50	100	200
Field Measurement Range	-800uT to +800uT
Noise	30nT	20nT	15nT
Gain@3V (LSB/uT)	20nT	38nT	75nT
Linearity over +/-200uT	0.5% (typical)
Sensitivity	50nT	26nT	13nT
Max 3-Axis Sample Rate	534uA	284uA	147uA
Current Usage@8Hz, 3Axes	70uA	135uA	260uA
Circuit Oscillation Frequency	180kHz
Bias Resistor (RB)	121

Interface (Wire Color / PIN Definition)

TTL version interface description (reference)

Color	PIN	Definition
Red	VCC	5-36V power input
Green	RX	Serial data input, TTL level
Yellow	TX	Serial data output, TTL level
Black	GND	Ground wire

485 version interface description

Color	PIN	Definition
Red	VCC	5-36V power input
Green	B	Differential signal 485 communication A
Yellow	A	Differential signal 485 communication B
Black	GND	Ground wire

Data Output Notes

• Supports Modbus RTU raw data output.
• Serial ASCII code output is shown for the serial version; note: the RS485 version does not support the ASCII output mode.

Applications

• Magnet
• Speaker
• Mechanical Part
• Magnetic Separator
• DC
• Iron Remover

Support & Warranty

Warranty: 12-month warranty (as stated). A tutorial link is printed on the guiding card inside the package. For order support, integration questions, or wiring help, contact [email protected] or visit https://voltaspir.com/.

Details

Choose the HWT3100-485 version for RS485 networks using Modbus RTU communication.

The HWT3100-485 measures 3-axis geomagnetic intensity and outputs heading angle for compass and orientation tasks.

An IP67-rated aluminum shell supports use in harsh environments where dust and water exposure are expected.

Suitable for integration into equipment affected by magnetic fields such as motors, separators, and other industrial assemblies.

RS485 multi-drop wiring supports connecting up to 50 sensors on the same bus for scalable deployments.

For HWT3100-485, use Modbus RTU rather than ASCII output mode.

Modbus RTU output makes it straightforward to parse readings in PLCs, gateways, and embedded controllers.

Mechanical dimensions and core specs are provided for enclosure planning, mounting, and system power budgeting.

Wire color definitions help verify power and communications connections before commissioning.

Connection diagrams summarize typical hookups for MCU UART (TTL) and differential RS485 (A/B) installations.

Documentation, PC tools, and sample code support faster setup and integration.