WitMotion JY-RM3100 Serial 3-Axis Electronic Compass Module (PNI RM3100) Heading Angle TTL/SPI/IIC

Overview

The WitMotion JY-RM3100 is a serial 3-axis electronic compass (geomagnetic sensor) module based on a PNI RM3100 magnetic sensor solution, designed to output 3-axis magnetic field data and a heading angle. It uses fluxgate technology and supports multiple interfaces for integration into robotics, UAV/RC navigation, and other heading/attitude sensing projects.

Key Features

• High sensitivity 3-axis magnetic field measurement with heading angle output
• Fluxgate technology
• Multiple interfaces: TTL / SPI / IIC
• Magnetic field self-recovery
• Stamp-hole (castellated) package style ("half hole of stamp hole")
• Built-in MCU for data acquisition (module feature)
• AT serial port support (module feature)
• Heading angle calculation (module feature)
• Magnetic field zero-bias calibration (module feature)

Specifications

Model Parameter Table (as provided)

Parameter	QMC5883L	JY-RM3100	RM3100 (No software)
Operating voltage (current)	3.3-5V (<5mA)	3.3-5V (<6mA)	3.3-5V (<6mA)
Output data	3-axis mag, heading angle	3-axis mag, heading angle	3-axis mag
Range	±8 Gauss	±800uT	±800uT
Return frequency	0.1-100Hz	1-100Hz	0.1-100Hz
Communication method	TTL/SPI/IIC	TTL/SPI/IIC	SPI
Baud rate	9600 (default); 115200, 460800	9600 (default); 115200, 460800	9600 (default); 115200, 460800
Sensitivity	3000 LSB/Gauss	13nT/LSB	13nT/LSB
Operating temperature	-40 to 85°C	-40 to 85°C	-40 to 85°C
Mode	ASCII/Modbus/Modbus Auto output	ASCII/Modbus	\

RM3100 Performance Parameters (Cycle Counts 50 / 100 / 200)

Parameter name	50	100	200	Unit
Measurement range	-800~+800	-800~+800	-800~+800	uT
Gain	20	38	75	LSB/uT
Sensitivity	50	26	13	nT
Noise	30	20	15	nT
Noise density	1.2			nT/Hz
Repeatability > ±200uT	15	8	8	nT
Hysteresis > ±200uT	15			nT
Linearity > ±200uT	0.5			%
Single axis sampling rate	1600	850	440	Hz
Single axis average current	70	150	260	uA
Bias resistance	121
Operating temperature	-40~85

RM3100 Magnetic Kit Main Basic Parameters

3-axis sampling rate	550Hz
Interface	SPI & I2C
Dimensions (length x width x height) - MagI2C	4.0 x 4.0 x 0.75mm
Dimensions (length x width x height) - Sen-XY	6.0 x 2.1 x 2.2mm
Dimensions (length x width x height) - Sen-Zv	3.0 x 3.0 x 5.75mm

Additional Text Specs Shown

• RM3100 SPI measurement range: ±800uT
• JY-RM3100 measurement range: ±800uT
• QMC5883L measurement range: ±8 Gauss
• Measurement noisy is less than 15uT @ 200 Cycle Count
• Measurement resolution is higher than 13uT @ 200 Cycle Count

Dimensions

JY-RM3100 Module Dimensions (as shown)

• 15.24mm x 15.24mm
• 12.7mm (shown on drawing)
• 2.54mm (shown on drawing)
• 0.9mm (shown on drawing)
• Thickness: 7.35mm

RM3100 Module Dimensions (as shown)

• Size: 12.7mm x 12.7mm
• Thickness: 7.4mm
• Additional marked dimensions: 2.45mm, 2.63mm, 2.40mm, 2.68mm, 2.54mm, 7.62mm

QMC5883L Module Dimensions (as shown)

• 15.24mm x 15.24mm
• 12.7mm (shown on drawing)
• 2.54mm (shown on drawing)
• 0.9mm (shown on drawing)
• Thickness: 2mm

Wiring / Pinout

JY-RM3100 Pin Names and Functions

Name	Function
INT	Data status, connect chip DRDY pin
VCC	Module power, 3.3V or 5V input
RX	Serial data input, TTL level
TX	Serial data output, TTL level
GND	Ground line
SWIM	Chip SWIM pin
SA1/MISO	1 bit of IIC slave address / SPI master input, slave output
SCL/SCLK	IIC clock line / SPI clock signal line
SDA/MOSI	IIC data line / SPI master output, slave input
SA0/SSN	0 bit of IIC slave address / SPI active low select port

QMC5883L Pin Names and Functions

Name	Function
VCC	Module power supply, 3.3V or 5V input
RX	Serial data input, TTL level
TX	Serial data output, TTL level
GND	GND ground line
SCL	I2C clock line
SDA	I2C data line
D0	D0 connects to MCU's PD4
SWCLK	SWCLK connects to MCU's SWCLK
DRDY	Connects to MCU's DRDY
D3	Connects to MCU's PA3

RM3100 Module Pad Labels (as shown)

• VCC, GND, GND, DRDY
• CLK, MISO, MOSI, SSN

Demo / Data Display

• Serial communication; PC software displays the data in real time.
• Displayed fields include: Magnetic X, Magnetic Y, Magnetic Z, Yaw.

Notes

• RM3100 magnetic sensor kit composition (as provided): 2 x Sen-XY-f (pn13104), 1 x Sen-Z-f (pn13101), and MagI2C (pn13156) control chip, for 3D magnetic field measurement.
• Performance comparison data shown (Hall sensor vs PNI magnetic sensor): Sensitivity 300nT vs 13nT; Noise 500nT vs 15nT; Power consumption current (8Hz, 3 axes) 280uA vs 70uA.
• For selection/compatibility questions (JY-RM-3100 or RM3100 option) and integration support, contact [email protected] or visit https://voltaspir.com/.

Details

The JY-RM3100 module uses a PNI RM3100 fluxgate magnetic sensor to output 3-axis magnetic field data and a calculated heading angle.

Real-time serial output makes it easy to verify Magnetic X/Y/Z readings and yaw on a computer during setup and calibration.

A quick parameter comparison highlights measurement range, update frequency, and interface options across common compass solutions.

Clear pin labeling helps map power, UART, and I2C connections when integrating the module into a controller or dev board.

Castellated “stamp-hole” edges and multi-interface pinout simplify soldering and integration for TTL, SPI, or I2C builds.

Mechanical dimensions and labeled pads support fast PCB layout for RM3100-based designs.

Fluxgate sensing and a standard SPI interface make RM3100 modules a strong fit for robotics, UAV, and navigation projects.

A side-by-side comparison calls out the lower noise and lower current draw advantages of the PNI magnetic sensor approach.

Choosing the full module adds onboard acquisition and serial features, including heading-angle calculation and zero-bias calibration support.

Basic USB‑TTL wiring (VCC, GND, and crossed TX/RX) enables quick PC testing before integrating with a flight controller or MCU.

An optional evaluation setup with onboard USB driver supports plug-and-play testing for rapid prototyping.

The RM3100 compass module uses a simple pin header layout with labeled power and SPI signal pins to simplify MCU wiring.

The JY-RM3100 compass module outputs Magnetic X, Magnetic Y, Magnetic Z, and yaw data in ASCII (AT command) mode for serial parsing.

A 3-axis electronic compass module can be integrated into navigation systems, parking solutions, security access control, and medical equipment.

The development kit includes a manual, Windows software (JY-RM3100), and an SDK to help with setup and integration.

The package includes a QMC5883L module with front/back layout and multiple pin headers for soldering to your project.

The JY-RM3100 compass module includes separate pin headers and clearly labeled pads for wiring power, data lines, and interrupt.