Integration Overview
This section covers everything needed to integrate FG Sensors products into your measurement system — from hardware wiring and signal conditioning to serial communication, software libraries, and complete system architectures.
What Is Covered
| Section | Description |
|---|---|
| Hardware | Wiring, signal conditioning, board integration |
| Software | Serial formats, Arduino and Python code |
| System Architectures | End-to-end diagrams and architecture selection guide |
Main Integration Paths
FG-3+ and FG-4 — Frequency Output to Microcontroller
The FG-3+ and FG-4 output a 5 V PWM whose period is proportional to the measured magnetic field strength. Integration is straightforward with any microcontroller that supports frequency or period counting.
Typical path:
FG-3+ / FG-4 → MCU digital input (timer/counter) → period measurement → field value in nT
- No analog frontend required
- Resistant to cable noise
- Suitable for Arduino, ESP32, STM32, and similar platforms
- The Converter Circuit Board converts the frequency signal to an analog voltage if an ADC or DAQ interface is preferred
FG-3C — UART, Analog, and PWM Integration
The FG-3C is a 1-axis fluxgate magnetometer with multiple output modes selectable by pin configuration:
- UART at 115200 baud — outputs field values as text in nT
- Analog voltage — proportional to field, suitable for ADC input
- PWM — duty-cycle-encoded output
Typical path:
FG-3C → UART RX pin on MCU or USB-UART bridge → text parsing in software
The UART mode is the simplest path for direct digital integration without any signal conditioning hardware.
FGA Logger — SD Logging, GPS, UART, and USB
The FGA Logger is a complete standalone data acquisition unit for 3-axis magnetic field measurements. It handles sensor reading, GPS timestamping, and logging internally — requiring no external MCU.
Typical path:
Bartington UB 100 MAG-649 → FGA Logger → SD card (CSV) / USB serial / DB9 UART → analysis software
- Up to 2 × 3-axis sensor inputs
- CSV format with magnetic field, GPS coordinates, and fix quality
- Serial output at configurable baud rate
- Compatible with PolarWave DATA, QGIS, Python, and MATLAB
Choosing an Integration Path
| Use Case | Recommended Path |
|---|---|
| Custom embedded system | FG-3+ / FG-4 → MCU with frequency counting |
| Analog input (DAQ, PLC, oscilloscope) | FG-3+ → Converter Circuit Board → ADC |
| Simple serial data stream | FG-3C in UART mode → MCU or PC |
| Field survey, GPS-tagged logging | FGA Logger → SD card or USB |
| DIY gradiometer with display | MAG-BOARD with FG-3+ sensors |
Notes on Signal Levels
All FG Sensors sensors require a regulated, clean DC supply. Avoid powering sensors from unregulated sources or sharing a supply rail with motors or switching converters without adequate filtering.
FG-3+ and FG-4 output a 5 V logic signal. If connecting to a 3.3 V microcontroller, use a level shifter or voltage divider to protect the MCU input.