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DIY Gradiometer Kit Firmware Updates

Overview​

The DIY Gradiometer Kit runs firmware on the MAG-BOARD, which controls sensor reading, display output, user interface, and Bluetooth connectivity.

Firmware updates are distributed as precompiled binary files (.bin) and are flashed to the MAG-BOARD using the ESP32 Flash Download Tool via a MicroUSB cable.

Updating the Firmware​

warning

Always note your current firmware version before updating. Updating firmware may reset internal gradiometer configuration parameters.

Requirements:

Steps:

  1. Download the firmware .bin file from the link below
  2. Connect the MAG-BOARD to your PC using the MicroUSB cable
  3. Open the ESP32 Flash Download Tool and select ESP32 as the chip type
  4. Load the firmware .bin file and set the flash address to 0x10000
  5. Select the correct COM port and set the baud rate to 921600
  6. Click START and wait for the upload to complete
  7. Disconnect and reconnect power to apply the new firmware
tip

After flashing, the LCD display should initialize and show sensor readings within a few seconds of power-on.

Version History​

Version 1.3​

Status: Latest release — Download

Improvements:

  • Improved gradiometer gradient calculation stability
  • Enhanced Bluetooth connectivity with the FG Sensors Android app
  • Improved LCD display contrast and readability
  • Optimized sensor reading timing for better measurement accuracy
  • Added NULL button functionality for real-time gradient zeroing

Bug Fixes:

  • Fixed occasional sensor reading freeze after extended operation
  • Resolved display flickering on certain LCD modules
  • Fixed Bluetooth reconnection issue after signal loss

Notes:

  • Compatible with all MAG-BOARD hardware revisions
  • Supports single-sensor and dual-sensor (gradiometer) configurations

Troubleshooting Firmware Updates​

Upload fails or does not start

  • Verify the correct COM port is selected in the Flash Download Tool
  • Ensure the MicroUSB cable supports data transfer (not charge-only)
  • Try a different USB port on your PC
  • Restart the Flash Download Tool and retry

MAG-BOARD does not start after update

  • Disconnect and reconnect power
  • Verify the firmware .bin file is the correct version for the MAG-BOARD
  • Re-flash the firmware using the same procedure

Display blank after update

  • Check the LCD voltage selection jumper matches your display type (5V or 3.3V)
  • Adjust the LCD contrast potentiometer on the board
  • Verify the LCD connector is properly seated

COM port not detected

  • Install the latest USB-to-UART bridge driver (CP210x or CH340 depending on hardware revision)
  • Check Device Manager for driver errors