Project showcase
FoxyPI - Arduino Nano-Based Pulse Metal Detector

FoxyPI - Arduino Nano-Based Pulse Metal Detector © CC BY-NC-SA

Pulse induction metal detector, built on the Arduino Nano.

  • 11,954 views
  • 19 comments
  • 21 respects

Components and supplies

Necessary tools and machines

09507 01
Soldering iron (generic)
Hy gluegun
Hot glue gun (generic)

About this project

FoxyPI - motion/non-motion pulse induction metal detector, built on the Arduino Nano 3.0, with audiovisual indication, setting parameters via the menu, automatic or manual ground balancing.

Appearance:

Circuit:

Firmware:

HEX-file for Arduino Nano 3.0 (version 3.4 from 09/25/2019) - https://acdc.foxylab.com/sites/default/files/FoxyPIv3_4.ino.eightanaloginputs.hex

ELF-file for Arduino Nano 3.0 (version 3.4 from 09/25/2019) - https://acdc.foxylab.com/sites/default/files/FoxyPIv3_4.ino.elf

Operating principle

With a sharp decrease in the current in the search coil, its magnetic flux also decreases sharply. This phenomenon causes the occurrence of eddy currents in the target, penetrated by this magnetic flux. The resulting eddy currents counteract the reduction of the magnetic flux, which is manifested in a change in the voltage curve on the coil and is noticed by the device.

Metal detector operation

The metal detector works in two modes:

  • static mode (non-motion mode) (default) - the signal level is taken into account, does not require constant coil movement (can be used both for pinpointing the target location and the main search mode);
  • dynamic mode (motion mode) - the dynamics of the signal changes is taken into account, during the search the coil must be moved above the ground surface

When a metal target object is detected, a sound signal of varying tonality sounds and LEDs light up. The signal changes in accordance with the dynamics (in dynamic mode) or the level (in static mode) of the received pulse.

When the detector is turned on, auto-balancing is performed. In the process of auto-balancing, the optimal initial delay and duration of the analyzed signal are estimated, and the dynamics of the signal (in dynamic mode) or signal level (in static mode) is evaluated. Also, balancing can be started/stopped during operation by pressing the control button. After the end of the auto-balancing, a short beep sounds and the “zero” value is displayed:

Using the button-controlled menu, you can configure the device parameters:

L - pulse duration (μs)

R - pulse repetition rate (pps)

I - integrator coefficient

F - filter coefficient

S - sound (on / off, ON / OFF)

Detailed Description (in Russian):

https://acdc.foxylab.com/node/47

Tests

The detection range of targets in the "air" test in non-motion (in a motion a little less) mode:

(the test was carried out with the batteries discharged to 1.3 V , therefore, the data are understated)

golden ring (3) - 9 cm;

coin 5 roubles (U.S. quarter analog) (2) - 15 cm;

HDD plate (1) - 33 cm.

Some results of the garden search with FoxyPI (after electrolytic cleaning):

During operation, the device should be located at a distance from working televisions, computers, power transformers, CFLs.

Firmware for testing of FoxyPI v3 (hex-file):

https://acdc.foxylab.com/sites/default/files/FoxyPIv3_TST.ino.eightanaloginputs.hex

In test mode, the metal detector generates a current pulse with a duration of 150 μs in the search coil after switching on, and then it displays the received signal on the screen. Pressing a button generates a new impulse, etc.

Examples of signals:

Videos:

Non-motion mode

Version 3.3, non-motion mode, "air" test

Motion mode

Version 3.3, motion mode, "air" and "underground" tests

Version 3.2, motion mode, "air" test

Schematics

Schematic (version 3)
Foxypi v3 kicad zoom nvy0fyzo7y

Comments

Similar projects you might like

Metal Detector Alert Monitoring System

Project tutorial by shashi shekhar

  • 1,739 views
  • 1 comment
  • 13 respects

Portable Distance Detector

Project tutorial by Viktor S

  • 7,134 views
  • 5 comments
  • 18 respects

Simple Movement Detector

Project showcase by Sriram MN

  • 2,351 views
  • 7 comments
  • 12 respects

The Vibrating Pressure Temperature Altitude Tilt Detector

Project tutorial by Kutluhan Aktar

  • 1,658 views
  • 0 comments
  • 4 respects

Zero Gravity Detector

Project showcase by hminowa

  • 729 views
  • 0 comments
  • 2 respects

Arduino Nano-Based Educational Gear-Pump kit

Project showcase by Team FRBB-MECHELEC

  • 693 views
  • 0 comments
  • 2 respects
Add projectSign up / Login