FoxyPI - Arduino Nano-Based Pulse Metal Detector

Pulse induction metal detector, built on the Arduino Nano.

Apr 14, 2019

61695 views

31 respects

Components and supplies

2

BC547

1

General Purpose Dual Op-Amp

1

Arduino Nano R3

1

IRF840

1

BC557

1

LM385Z-1.2

Tools and machines

1

Soldering iron (generic)

1

Hot glue gun (generic)

Project description

Downloadable files

Schematic (version 3)

Schematic (version 3)

Comments

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hoomandelfani00

5 months ago

Hi dear friend , thank you for this project , could you please send me the Arduino file ? my whats App number : 00989122591527

hoomandelfani00

5 months ago

Hi friend , I need the Arduino code , could you please send me that ? my email address is : hooman1006@yahoo.com my whats App / Telegram : 00989122591527 thank you

hoomandelfani00

5 months ago

Hi friend , I need the Arduino code , could you please send me that ? my email address is : hooman1006@yahoo.com my whats App / Telegram : 00989122591527 thank you

milespeterson101

a year ago

Ridiculous unneeded components! You don't need transistors, and you don't need voltage regulators! You could make the circuit much more simple by having the Arduino doing most of the work!

FoxyLab

a year ago

Air tests of DIY pulse (Arduino Nano based) metal detector FoxyPI https://youtu.be/x4ZGx5oOfHk Detection ranges: coin 3 kopecks USSR 1979 - 23-24 centimeters, hard disk platter - 34-36 centimeters

Anonymous user

2 years ago

Alexey. Thank for sharing this valuable circuit with us. I have a question. i need your help in my project. i want to design a metal detector which can sense tiny (like 1 inch Nail) moving particle . let suppose the speed of the the particle will be 22 meter per minute. i will be thankful to you. can you help me in this matter. Thanks in Advance

FoxyLab

2 years ago

Thanks! To reduce the reaction time, it is necessary to increase the pulse repetition rate in the detector coil.

Anonymous user

2 years ago

Hello Alexey! I have made your project. It works good. I also made a PCB with SMD Parts.The PCB for the display can be separated. Here is no way to show it. I also have made a Version from your first Detector which works with one Voltage Source. It works also good. The Display ist not the best Solution. There are many Oled Displays which are not so sensitive. You have made a good and interesting Work!

FoxyLab

2 years ago

Thanks!!! It's great that everything worked out! I plan to make support for other displays, moreover, the type of display will be selected by jumpers. I have experience using the OLED display in my bike computer (https://acdc.foxylab.com/velo). Here https://www.geotech1.com/forums/showthread.php?17931-Arduino-metal-detector/page7, enthusiasts also design circuit boards for FoxyPI.

FoxyLab

2 years ago

Video illustration of starting procedures: https://youtu.be/6YwlmcuxyKs

Anonymous user

2 years ago

I know this is old project but can u provide the source code for the latest version of firmware ? I am trying to build my own metal detector your code could help me understand different aspects better. if u are willing to provide source code my email address is hzaib76@gmail.com.

Anonymous user

2 years ago

Hallo Alexey. First thanks for this tutorial. I decided to have some fun and build this metal detector... Want to make a small PCB, but having some questions... 1) Where i can find latest schematics? 2) How does L2 coil looks like ? can you share photo, specs etc. 3) i know you don't want to share INO code but do you accept suggestions for upgrades? 4) any possibilities to add headphones output? I'm not electronic specialist but I'm handy with my 3d printer so when i get my PCB done i want also to add 3d printed case and search coil.

Anonymous user

2 years ago

Hello Sir i am Ananda from sri lanka please let me send V 5 arduino code. info.ecojump@gmail.com Thanks.

FoxyLab

2 years ago

Hello! HEX and ELF files only, its closed source project.

Anonymous user

2 years ago

Nice. What is the value of L1 and L2? L2 looks like a filter for the power supply, but L1, the search coil has no description, or I'm just blind today. I would assume 0.4mm wire 25-30 turns around a 20cm diameter form. Could you tell me if that is right? Thanks.

FoxyLab

2 years ago

Thanks! Yes, L2 - filter coil. My L1 coil - diameter 25 cm , 0.7 mm (diameter) wire, 27 turns.

Anonymous user

2 years ago

Nice project, but without the source code, I'm not building it. Make this an open source project and let others improve on it.

FoxyLab

2 years ago

I respect your opinion, but the status of the project will not change.

Anonymous user

2 years ago

WE make this but isnt work.May be have a some mistakes.Can u help me.Can u send me arduino code for version 2 aaset355@gmail.com.PLS

FoxyLab

2 years ago

It is easier for me to answer here, and similar questions may arise from other people who wanted to make this device.

FoxyLab

2 years ago

Describe what is not working for you. I'll do a test sketch the other day.

FoxyLab

2 years ago

Wait for the zero level update to complete (the metal detector stops beeping) and briefly (shorter than two seconds) press the button to complete the balancing and switch to the search mode.

Anonymous user

2 years ago

apakah anda bersedia mengirimkan file.ino nya? saya mau mempelajarinya, kalau file HEX, saya bingung

Anonymous user

2 years ago

THANKS for reply. I make this.But We only see "zeroning" else nothing.Why?.I need a your help

Anonymous user

2 years ago

We Can chatting on Gmail.Can u write me

Anonymous user

2 years ago

Hi, Very nice project, I wanted to build something similar in the past. Now I feel, I will follow your tutorial and experience. But I found some mistake in the circuit diagram, I think you have a Bat1-Ground short circuit. You have to cut the line between the two protecting diode. (VD1 and VD2) Anyway, it's a good design! :)

FoxyLab

2 years ago

Very thanks!!! About grounds - Its typical question ;-) My circuit has two ground - digital ground (chassis (?, my english is bad) symbol) and power ground (grounding symbol) and two batteries - Bat1 - for power, Bat2 - for digital. Pleased to answer your questions

FoxyLab

2 years ago

P.S. I remind you that in the scheme two grounds are not interconnected

FoxyLab

2 years ago

No, why? See my reply above.

Anonymous user

2 years ago

Hi,İ have one question.We must cut the line between vd1 and vd2

Anonymous user

2 years ago

Amigo Alexy, Entiendo que los detectores por Induccion de Pulso NO necesitan el modo balance de tierra, esto es cierto del todo? y si fuese un detector VLF cual deberia ser el metodo de Balance manual o automatico mas efectivo, por hardware o software?. Tienes alguna informacion que pueda ayudarme? . mi correo es vextorst@gmail.com. mi WS: +584124160819

FoxyLab

2 years ago

¡Buenas tardes! El equilibrio es necesario, pero no es tan crítico como para los detectores VLF. Cuando enciendo mi detector, se realiza el autoequilibrado (también se puede reiniciar presionando un botón si las propiedades del suelo han cambiado mucho). Desafortunadamente, no tengo buenas habilidades prácticas en el campo de los VLF detectores para darle un consejo definitivo.

Anonymous user

2 years ago

Does this use magnets, as I can't use magnets

FoxyLab

2 years ago

No, this device doesn't use magnets, but coil generates magnet field, yes.

Anonymous user

2 years ago

Hello! I built your metal detector with a loaded v3.4 version on an Arduino Nano. All great, but it's barely visible on the display (too little contrast). I'm using the LCD from here: https://www.aliexpress.com/item/32729495509.html?spm=a2g0s.9042311.0.0.3da24c4dDGAzID I tried your first version (https://github.com/Dreamy16101976/foxyPIv1/blob/master/FoxyPIv1.ino) and had to increase the value in line 63 from "const byte CONTRAST = 50; // LCD contrast" to "const byte CONTRAST = 60; // LCD contrast "so I could read normally from the LCD. Considering that version 3.4 is not GNU, is it possible to get HEX-corrected gain or just what location to fix in HEX for the correct contrast on my LCD. Greetings Alojz R.

FoxyLab

2 years ago

Hello! Thanks for report! I’ll do it easier - I’ll add a contrast setting to the menu. Best regards Alexey P.S. Your module is "red" LCD module, but i used "blue". What is your LCD VCC (supply voltage) - 5 V or 3.3 V?

FoxyLab

2 years ago

Yes, contrast set to default (50) from power-on to settings reading from EEPROM.

FoxyLab

2 years ago

Ready (see comment below)!

FoxyLab

2 years ago

The project was carried out using a hinged installation. PCB not exists.

Anonymous user

2 years ago

please,they would be gerber data?

Anonymous user

2 years ago

Yes, my LCD is red. The enclosed instructions state that Vcc may also be 5V. I tried with Vcc 5V and 3.3V but the contrast does not change. Of course, setting the contrast in the menu is the best solution. Please let me know when there is a new version with a new menu. Thanks for the quick reply and best regards. Alojz R.

Anonymous user

2 years ago

Great! Now I can adjust the display to the right contrast. The downside is that the power-on contrast is not set yet. So when the countdown ends and the image disappears, the contrast is set correctly. Otherwise it doesn't bother me too much. Thanks again for the quick fix. Alojz R.

FoxyLab

2 years ago

Minor update ( version 3.8 ) is ready: improved display of signal curves in test mode (through earlier reading of preset settings, including contrast).

Anonymous user

2 years ago

can you help sir please no ino file how can load with ide nano? thanks

FoxyLab

2 years ago

Influence of the value of the GUARD parameter on the detection range of the golden ring (L): GUARD L, cm 500 ---> 12 750 ---> 10 1000 ---> 8 1500 ---> 7 It is possible to decrease it even below 500, but in this case false positives may appear.

FoxyLab

2 years ago

I decided to numerically evaluate the stability of my metal detector - it turned out to be quite satisfactory: after 15 minutes of operation, the detection range of targets decreases by less than 4%.

FoxyLab

2 years ago

The FoxyPI firmware version 3.5 is ready. What's new: added the ability to adjust the display contrast using the CONTRAST item in the service menu

FoxyLab

2 years ago

FoxyPI firmware v3.6 is ready! What's new in version 3.6: + added the ability to configure the guard interval using the GUARD item of the service menu; + added auto-tuning of levels 1 and 2 of the audiovisual indication in static mode; + integrated test mode (to activate, after switching on, hold the control button until the graph of the signal curve appears)

FoxyLab

2 years ago

FoxyPI firmware v3.7 is ready! What's new in version 3.7: * small code optimization was performed to increase the stability of the metal detector + beep indication for errors ERR 01 and ERR 02 added

FoxyLab

2 years ago

The final firmware version 3.4 is ready! What's new: MOSFET overheating is excluded increased stability added auto-tuning interval between ADC samples added display of the signal curve after auto-balancing

Anonymous user

2 years ago

I Built it, And i got it working. first Test the MOSFET got extremly hot, next time Test its working, and i tryed to adjust Frequency and Pulselenght, then the MOSFET burned. May be there is something wrong in the Circuit in front of the MOSFET, or so?

Anonymous user

2 years ago

now its Working with an IRF710 MOSFET I connected the Display light wrong, (on Plus not on GND as it should) and somehow it burned the FET i used ~31 windings of 0,5mm chopper wire, and it works great.

Anonymous user

2 years ago

Thank you Alexey for this project. I am oufbuzz, living half in Africa and half in France. I would like to realize it, but as Mamaev found two years ago, I also think there will be a short circuit on the Bat1 battery. I have been following all your discussions about this, but I am not aware of the end. Where can we find the latest version of this project? Would it be possible to have the source code of the .HEX file version 3.8. Is there a PCB to make it available? Many thanks for this project.

Anonymous user

2 years ago

Thank you for your explanations and directions. I have started the assembly. I hope that it will work well as with the others. My concern would be to change on demand the frequency, which to change sometimes also L2. Is this possible? My needs are mainly oriented in the search for gold. Since the source code is closed, thank you for publishing the project, can we transfer the detection indications, on a small arduino screen in the form of a bar graph, at the same time as the indications audible by the buzzer. That would be great. I have already seen it in other arduino projects. It would be very interesting for me to add a discriminator to distinguish ferrous metals from non-ferrous. I am sure you have already thought about this problem. Do you have a solution? M Thank you for this project and the answers you can give me. Translated with www.DeepL.com/Translator (free version)

FoxyLab

2 years ago

Hello from Belarus! If you look closely at the circuit of my metal detector, you will notice that there are two grounds in the circuit - GNDA & GNDD, indicated by different icons and not connected to each other ;-) Therefore, there is no short circuit in the circuit. And accordingly, there can be no discussion on this topic :-) Main page - https://acdc.foxylab.com/node/47 (on russian, use Google Translate). On english - https://hackaday.io/project/167704-foxypi-arduino-nano-metal-detector Actual schematic - https://acdc.foxylab.com/sites/default/files/FoxyPI_v3_mkII_cir_zoom.png Current firmware version - 3.8 (see link on https://acdc.foxylab.com/node/47) This is closed source project. Since I was doing the project for myself, I did not use a printed circuit board. Best regards, Alexey

FoxyLab

2 years ago

The pulse repetition rate can be changed in the settings menu (10 - 200 pps). For L2 I used a coil from a faulty computer power supply (large "yellow" coil). I played with the neural network for curve shape discrimination (https://habr.com/ru/post/435884/). In my case, discrimination was only possible for objects the size of a dumbbell or a helmet, so I paused research in this direction.

Anonymous user

2 years ago

Hi sir I try your dedektor but I cant load because no ino file how can load myarduino nano code ?can you help me please best regards

Anonymous user

2 years ago

I need source code sir thanks help me please servet.pulsededektor@gmail.com pulsearge.com write me please

Anonymous user

2 years ago

Thank you vermuch sir Alexey so I will try with avr dude and ı make diffrent style dd-coil pulse use opa27 annd 37 opamp and dual mosfet ,diffrent style ı write slowly code I think have a afew problem timing and timer with atmega 8 pu I workıng still , thanks again visit and joined pulsearge.com allthe best regards sir Alexey ,,,take care godblees you ,,

FoxyLab

2 years ago

Hello, sir! You may hex-file upload to Arduino with avrdude -> link to hex-file for version 3.8 - in Firmware topic of project description. This project is opened circuit, but closed source of firmware.

Anonymous user

2 years ago

Please send me source code v3. latcakir@gmail.com

Anonymous user

2 years ago

Thankyou for a great project ! A Quick Question, are R1 (1K0) and/or R2 (390R) a high(er) wattage resistors ? TIA

FoxyLab

2 years ago

Thanks! 1 W - for better reliability.

Anonymous user

2 years ago

Ein sehr schönes Projekt! Eine Bitte hätte ich dazu: ich kann kein passendes Display finden.....ist es möglich die Type hier bekannt zu geben? Vielen Dank, K. Thür

latcakir

3 years ago

Please send me source code v3. latcakir@gmail.com

Anonymous user

3 years ago

I know this is old project but can u provide the source code for the latest version of firmware ? I am trying to build my own metal detector your code could help me understand different aspects better. if u are willing to provide source code my email address is hzaib76@gmail.com.

Anonymous user

3 years ago

Thank you Alexey for this project. I am oufbuzz, living half in Africa and half in France. I would like to realize it, but as Mamaev found two years ago, I also think there will be a short circuit on the Bat1 battery. I have been following all your discussions about this, but I am not aware of the end. Where can we find the latest version of this project? Would it be possible to have the source code of the .HEX file version 3.8. Is there a PCB to make it available? Many thanks for this project.

Anonymous user

2 years ago

Thank you for your explanations and directions. I have started the assembly. I hope that it will work well as with the others. My concern would be to change on demand the frequency, which to change sometimes also L2. Is this possible? My needs are mainly oriented in the search for gold. Since the source code is closed, thank you for publishing the project, can we transfer the detection indications, on a small arduino screen in the form of a bar graph, at the same time as the indications audible by the buzzer. That would be great. I have already seen it in other arduino projects. It would be very interesting for me to add a discriminator to distinguish ferrous metals from non-ferrous. I am sure you have already thought about this problem. Do you have a solution? M Thank you for this project and the answers you can give me. Translated with www.DeepL.com/Translator (free version)

FoxyLab

2 years ago

The pulse repetition rate can be changed in the settings menu (10 - 200 pps). For L2 I used a coil from a faulty computer power supply (large "yellow" coil). I played with the neural network for curve shape discrimination (https://habr.com/ru/post/435884/). In my case, discrimination was only possible for objects the size of a dumbbell or a helmet, so I paused research in this direction.

FoxyLab

2 years ago

Hello from Belarus! If you look closely at the circuit of my metal detector, you will notice that there are two grounds in the circuit - GNDA & GNDD, indicated by different icons and not connected to each other ;-) Therefore, there is no short circuit in the circuit. And accordingly, there can be no discussion on this topic :-) Main page - https://acdc.foxylab.com/node/47 (on russian, use Google Translate). On english - https://hackaday.io/project/167704-foxypi-arduino-nano-metal-detector Actual schematic - https://acdc.foxylab.com/sites/default/files/FoxyPI_v3_mkII_cir_zoom.png Current firmware version - 3.8 (see link on https://acdc.foxylab.com/node/47) This is closed source project. Since I was doing the project for myself, I did not use a printed circuit board. Best regards, Alexey

Anonymous user

4 years ago

Hallo Alexey. First thanks for this tutorial. I decided to have some fun and build this metal detector... Want to make a small PCB, but having some questions... 1) Where i can find latest schematics? 2) How does L2 coil looks like ? can you share photo, specs etc. 3) i know you don't want to share INO code but do you accept suggestions for upgrades? 4) any possibilities to add headphones output? I'm not electronic specialist but I'm handy with my 3d printer so when i get my PCB done i want also to add 3d printed case and search coil.

Anonymous user

4 years ago

Hi sir I try your dedektor but I cant load because no ino file how can load myarduino nano code ?can you help me please best regards

FoxyLab

2 years ago

Hello, sir! You may hex-file upload to Arduino with avrdude -> link to hex-file for version 3.8 - in Firmware topic of project description. This project is opened circuit, but closed source of firmware.

Anonymous user

2 years ago

I need source code sir thanks help me please servet.pulsededektor@gmail.com pulsearge.com write me please

Anonymous user

2 years ago

Thank you vermuch sir Alexey so I will try with avr dude and ı make diffrent style dd-coil pulse use opa27 annd 37 opamp and dual mosfet ,diffrent style ı write slowly code I think have a afew problem timing and timer with atmega 8 pu I workıng still , thanks again visit and joined pulsearge.com allthe best regards sir Alexey ,,,take care godblees you ,,

FoxyLab

4 years ago

Minor update ( version 3.8 ) is ready: improved display of signal curves in test mode (through earlier reading of preset settings, including contrast).

Anonymous user

2 years ago

can you help sir please no ino file how can load with ide nano? thanks

Anonymous user

4 years ago

Amigo Alexy, Entiendo que los detectores por Induccion de Pulso NO necesitan el modo balance de tierra, esto es cierto del todo? y si fuese un detector VLF cual deberia ser el metodo de Balance manual o automatico mas efectivo, por hardware o software?. Tienes alguna informacion que pueda ayudarme? . mi correo es vextorst@gmail.com. mi WS: +584124160819

FoxyLab

2 years ago

¡Buenas tardes! El equilibrio es necesario, pero no es tan crítico como para los detectores VLF. Cuando enciendo mi detector, se realiza el autoequilibrado (también se puede reiniciar presionando un botón si las propiedades del suelo han cambiado mucho). Desafortunadamente, no tengo buenas habilidades prácticas en el campo de los VLF detectores para darle un consejo definitivo.

FoxyLab

4 years ago

Influence of the value of the GUARD parameter on the detection range of the golden ring (L): GUARD L, cm 500 ---> 12 750 ---> 10 1000 ---> 8 1500 ---> 7 It is possible to decrease it even below 500, but in this case false positives may appear.

Anonymous user

4 years ago

Hello Alexey! I have made your project. It works good. I also made a PCB with SMD Parts.The PCB for the display can be separated. Here is no way to show it. I also have made a Version from your first Detector which works with one Voltage Source. It works also good. The Display ist not the best Solution. There are many Oled Displays which are not so sensitive. You have made a good and interesting Work!

FoxyLab

2 years ago

Thanks!!! It's great that everything worked out! I plan to make support for other displays, moreover, the type of display will be selected by jumpers. I have experience using the OLED display in my bike computer (https://acdc.foxylab.com/velo). Here https://www.geotech1.com/forums/showthread.php?17931-Arduino-metal-detector/page7, enthusiasts also design circuit boards for FoxyPI.

FoxyLab

4 years ago

FoxyPI firmware v3.7 is ready! What's new in version 3.7: * small code optimization was performed to increase the stability of the metal detector + beep indication for errors ERR 01 and ERR 02 added

Anonymous user

4 years ago

Alexey. Thank for sharing this valuable circuit with us. I have a question. i need your help in my project. i want to design a metal detector which can sense tiny (like 1 inch Nail) moving particle . let suppose the speed of the the particle will be 22 meter per minute. i will be thankful to you. can you help me in this matter. Thanks in Advance

FoxyLab

2 years ago

Thanks! To reduce the reaction time, it is necessary to increase the pulse repetition rate in the detector coil.

FoxyLab

4 years ago

FoxyPI firmware v3.6 is ready! What's new in version 3.6: + added the ability to configure the guard interval using the GUARD item of the service menu; + added auto-tuning of levels 1 and 2 of the audiovisual indication in static mode; + integrated test mode (to activate, after switching on, hold the control button until the graph of the signal curve appears)

FoxyLab

5 years ago

I decided to numerically evaluate the stability of my metal detector - it turned out to be quite satisfactory: after 15 minutes of operation, the detection range of targets decreases by less than 4%.

Anonymous user

5 years ago

Hello Sir i am Ananda from sri lanka please let me send V 5 arduino code. info.ecojump@gmail.com Thanks.

FoxyLab

2 years ago

Hello! HEX and ELF files only, its closed source project.

FoxyLab

5 years ago

The FoxyPI firmware version 3.5 is ready. What's new: added the ability to adjust the display contrast using the CONTRAST item in the service menu

Anonymous user

5 years ago

Hello! I built your metal detector with a loaded v3.4 version on an Arduino Nano. All great, but it's barely visible on the display (too little contrast). I'm using the LCD from here: https://www.aliexpress.com/item/32729495509.html?spm=a2g0s.9042311.0.0.3da24c4dDGAzID I tried your first version (https://github.com/Dreamy16101976/foxyPIv1/blob/master/FoxyPIv1.ino) and had to increase the value in line 63 from "const byte CONTRAST = 50; // LCD contrast" to "const byte CONTRAST = 60; // LCD contrast "so I could read normally from the LCD. Considering that version 3.4 is not GNU, is it possible to get HEX-corrected gain or just what location to fix in HEX for the correct contrast on my LCD. Greetings Alojz R.

Anonymous user

2 years ago

Yes, my LCD is red. The enclosed instructions state that Vcc may also be 5V. I tried with Vcc 5V and 3.3V but the contrast does not change. Of course, setting the contrast in the menu is the best solution. Please let me know when there is a new version with a new menu. Thanks for the quick reply and best regards. Alojz R.

Anonymous user

2 years ago

Great! Now I can adjust the display to the right contrast. The downside is that the power-on contrast is not set yet. So when the countdown ends and the image disappears, the contrast is set correctly. Otherwise it doesn't bother me too much. Thanks again for the quick fix. Alojz R.

FoxyLab

2 years ago

Hello! Thanks for report! I’ll do it easier - I’ll add a contrast setting to the menu. Best regards Alexey P.S. Your module is "red" LCD module, but i used "blue". What is your LCD VCC (supply voltage) - 5 V or 3.3 V?

FoxyLab

2 years ago

Yes, contrast set to default (50) from power-on to settings reading from EEPROM.

FoxyLab

2 years ago

The project was carried out using a hinged installation. PCB not exists.

FoxyLab

2 years ago

Ready (see comment below)!

Anonymous user

2 years ago

please,they would be gerber data?

FoxyLab

5 years ago

Video illustration of starting procedures: https://youtu.be/6YwlmcuxyKs

Anonymous user

5 years ago

Nice project, but without the source code, I'm not building it. Make this an open source project and let others improve on it.

FoxyLab

2 years ago

I respect your opinion, but the status of the project will not change.

Anonymous user

5 years ago

Thankyou for a great project ! A Quick Question, are R1 (1K0) and/or R2 (390R) a high(er) wattage resistors ? TIA

FoxyLab

2 years ago

Thanks! 1 W - for better reliability.

FoxyLab

5 years ago

The final firmware version 3.4 is ready! What's new: MOSFET overheating is excluded increased stability added auto-tuning interval between ADC samples added display of the signal curve after auto-balancing

Dreiduke

5 years ago

I Built it, And i got it working. first Test the MOSFET got extremly hot, next time Test its working, and i tryed to adjust Frequency and Pulselenght, then the MOSFET burned. May be there is something wrong in the Circuit in front of the MOSFET, or so?

Dreiduke

2 years ago

now its Working with an IRF710 MOSFET I connected the Display light wrong, (on Plus not on GND as it should) and somehow it burned the FET i used ~31 windings of 0,5mm chopper wire, and it works great.

FoxyLab

2 years ago

Version 3.4 is ready!

Anonymous user

5 years ago

Nice. What is the value of L1 and L2? L2 looks like a filter for the power supply, but L1, the search coil has no description, or I'm just blind today. I would assume 0.4mm wire 25-30 turns around a 20cm diameter form. Could you tell me if that is right? Thanks.

FoxyLab

2 years ago

Thanks! Yes, L2 - filter coil. My L1 coil - diameter 25 cm , 0.7 mm (diameter) wire, 27 turns.

tarbear123

5 years ago

Does this use magnets, as I can't use magnets

FoxyLab

2 years ago

No, this device doesn't use magnets, but coil generates magnet field, yes.

Anonymous user

6 years ago

WE make this but isnt work.May be have a some mistakes.Can u help me.Can u send me arduino code for version 2 aaset355@gmail.com.PLS

Anonymous user

2 years ago

THANKS for reply. I make this.But We only see "zeroning" else nothing.Why?.I need a your help

Anonymous user

2 years ago

We Can chatting on Gmail.Can u write me

FoxyLab

2 years ago

Wait for the zero level update to complete (the metal detector stops beeping) and briefly (shorter than two seconds) press the button to complete the balancing and switch to the search mode.

FoxyLab

2 years ago

It is easier for me to answer here, and similar questions may arise from other people who wanted to make this device.

FoxyLab

2 years ago

Describe what is not working for you. I'll do a test sketch the other day.

Anonymous user

2 years ago

apakah anda bersedia mengirimkan file.ino nya? saya mau mempelajarinya, kalau file HEX, saya bingung

Anonymous user

6 years ago

Hi, Very nice project, I wanted to build something similar in the past. Now I feel, I will follow your tutorial and experience. But I found some mistake in the circuit diagram, I think you have a Bat1-Ground short circuit. You have to cut the line between the two protecting diode. (VD1 and VD2) Anyway, it's a good design! :)

Anonymous user

2 years ago

Hi,İ have one question.We must cut the line between vd1 and vd2

FoxyLab

2 years ago

Very thanks!!! About grounds - Its typical question ;-) My circuit has two ground - digital ground (chassis (?, my english is bad) symbol) and power ground (grounding symbol) and two batteries - Bat1 - for power, Bat2 - for digital. Pleased to answer your questions

FoxyLab

2 years ago

P.S. I remind you that in the scheme two grounds are not interconnected

FoxyLab

2 years ago

No, why? See my reply above.