The simplicity of this metal detector brn 1 is so great that even for beginners, it does not need much assembly description.  If there is a problem, please let me know in the comments section, I will reply as soon as possible.

Advantages: 

• Very high stability
• High sensitivity
• Fully digital (5 keys and 16*2 LCD)
• Automatic balance
• low consumption  

* I will also watch the video of the machine working later .

Schematic Diagram

Printed Circuit Board

It is good that the pcb is made of fiberglass, but it has no noticeable effect on the work of the circuit!

Part List

All the parts are quite common, you will not have any problems to get them.

Resistances ( one percent error )

+all 0.8 watts

• 1 kilo 3
• 10 kilos 1
• 100 kilos 2
• 4.7 kilos 1
• 470 Ohm 1
• 100 ohms 3
• 330 ohms 2
• 1 megaohm 1

• 1 kilo 5 watts 1

• Potentiometer 100 kilo 1

Capacitors

• 1600u-10v(2200u) 1
• 4700u-16v 2
• 100n 1
• 22p 2
• 30p 1

• PIC16F876 micro + 28 pin socket
• LM358 + 8 pin socket
•  1 7805             
• IRF9640 MOSFET         
• BC517 1
• 2N3904 1
• 1N4004(4007) 1
• 1N4148 2

Other parts

————-

• Push button number 5 ->     H+,- : adjust sensitivity    
• S+,-: volume hundred   
• TPR: Ground Balance 
• LCD 16×2
• 4MHz crystal
• 12 volt battery

• Coil: Coil with a resistance of about 2.5 ohms
• Small speaker

Assembly:

To begin with, it is better to prepare parts before making the board, although all parts are quite common.

I posted a tutorial to make a board using the ironing method, you can read it.

First, install all the resistors (especially the resistor under the micro socket so that you don’t get into trouble later)

Next, capacitors and silence.

Note**: before placing micro and 358; Check the 5V circuit (just to be sure).

The installation of keys and LCDs is completely clear and there is no room for explanation, but if there is any question, I am at my service.

– Micro programming may be a problem for many people. I put the hex file to download.

To program, you need a programmer whose price is around 30 tomans! I have explained the full programming tutorial in a separate post, you can use it.

After montage, it is time to test and teach how to use this metal detector.

Soon, I will put more explanations and making loops and videos in a separate section.

Full file including pcb pdf + parts list + hex file and more pictures.

Download files:

• Schematic diagram
• brn_pi-1.1_PCB1
• Firmware