“Inexpensive and extremely stable and sensitive metal detector made using an Atmega8 microcontroller.
Quite by chance these days I got in my hands a “Clone PI W” metal detector module, so I decided to immediately do a small review and compare it with my previously made DIY Metal Detectors.
At first glance, the module is solidly made, the elements are precisely placed and well soldered. The price is less than $50, including postage.
In this case, it is an SMD version of this detector, and you can find the same metal detector made with standard components made according to an identical schematic diagram. For the power source I use three lithium-ion batteries connected in series and it is just under 12V.
The coil is identical to the one I use in my DIY Pulse Induction Metal Detectors, and consists of 25 turns of enameled copper wire with a diameter of 0.4 to 0.6mm. The diameter of the coil is 200 mm. This coil dimension represents a kind of compromise in relation to coils specialized for detecting small objects (which are mostly of smaller diameter), and those made for detecting larger massive objects at a greater distance (in these the diameter can be 1m or more ).”