MFM3 is a metal detector app (pinpointer) with metal discrimination. When we put a metal object near to the coil the frequency changes and in this way the app detects the changes of the frequency and when there are changes it detects that there is a metal object nearby. This pinpointer is capable of distinguishing ferrous metals from non-ferrous metals.This app works with the help of a small circuit (you can find it below). The circuit is fed from 3.5v to 5v. The circuit is very small and is made with easy-to-find components. To know about new updates and new projects, subscribe to my YouTube channel.
Components we need:
To test different configurations we can change the C2 value to get different working frequencies, in the app we can see the frequency of work and how the frequency changes when we change capacitor C2. In the menu of the app we can also choose the precision. The best precision to select the highest but if your smartphone is not able to work with this precision we can choose the low precision.