Arduino metal detector

Arduino metal detector

I have seen arduino metal detector circuit on net. see circuit

And see sketch cod: https://dl.dropboxusercontent.com/u/2248531/blog/metal_detector/metal_detector.ino

I have tried it on my arduino Uno r3 at mega 328 r-b ,it did not work. When up

loading sketch (library found not working).some did work for them, some are not.

To check if my circuit correct and working

 I checked circuit by powering it with 9 v battery near am radio and moved piece of metal over the coil, radio responding to metal movement.  

I think the reason was the timers.

He mentioned oscillator circuit feeds at around 160kHz signal to pin 5 of the Arduino

So checking if reason not working was timers of my arduino, I choose similar circuit with less kHz pulsing and it was am radio blf metal detector oscillator feeds 120 kHz. See circuit

And to make it work on my arduino with same code sketch, I just connected a wire from transistor E side to arduino pin 5 digital and reload same sketch and that is it, it worked. See modified sketch