In this scheme, the firmware of the PIC microcontroller is seriously improved.
Firmware files now exist separately for both PIC12F675 and
and for PIC12F629, but this is only for version FM2 v2.
The essence of the firmware upgrade:
-Frequency now does not walk, that is, it is often not necessary to restart the baby, it has become very stable, I personally tested it, restarted it all day only when the coil bent accidentally; it is not flooded with me.
-Added power on alert function. For example, if you put it and forgot to turn it off, the baby every 2 minutes will remind himself of a pleasant sound.
-Also added a function of indicating the battery charge. If the battery voltage drops below 5.5 volts, the detector will emit a characteristic signal and both LEDs will light up. But this function is only possible with the PIC12F675. In 629, this function is not.
The circuit itself is also slightly modified, but not much, just added a couple of resistors.
Here is the diagram itself.
The circuit uses a LM317 voltage stabilizer, pinout of its legs from the bottom in the photo.
The board itself was quite compact.
And easily fits in a small case.
At the huge request of all the inhabitants of our sites, not too lazy and compiled the entire list of the necessary components. All of them are presented in the photo.
The inductance of the coil in this metal detector. Now it’s 1500 mH,
Look, make no mistake when you reel the coil through the program. It is better to wind through Coil32 program, see how to wind win in my previous articles and the program is there too.
Who needs already flashed microcontrollers PIC12F675 or PIC12f629 contact me by mail
Well, of course, below is a video of the work of this metal detector, as well as firmware files and a circuit board file.