This high-frequency signal is crucial for detecting metal objects, as it changes when the detector passes over a metallic object. The Arduino plays a pivotal role in this setup.

There are other metal detector projects using AVR and PIC. This one is nice and simple. I do wonder why the 7.64khz frequency was chosen instead of something in the 15k to 20k range wasn’t used.

We’re still not sure exactly how [connornishijima]’s motion detector works, though many readers offered plausible explanations in the comments the last time we covered it. It works well… ...

A new Instructables page has been created to make an eco-friendly DIY metal detector using an Arduino Mega just been combined with a 3.2 inch TFT LCD ...

The Tsunami can also be used to measure signals> It does not use the Arduino’s ADC, but has its own high speed comparator, allowing it to measure frequency up to nearly 8MHz. A peak detector allows it ...

This sketch shows a Multisim SPICE simulation of a frequency threshold detector. If the input clock frequency is below the threshold frequency, the output is logic zero. If the input frequency is ...

The system here uses a cheap Arduino board, a few sensors, and a magnetic contact switch. It’s then hooked into the Adafruit IO and connected to IFTTT, so you can set up alerts in any way you like.