January 29th, 2022
—![](https://www.blogdot.tv/wp-content/uploads/2022/01/instead-of-sensing-the-presence-of-metal-this-tinyml-device-detects-rock-music.png)
After learning about the basics of embedded ML, industrial designer and educator Phil Caridi had the idea to build a metal detector, but rather than using a coil of wire to sense eddy currents, his device would use a microphone to determine if metal music is playing nearby.
Caridi started out by collecting around two hours of music and then dividing the samples into two labels: “metal” and “non_metal” using Edge Impulse. After that, he began the process of training a neural network after passing each sample through an MFE filter. The end result was a model capable of detecting if a given piece of music is either metal or non-metal with around 88.2% accuracy. This model was then deployed onto a Nano 33 BLE Sense, which tells the program what kind of music is playing, but Caridi wasn’t done yet. He also 3D-printed a mount and gauge that turns a needle further to the right via a servo motor as the confidence of “metal music” increases.
![](https://www.blogdot.tv/wp-content/uploads/2022/01/instead-of-sensing-the-presence-of-metal-this-tinyml-device-detects-rock-music-1.png)
As seen in his video, the device successfully shows the difference between the band Death’s “Story to Tell” track and the much tamer and non-metal song “Oops!… I Did It Again” by Britney Spears. For more details about this project, you can read Caridi’s blog post.
Website: LINK