That is interesting in and of itself but the particularly remarkable feature of this project is its novel use of printed circuit boards for casing and instrument panels.

Using an inexpensive board and a clever signal processing algorithm, this DIY project delivers a precise, real-time guitar tuner that’s easy to use.

Current signals at 4...20 mA are frequently used to send process signals to controllers in industrial applications. Compared to an analog voltage signal or digital communication, the current loop ...