concept circuit in category arduino

This is an excerpt from Manning's book Arduino in Action. Login to get full access to this book.

Figure 3.13. A speaker has been added to the circuit, with which you’ll output a tone.

The circuit has three main parts in addition to the Arduino: a 5.1 V zener diode, a 1M ohm resistor, and a piezoelectric transducer. As already described, the zener diode and the resistor are connected in parallel to the piezoelectric transducer.

Start by placing the three components onto the breadboard, paying careful attention to the polarity of the piezoelectric transducer, which normally has a red and black wire presoldered onto it using a special low-melting-point solder. The black wire connects to the GND part of the circuit, and the red connects to the Arduino’s analog input A0.

It’s now time to look at the Arduino side of things, beginning with a sketch, and then building a circuit with an LED connected to pin 9.