Instead, he drew up a simple schematic that used an Arduino Nano, an FM radio module based on the TEA5767, and an audio amplifier based on the LM386. A single button on the Arduino helps cycle ...

Digital (pwm) pin D3 drives the piezo-buzzer through a PNP transistor ... and connects pins 4 and 5 (UART) to Arduino pins 0 and 1. The APC220 module (see next image) has a total of nine pins (only ...