Arduino GhostBox

I tried to create a better sounding GhostBox (Ovilus) using the TalkiePCM library, but not only is the code too large for most Arduinos (Uno, Nano, ProMini, ATmega328), but the library is unable to work with SAM-based Arduino/Adafruit boards.

This project is derived from two online based "GhostBox" projects- the code and circuit comes from this link https://www.sandiegohaunted.com/diy-ovilus-style-word-database/

I have redrawn the schematic, made modifications and laid out a new circuit board using the tiny Adafruit ItsyBitsy M4 circuit board.

To make this board easy to assemble, I incorporated ready-made modules: a generic LSM9DS1 module that has 4 pins on one side (GND/VCC/SCL/SDA), an OLED 128x64,  the #GF1002 PAM8403 amplifier module with the on-board volume control and the TP4056 usb Battery Charger module.

A Low-Pass audio filter circuit comes just before the PWM Audio enters the PAM Amplifier circuit to help "antialyze" and improve the sound

Two #14500 AA LifePo4, 3.2v rechargable batteries power the unit through a +5v Voltage Regulator.

Since I used very small surface-mount components, I recommend having this circuit board populated by JLCPCB and install the modules yourself!

Two 3 watt, 8 ohm Speakers are connected via connector CN1.

Code compiles for the ItsyBitsy M4 and the Feather M4 from Adafruit.

Circuit board is unverified.