HackFFM-Duino Chime

Motivation

LeandraChristine needed a small solution for sound in a project. Since I was designing lots of PCB’s anyway I decided to also realize this one. Another requirement was fast responsiveness. The SimpleSDAudio-library from Tut provides just that. Tut helped quite a lot with the circuit design in this project.

Features

The board is carrying:

• Atmega328
• MAX9098306 3.7W stereo Class D amplifier
• SN74LVC2G14 dual Schmitt-Trigger with its own low noise power supply
• microSD-Card Slot
• 74LVC1G53DP Analog Switch, to set the gain of the Class D amplifier (3 levels)

The controller itself is running on 3.3V (because of the SD-Card). The supply voltage is 5V.