by: DCEM
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.
Choose between 8bit Stereo or 16bit mono Sound.
Board size: 15 x 30mm(0.6 x 1.2 inches)
8 Pins are accessible including i²C PINS
Design Files
License
Licensing CC v4.0 Share-Alike (http://creativecommons.org/licenses/by-sa/4.0/)
I started out with the open log design. Although there is not much left of it, it was some help.
I also used libraries from sparkfun and adafruit.