This project uses an Arduino Pro Mini, SD card reader, LM386 audio amplifier, and a 555 timer.
A list of short phrases are stored on the SD card. When a button is pushed, the Arduino powers up and randomly plays one of the stored phrases. Then it powers down. The 555 controls the timing for powering the Arduino. By using the 555, the overall system uses much less power since it is only powered for about 10 or so seconds (choosing different timing components will achieve different power-on times).
The wav file is played using the TMRpcm Arduino library. In order to play a wav file, it must have the following characteristics:
Name: maximum of 8 characters with no extension
Samples per second: 16000
Channel: Mono
Bits per sample: 8
Using Audacity, any wav file can be reformatted to these settings.
Schematic:
Board Layout:
Fritzing file with code:
Here is the finished product!
