WaveRP is an Arduino library for recording and playing Wave files with the Adafruit Wave Shield. It records 8-bit mono files at 4,000 to 44,100 samples per second. Use of the Wave record/play library, WaveRP, requires the following: Arduino with a 5 volt 328 processor. Low noise power source such as a nine volt DC adapter or battery. Adafruit Wave Shield (version 1.1 is best but 1.0 works) Microphone preamp. A circuit for a simple preamp is included in the documentation. Microphone, PC type with 3.5 mm plug. See the documentation for details. SD/SDHC formatted with 32KB allocation units.
The Wave Shield!
Adding quality audio to an electronic project is surprisingly difficult. Here is a shield for Arduinos that solves this problem. It can play up to 22KHz, 12bit uncompressed audio files of any length. It’s low cost, available as an easy-to-make kit. It has an onboard DAC, filter and op-amp for high quality output. Audio files are read off of an SD/MMC card, which are available at nearly any store. Volume can be controlled with the onboard thumbwheel potentiometer.
This shield is a kit, and comes with all parts you need to build it. Arduino, SD card, tools, speaker and headphones are not included. It is fairly easy to construct andanyone with a successful soldering project under their belt should be able to build it.
The shield comes with an Arduino library for easy use; simply drag uncompressed wave files onto the SD card and plug it in. Then use the library to play audio when buttons are pressed, or when a sensor goes off, or when serial data is received, etc. Audio is played asynchronously as an interrupt, so the Arduino can perform tasks while the audio is playing.
- Can play any uncompressed 22KHz, 16bit, mono Wave (.wav) files of any size. While it isnt CD quality, it is certainly good enough to play music, have spoken word, or audio effects. Check out the demo video/audio at the webpage
- Output is mono, into L and R channels, standard 3.5mm headphone jack and a connection for a speaker that is switched on when the headphones are unplugged
- Files are read off of a FAT16-formatted SD/MMC card
- Included library and examples makes playing audio easy
- Please note that the library rather bulky, requiring 10K of flash and more than 1/2 K of RAM for buffering audio. It works fine using an ATmega168-based Arduino (or compatible) but for more complex projects I strongly recommend upgrading to an ATmega328!
More information, including design notes, schematics, library, examples, etc is at the Wave Shield webpage