People who have grandmothers (and grandfathers) are fortunate. Although most of these old people are healthy and strong despite their advancing years, not all are so lucky and may be impaired in some way, mostly because of their failing eyesight and trouble with arthritic hands. Since they have a physical handicap, they find it difficult to operate a laptop, a DVD player or a tiny MP3 player. A Raspberry Pi (RBPi) with a large play button is actually helpful if it can read back an audio book.
This can be done in two ways. The RBPi player can have a single large button to pause and play, or have no buttons at all and be operated by NFC tags. The tags are best attached to empty CD or DVD cases, on which the details of the Audio book are printed in large letters for easy reading. Simply passing a case over the player will cause the specific audio book to start playing from its last state.
The player saves its state after every two seconds. Therefore, when the listener is bored or otherwise wants to stop listening, he or she can simply disconnect the player from its mains socket. Reconnecting it allows the player to get back to playing from its last saved state.
The RBPi player with a single large button works as a play/pause button when pressed. Going back to the previous track is easy if the listener holds the button pressed for more than four seconds. Copying files into the player is also a simple affair with a thumb drive. The files are copied into the thumb drive under a special volume label. As soon as it is plugged into the RBPi USSB port, the books are copied into the SD card and starts playing when the drive is unplugged.
For the single button RBPi player, apart from the RBPi and its enclosure, you will need a blue LED, some wires, a pair of speakers and of course, the large button. Among the software that you will need are – Raspbian image (Wheezy), mpd, mps, mpd-python, pyudev and a python script.
When the RBPi player is first powered up, it boots, starts the python script and waits with the audio book in pause. Since at a time only one audio book is stored, pressing the button starts the player. If the button is held pressed by more than four seconds, the player goes back one track. The player always remembers its last playing position.
As soon as a USB thumb drive is plugged in, the player stops playing, mounts the thumb drive, deletes the old audio book, copies the new one from the special name/label on the thumb drive and rebuilds the playlist. A flashing blue LED signals the end of file copy. Once the thumb drive is removed, the new audio book starts in pause mode, proceeding to play when the play/pause button is pressed briefly once.
Use of mpd allows the RBPi player to support wave, Musepack, MOD, MP4/AAC, MP3, MP2, OggFLAC, FLAC and Ogg Vorbis file formats.
