My 3 year old daughter wanted a "music box" like her older brother's, so I have made this for her (for Xmas).
It's a 28x1 with serial LCD to a 24x2 LCD, connected to a VMUSIC2 module and a quaint old 128Mb usb drive. It has a stereo amplifier, with bass and treble, salvaged from an old PC peripheral.
It has 4 ohm speakers and drives from 5V, so is a good fit for this project.
Power is from 2 x 3.7V 2200mAh laptop batteries, stepped up using a LM2623. It has a ladybird on-off switch, and a second for sending the sound to headphones (volume limited of course!).
The little door at the front (will be locked!) is to remove the drive and add new songs when required.
The caterpillar features numerous LEDs:
- orange - play-all mode
- green - random mode
- blue - battery getting low
- red - playing song
The 5 buttons beep gently when pressed, and control:
- red - battery check - lets her know when to ask Daddy to recharge (it auto shuts everything down if the batteries are lower than 2.8V, to protect them)
- purple - play / pause
- yellow - back to previous track
- white - skip to next track
- orange - switch between random / play-all modes
All of the tracks, filenames etc are written to the usb drive along with the tracks themselves. The display shows the track elapsed time while it's chugging along. The whole code comes in at a whisker under 2000 bytes.