I figured I'd mount volume controls to the side of the case and wire playback controls to the ancient original keypad.
The PIC18F45j10 microchip is a PIC microcontroller that does a lot of the dirty work on the Daisy.
It looks ridiculous, I know, but the sound quality is stunning. Plus, you can hear the love that went into this thing. I wired the keypad so that buttons 4, 5, and 6 control rewind, play/pause, and fast-forward, respectively.
First step (and the hardest) was surface mounting the small VS1011 chip in the top left corner. The VS1011 chip is an MP3 decoder, digital/analog converter, and headphone amplifier all in one little package. The tiny little pins were hard to line up straight, but it's close enough for rock 'n' roll. After that, I put down the resistors.
Aside from the fact that I'll have to keep the back open, it's a perfect fit! After all that work, it's hard to describe how exciting it was to hear music come out of this thing that was just a pile of parts a few moments ago.
Before getting started, I warmed up the soldering iron and laid out all the parts.
Next came the headphone jack (bottom right) and the SD flash memory card slot (bottom left). The Daisy plays music formatted as either MP3 or WAV files loaded onto FAT32-formatted SD or MMC flash memory cards.
An MP3 player is only as good as its enclosure. My 1978 "Little Professor" calculator game needed an upgrade, and the Daisy just barely fit.
This is a shot of the board before any of the components have been soldered on. The Daisy kit was designed by a San Francisco-area group called Teuthis and marketed under the Make Magazine brand name. The board measures 3 inches square.
Figuring out how to take advantage of the original Little Professor keypad was no easy feat. I used a multimeter and a lot of patience to determine how the leads worked together.
Here's a shot of me pushing the PIC18F45j10 microchip into place. Hold your breath and pray you don't hear any sharp, snapping sounds.
Here's a shot of the Daisy powered up and playing for the first time. The default volume is fairly restrained, though, so to get things cranked up, we'll have to wire some volume controls to the function pins on the bottom of the board.
Most commercial electronics use components that are shrunk down to nanosize blobs. This is not the case for the Daisy. Everything is big and beautiful on this board.
I popped in some fresh AAA batteries and connected the pack to the board.
You can customize the Daisy's volume control to be just about anything you want. For the sake of space, I used some switches from my personal stash to create a unique volume control. The red button will increase or decrease volume based on whether the switch is in the up or down position.
To get the battery pack to stay put, I used some industrial double-sided tape.