In a previous blog entry, I mentioned that I had picked up a $12 Mattel Juicebox that I was thinking about hacking. I’ve done relatively little with it since then, but this morning I felt compelled to at least convert a picture from normal jpeg format to the internal format used by the player, without of course using the Windows XP software they ship with the thing (I think I already threw away the CD in fact…)

The format is simple: 240×160 12 bit values, with 4 bits for each of red, green and blue. That’s it, no headers at all. Oh, and you must name the file with a .jbp extension (Juice Box Picture?). I wrote a simple program to convert ppm files to this format (without dithering, but with 4 bit color it isn’t terrible), mounted an SD card, copied the file over, unmounted it, and then put it in the juicebox.

Voila. Worked perfectly.

Unfortunately, I’m camera-less today, so I’ll update with a picture later today. Witness the picture to the right.