You need to connect the red and white wires (clock and data lines) to two separate ports. I used a breadboard for this, but you could also just solder an extra wire on.
- Red wire: PORTB0 (Pin 8 on Duemilanove) PORTC2 (Analogue Pin 2 on Duemilanove)
- White wire: PORTB1 (Pin 9 on Duemilanove) PORTC3 (Analogue Pin 3 on Duemilanove)
- Blue wire: +5V
- GND (unshielded): GND
To display images using the vmu_image program, produce a 48x32 text file with 'x' where you want the set pixels to be. I use imagmagick and go through pgm using this pipeline, which is not pretty but works:
convert mypic.png pgm: |python3 pgmtotxt.py - >mypic.txt