I've been using the time I spend on trains getting too and from my day job to work on the code for another project and its associated hardware.

The firmware is for a 16F690 and provides a serial based controller for four seven segment LEDs. The software is coming along nicely but I haven't finalised the PCBs yet.

The cunning plan is to have the controller, load resisters and transistors on one board and the LEDs (either 4x 1-digit, 2x 2-digit, 1x 4-digit or 1x 88:88 clock) on another with a common set of interconnecting pins (possibly a 2x6 pin header).

The 1x 4-digit and 88:88 displays are the easiest to work with. There isn't any nice way to connect all the segments when using 4x 1-digit or 2x 2-digit seven segment displays, especially if you're trying to stick with a single sided PCB.