Big Text Scroller
The Big Text Scroller is in production now.
It's a 7xN text display, where N is expected to eventually be large.
The substrate for the LEDs is the grid itself. It's composed (currently) of T1 red LEDs, with steel piano wire (1/32nd in.) as its backbone.
Each set of 16 columns is driven by a single STP16DP05 16-bit serial LED driver. The STP16DP05s will chain into large virtual shift register that runs the entire length of the display.
The 7 rows (high side) will be driven by a set of fast P-channel power mosfets. As the number of columns increase, it is possible that we'll have to have "repeaters" for the P-channels, as well as independent power supplies.
The display will be broken up into 32-column segments that can be plugged in to each other. This will simplify setup, disassembly, and debugging.
LED spacing on the initial segments is 1/2".