Alternately, the Arduino has many sets of SDA and SCL pins - half as many as it has a total of functional digital (including most of the analog) pins.
I am looking to drive approx. 750 leds & monitor some buttons.
I was thinking the MCP23017 would do me right on an uno or mega. But If my Calculations are correct I can only drive 8 x 16 leds (128) per i2c channel. and the Arduino's only have One set of CLK/DAT pins.
What other options are out there besides charlieplexing?
someone earlier mentioned being able to run i2c on more than just pins 4&5 with "software",
Ar-Ds (Arduinos) - thought i was being clever....apparently not... just 1 (8x16) i2c (1 i2c channel is capable of 8x16 (128 pins))an i2c w/ software? (someone earlier mentioned being able to run i2c on more than just pins 4&5 with "software", how is this possible?)