Is there I2C interface for 4x40 LCD?

4x40 LCD (hitachi compatible) has different pinout than all other character LCD (1x8 to 4x20) because the 4x40 has 2 separate enable line and the LCD is split funny to behave a bit like interleaved 2x40 LCD so I can't ghetto in a regular I2C connection. Is there a few-wires-as-possible solution ala I2C for 4x40 or am I stuck with 3 control, 4 data, and 2 enable lines per LCD? (edit I can probably share data across multiple LCD provided I get enable lines done right) My experiment already uses I2C for other function so it won't add burden if I can still use I2C on this LCD.

The I2C board for LCD that I can find are designed to be soldered directly onto LCD module and it would need some rewiring or a 3rd PCB board between LCD and I2C board to deal with pin difference, unless someone already makes I2C board that is compatible with 4x40?

There are plenty of I2C IO expanders that will do what you want. You may well have to write your own LCD library to support them though. One good IO expander, that I use a lot is the MCP23017 which has 16 IO lines - more than enough to run whatever LCD you might want.

Thanks, something to look into.