I2C 16x2 LCD-Module Expander

Design by: 6839

This PCB interfaces the I2C bus to a 16x2 character LCD-Module with a socket of 16 pins in a row: 14..1,16,15. The LCD controller for this PCB is a KS0066 or similar. The used U121 is a MCP23017 I2C port expander. JP120, JP121, JP122 are the address selectors. Q131 is a NPN-transistor BC337 R131 having 15k. R111, R112 are the I2C pull-ups with 1k5. C121 for blocking with abt. 470nF. Poti R141 is a 10k linear type. The LCD-Modules is adapted with a 16-way, 2.54mm PCB connector. This PCB should be under the LCD module. My first hand-made version works pretty fine. Cheers DF4IAH, Uli.