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.