I2CChip.com: Alphanumeric LCD Module Interface

A simple interface from I2C to Alphanumeric LCD modules (44780 type).

Note: This module is no longer available. Our BL301 Interface IC and module is far easier to use and is recommended. This still shows how to do it with the PCF8574 I/O module.

Contents This is a minimalist interface using an 8574. It uses the 4 bit interface mode of the standard HD44780 style LCD drivers found on almost all modules. (N.B. Graphics modules have a totally different interface).

7 pins are used for the 4 bit interface mode.

The 8th is used for a power switch for the backlight or for the LCD module itself.

Why switch the 44780's power, you ask?
Well these modules are a 4 bit micro, and they will just lock up and stop responding when glitched or ESD'd.
Regular power-on-resets prevent the embarassing situation of a fire alarm that works perfectly, but the display hasn't shown anything for 6 months!

Schematic (pdf)

Dimensions: 44x50mm

I2C Connector: I2CChip 6 pin Micromatch for I2C Bus.

LCD Connector: 14 pin 0.1". Single row, and double row headers on board.

(Sorry not available at present)

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