K8LH 2-Pin 74HC595 LCD "8-bit" Backpack 2014-05-23

Here's a relatively simple Backpack design for HD44780 type LCD displays that requires just two I/O pins on the host microcontroller while driving the LCD display in its "8-bit" interface mode.

**broken link removed**

Theory of Operation

Note that the 'E' line from the microcontroller is directly connected to the 'RCK' pin on the 74HC595 and the 'E' pin on the LCD. In this way the 'E' line performs double duty by latching data from the 74HC595 internal shift register onto its...

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