dhenry:
Connection:
MOSI pin: from the mcu to shift register's data pin (pin1+2 on HC164 and pin 14 on HC595). LCD's RS pin tied to this line as well.
SCK pin: from the mcu to shift register's serial clock pin (pin 8 on HC164 and pin 11 on HC595)
Enable pin: from the mcu to the lcd.
What about the RCK line (pin 12) on the HC595? Anything connected to that? A schematic for your 3wire HC595 interface would be welcome.
Advantages over other 3-wire solutions:
- It allows 8-bit as well as 4-bit mode.
- It uses no parts other than the shift register.
- It allows HC164 as well as HC595.
Are there any example 3-wire interfaces that drive an LCD in 8-bit interface mode, please? I designed one that uses 3 pins on a 74HC164 but I was wondering if there were any others?
TIA, Mike