[Usmar A. Padow] put together an Arduino Uno, SD card, four line character LCD, and PS/2 keyboard. but he’s also included alternative options to go without an LCD screen by using a computer ...

Normally driving an LCD requires seven connections to pins on the display, but by using a shift register, [Phillip Warner] at Arduino Playground was able to drive an LCD using only 3 wires.

We might think that an AVR microcontroller – e.g. the ATMega328p adopted by the Arduino UNO boards – has the sufficient number of pins to manage an alphanumeric LCD. In a complex industrial machine ...

To deal with this you’ll want to supply the Arduino 5V via the RAW pin (it’s regulator will then supply 3.3V to VCC feeding the Host Shield and Bluetooth module). Then route a wire from this ...