With the rise of the maker movement, and the popularity of Arduino and other microcontrollers in particular, serial terminals are experiencing a bit of a resurgence. If you’ve ever used the Arduino IDE, you have almost certainly taken advantage of the built-in software serial terminal. That allows you to send and receive data from the Arduino via a USB connection. But, it also requires an actual computer. That’s overkill for just receiving serial communication, and so you may want to build this Tiny Terminal 2 instead.
The Tiny Terminal 2 can receive and display data from an Arduino or any other device that has a 9600 baud serial interface. It’s powered by an ATtiny85, which comes in a small, breadboard-friendly 8-pin package that is incredibly affordable. That’s connected to a 256x64 greyscale OLED display from AliExpress, which can display eight lines of 42 characters each. The display is built on an SH1122 driver chip, and has its own memory to store data written to it, so you won’t need a separate memory buffer.
Follow the instructions to wire up the ATtiny85 and display on your breadboard. The schematic is surprisingly simple, and the primary functions of the circuits are to bring the ATtiny85 5V power down to the the 3.3V required by the display, and to provide a capacitor and resistor that are necessary to properly power-up the display. You’ll need an AVR programmer to upload the code to the ATtiny85, but when you’re done you’ll have an inexpensive, portable, auto-scrolling serial terminal!