PC-based USB oscilloscopes are*fast becoming all the rage. [Matt Sarnoff’s]*Terminalscope takes the reverse approach,*adapting an oscilloscope into a full serial terminal.*You may have seen something similar before in the Dutchtronix/SparkFun O-Clock, but [Matt’s] project goes one further by adding a PS/2 keyboard port*for full bidirectional serial communication, and with much sharper display resolution to boot.
The mostly VT-100 compatible Terminalscope is built around two AVR microcontrollers:*an ATmega328P runs full-tilt to generate the video signal and handle serial I/O, while an ATtiny45 handles keyboard input to avoid interrupting the ’328’s duties.*Rather than vector trace each character, a raster-scanning approach is used: the beam follows a fixed X/Y path (like a television), while modulating the Z input (beam intensity) to form an image.*The device can be connected to a PC via serial port or USB-to-TTY adapter, or directly to another microcontroller to debug serial output.
We recently showed an oscilloscope being used as a multichannel digital logic display.*The Terminalscope provides yet another use for this essential bench tool*and could nicely round out a “poor man’s” testing setup.*The schematic and full source code are available for download.
