CGA monitors may not be an amazing technological advance these days, but they can generally be found very cheaply. Additionally, they have a DB-9 connector and work off of TTL ranges (0-5VDC) makin… ...

An Arduino Uno provides the processing power and drives the serial monitor. A joystick and a Hitachi H48C accelerometer are mounted on a breadboard and wired to the Uno.

Serial Port Monitor from Eltima. The Serial Port Monitor software tool from Eltima Software is, in fact, a professional port sniffer and analyzer system utility good for RS232/RS422/RS485 port ...

If you want to DIY solution to your energy consumption, here's how modders created a home energy monitor from an Arduino, some wiring, and a little custom code.