PIC superprobe project gained its popularity because of simplicity of design. It uses very few widely accessible electronic components.

This small tool can serve as:

• Logic probe - for detecting High or Low voltage level;
• Logic pulser - for generating pulses with various rates;
• Event counter - for frequency counting;
• Voltmetter - for measuring voltages up to 5V;
• Diode junction voltage probe - for displaying diode voltage drop ;
• Capacitance meter - for measuring capacitors from 0.01uF to 100uF;
• Signal generator - for generating 500Hz square wave signal;
• Video patter generator - for generating NTSC video frames;
• ASCII generator - for generating Letter from A to Z leaded by cr/lf code;
• Midi note generator;
• R/C servo pulses;
• Square wave generator - from 1 to 9999Hz;
• Random number generator;
• IR LED signal generator - allows to send 38kHz signals during IR led testing;
• PWM generator;

And all that functionality is controlled by two buttons while information is displayed on four 7 segment LED displays. I’d say this is a “must have” tool. Source code of project is here. Also check out the Hall Of Fame of all reproductions of this nice tool.