LOpen logic probe detects high, low, and floating pins
LOpen is a PIC-based logic probe that fits inside a pen. It detects if a pin is at a logic ‘High’, logic “Low”, or at high impedance (floating).
project logs and tagged logic probe, LOpen, PIC12F, Project Log.
This time it’s a Logic Pen controlled by a tiny 6-pin PIC10F202. The PCB is 5 cm by 5mm so it fits just fine inside a regular ballpoint pen and have 5 leds (1 power led and 4 controllable from the PIC), over voltage protection on the probe input, reverse polarity protection using a p-fet.