Just like a PC’s USB port, the serial port on a PC can also in some cases serve as a power supply. A USB port can provide as much as 500 mA at 5V, but a serial port provides less power. Even with the ...

However, many microcontrollers have a serial port — even one with a USB converter built-in — but fewer have full-blown USB hardware. Even the ones that do are often at odds with strange ...

Many industrial and instrumentationsystems need to measure theduration of pulse inputs, such as frequencyfrom rotational-speed sensors,gating and strobe pulses from externalsystems, and PWM ...

Anyway, I was assuming that I'd have to go out of the serial port and into a microcontroller of some kind to turn the bitstream into a raw voltage corresponding to percentage of processor usage.

So I'm trying to detect through Visual Basic 6.0 when a voltage change occurs on one of the pins of the serial/parallel port. The whole thing is pretty simple; no data transfer/handshaking/etc ...