AFSK 1200 Modem Based on PIC16C620

The concept involves using infrared light that is reflected by a disc, except for a dark red line. The sensor receives the reflected light, allowing the Arduino to track the number of revolutions. The infrared sensor is tuned to...

The prototype was successfully assembled on a breadboard and subsequently built on a piece of Radio Shack protoboard for field use. The assembly process took only a couple of hours, and it functioned correctly on the first attempt. This...

A PIC16x84 processor can be utilized to generate a PSK31 or FSK31 signal. This signal may serve various purposes, including beacon transmissions, telemetry, experimentation, or QSOs, though the latter may involve some quirks. The PSK transmitter was initially designed...

A replacement remote control system for an electric garage door was constructed after the original remote failed multiple times. Although the old remote could have been repaired, it was 35 years old and not particularly enjoyable to use. The...

Various circuit variations have been explored, including a standalone preamp, headphone amplifier, replacements for the 321/729 circuits, and a potential active crossover, depending on demand. There has been significant interest in these designs, and the bootstrap buffer preamp is...

This circuit features automatic exit and entry delays, a timed bell cut-off, and a system reset. It accommodates both normally-open and normally-closed switches, making it compatible with various input devices such as pressure mats, magnetic reed contacts, foil tape,...