Tag Archives: modulation


Audio transmission using Laser

Armand & Victor did an interesting experiment about sending audio over a laser beam. They used a 250mW diode laser, modulated its output with an audio signal, and aimed the modulated beam to a solar cell located at more than 400 meters away. The output of the solar cell is directly fed to an high power amplifier to reconstruct the audio. You wouldn’t believe the demodulated audio was surprisingly good quality.

Another IR controlled light switch

Vadim Panov’s new project is about an IR controlled light switch that operates with any RC-5 compatible TV remote. His switch is built around the¬†ATTiny2313 MCU clocked at 8MHz. The IR receiving part is designed for decoding the 36KHz modulated IR signal using the TSOP1736 device.

IR controlled light switch

IR controlled light switch

The thing I came up with at the time was a light swich for my room controlled over an IR remote from TV. Remote that I had used RC-5 protocol, hence the firmware is suited for any RC-5 compatible remote.
Everyone is familiar to the everliving problem with switching the lights off in your room before going to bed and stumbling back across the room. The IR switch I describe here solves that problem, and I can definitely tell that this project was a success – I am still using it with no regret.