Motorbike Alarm

The principle is a very simple one: once the bike has been set on its stand, three carefully-positioned mercury switches give position information to a microcontroller, which it then memorizes when it is powered up. The surveillance starts right away; any change in the bike’s position will upset the configuration of the three switches and set off the alarm.

The unit described is intended for analysing signals that are transmitted via a MIDI link. It enables the digital information to be made visible and, if necessary, to be corrected. It can also be used to map the entire range of signal-determining data of a synthesizer.

Musicians appear to have a predilection for connections, as witness the myriads of cables that can be found around and on the stage when a pop concert is taking place. The multiplexor described in this article enables interconnecting of a number of MIDI instruments quickly and tidily.