Introduction
The Raspberry Pi is a Single Board Computer (SBC) that has an enormous following online with schoolteachers, hobbyists and for many industrial applications. It was first introduced by the Raspberry Pi Foundation in the UK in 2009. Its original objective was to promote the teaching of computer science in schools. Since then it has developed through several models and generations, each with improved functionality and degree of sophistication. the RPi has moreover expanded well beyond the school and college classroom to become a large community of users creating novel applications for this powerful little computer.
If you want to learn more about the Raspberry Pi, the best place to start is at the official Raspberry Pi Foundation site and also at this link to look at the different versions currently available.
One version of the Pi that has become very popular in recent years is called the Raspberry Shake, which in fact has its own fan community and following. The Shake is essentially a seismometer in a small enclosure and is controlled by the Raspberry Pi SBC.
The seismometer is a geophone sensor, which is basically a device that converts ground motion into an electrical signal (voltage). It consists of a coil of wire wrapped around a mass that is suspended above a fixed magnet on a spring. If the mass moves in response to ground movement (say an earthquake, tremor or similar motion) it moves through the coil and generates an electrical signal.
Here’s an image of my Raspberry Shake, which has both a seismometer and an infrasound sensor:
Well over 4,000 Raspberry Pi Shake monitors are being used in a global earthquake monitoring network called the ShakeNet. This network is used by professional seismologists, citizen scientists and hobbyists alike. Many Shake devices also incorporate an Infrasound wave sensor. This is a microbarometer that can detect minute changes in atmospheric pressure.
Infrasound waves are sound waves of ultra low frequency, well below the lowest audible limits (20 Hz) of human beings. Sound waves from 20 Hz down to as low as 0.1 Hz and even lower are officially defined as infrasound. Sources of infrasound can be wide and varied. Typical examples are military aircraft, wind turbine blades, volcanoes “rumbling”, large meteors (bolides), helicopter blades, power generators, rocket launches, the list goes on and on.
This hybrid version of the Shake, that has both seismic and infrasound sensors, is called the Raspberry Pi Shake & Boom. The device is highly sensitive to any human caused sources of vibration and airflow pressure changes around my house, such as when a door opens and closes or you just walk by and create a very mild draught. So careful siting of a Shake or a Shake & Boom is very important.
The device is installed in the basement of my house and located in the quietest possible corner on a solid concrete surface, as far away as possible from sources of artificial vibration and low frequency noise. Fridges or freezers switching on and off, doors opening and closing, local traffic nearby can all generate an unwanted signal.
A live data stream in real time of my Shake & Boom in action can be found at this link for the seismic readings and at this link for the infrasound data. Alternatively you can click on Live Data Streams from the main menu.
By the way, further details of the Raspberry Shake or the Shake & Boom can be found at the official site raspberryshake.org
To paraphrase the Rock and Roll singer Jerry Lee Lewis… “There’s a whole lotta shakin’ goin’ on”!
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