THE HISTORY OF BLUETOOTH
Since the 60s electronic engineers have been looking for the best wireless solutions. However, a device with standard features was missing, on the platform of which a series of products could be developed with a kind of compatibility, international approvals, low battery power consumption, and most important of all, total immunity from disturbances and interferences.
We can say that there was a huge void to fill. But no one had yet thought about designing and standardizing a wireless device let's say 'universal'. This void has been largely filled by the BLUETOOTH system. We can say that today we have over a billion BLUETOOTH-based radio devices in the world.
BLUETOOTH was born as a short-distance radio communication development by Nils Rydbeck. This person, the systems developer at ERICSSON, had the vision and concreteness to carry out the project with a team of very efficient developers. The initial idea was to design wireless headphones, but the team saw an immense opportunity along the way. Let's not go into the details of the official invention and the various inventors involved in the project. We can say that today technology has defined itself and everything is organized and maintained by the Bluetooth Special Interest Group (SIG).
Initially, groups such as Nokia, Intel, IBM Ericsson, and others, have started to adopt the system called BLUETOOH. In 2001 IBM presented the terminal with integrated BLUETOOTH and ERICSSON presented its own T39 mobile phone equipped with BLUETOOTH. To date, the consortium that joins Bluetooth has hundreds of important companies.
The name adopted for this technology is a little unusual. It refers to a Scandinavian leader King Harald Bluetooth who brought together populations of different languages. BLUETOOTH is in fact a system for communicating between different devices. Not bad the idea of the name introduced by the developer in INTEL Jim Kardach. Without going into details, let's focus on the key features that have enabled the exponential development of electronic boards based on BLUETOOTH.
- low current consumption during operation (15-25ma)
- operating voltage compatible with market batteries (2-4v)
- sleep condition requiring only a few microamps
- easy connection and coupling to it devices
- easy connection and pairing to mobile phones
- audio data transmission with 24bit resolution at 96khz
- digital data transmission @ 1 megabit per second
- built in antenna with size of about 15mmx20mmx2mm
- Bluetooth modules of easy interface to microprocessors
- communication by UART with MCU and smartphone
- easily configurable using Windows or apple os
- supports audio codec and DSP processing
- use the UHF band included between 2.4 and 2.485 giga Hz
- capacity of the development consortium beyond the international standards
- retroactive compatibility of new developed versions
- point to point communications and networking
- presence on the market of easily interfaceable modules
- typical transmission power up to 15 dbm (about 30milliw)
- programmable output power (0.5 up to 100 meters)
- sensibility up to -90 dbm (tens of picowatt)
- package data transmission technology in 40..79 shared channels
- ideal solution to replace data communication or state on wire
- operating principle type master-slave automatically reconfigurable
- cost of the radio modules included between € 2 and € 9
- easy availability on the market, huge product offer
