2. Definition
Bluetooth is a specification (IEEE 802.15.1) for the use
of low-power radio communications to link phones,
computers and other network devices over short
distances without wires.
The name Bluetooth is borrowed from Harald Bluetooth,
a king in Denmark more than 1,000 years ago.
First specification released in July 1999
5. General Specification
Bluetooth technology was designed primarily to support
simple wireless networking of personal consumer devices
and peripherals, including cell phones, and wireless headsets.
Wireless signals transmitted with Bluetooth cover short
distances, typically up to 10 meters.
Bluetooth devices generally communicate at less than 1 Mbps.
Bluetooth networks feature a dynamic topology called
a piconet or personal area networks (PAN), up to 8 devices
6. Radio Specification
• The Bluetooth system is operating in the 2.4 GHz ISM
(Industrial Scientific Medicine) band. The regulatory
range of this frequency band is 2.400 – 2.4835 GHz.
• The Bluetooth radio accomplishes spectrum spreading by
in 79 hops displaced by 1 MHz.
• Radio modulation uses GFSK.
7. Bluetooth vs. Wi-Fi
Although the Bluetooth standard utilizes the same
2.4GHz range as Wi-Fi, Bluetooth technology is not a
suitable Wi-Fi replacement.
Compared to Wi-Fi, Bluetooth networking is:
o Much slower
o A bit more limited in range
o Supports many fewer devices.
8. Bluetooth Classes
Three classes of Bluetooth devices
o Class 3 radios: have a range of up to 1 meter
o Class 2 radios: most commonly found in mobile devices,
have a range of 10 meters
o Class 1 radios: used primarily in industrial use cases, have
a range of 100 meters.
9. Link Manager Protocol (LMP)
Responsible for link set-up between devices, including
security functions :
o Authentication
o Encryption
Pairing:
o Using a shared secret (PIN), exchange random number to
form key.
13. AT Commands
AT Command Actions Return
AT Testing the connection OK
AT+BAUDx Changing the default baud rate OKbaudrate
AT+NAMEname Changing default name OKname
AT+PINpin Changing default password OKpin
14. Lab
BT to PC as Serial port connection
Test AT - Commands
Check outputs
BT to PIC
Test AT - Commands
Application blinking LED number + LCD
PC to BT by software
Moving car
Mobile to PIC by BT
MCU App
Moving car app, Controller app, BT SPP app
Check output by LCD or PC