Bluetooth

https://www.youtube.com/watch?v=1I1vxu5qIUM

Transmit an electromagnetic wave (binary) with different wavelength

eg: 121mm = 1 124mm = 0

the waves send in all directions

Bluetooth range: 2.4835GHz - 2.4GHz

Divided in different sections (79 channels), each section has a pair of wavelengths representing 0 and 1

the bluetooth range is shared with some other device like a microwave oven

like the power of a microwave oven is too large for bluetooth.

it may destroy the bluetooth device if you put them inside the microwave oven (danger)

Data Integrity #

Packet #

• Access Codes (72 bits)
• Header (54bits)
• Payload (vary, depends on the function)

Frequency Hopping #

Two bluetooth devices will have a set of channels to send data

They will change the channels frequently

Error Detection #

Noise Filtering #

Data Transmit #

Frequency Shift Keying #

carrier wave adjusts the wavelength to send 0 and 1

Phase Shift Keying #

constant wavelength and attitude

use the wave function to determine 0 and 1 (like sin x = 0, cos x = 1, instead of A sin x and B sin X)