digital data transmission on analog signal, fm 108mhz

Status
Not open for further replies.
D

devil6600

Full Member level 5
Joined
Nov 15, 2008
Messages
250
Helped
7
Reputation
14
Reaction score
7
Trophy points
1,298
Visit site
Activity points
2,931
hello,

i have microcontroller (pic32) connected with accelerometer and mic, microcontroller will be connected to accelerometer using I2C and adc for mic, i want to transmit all the data using fm 108mhz, how to do it?
can i use the below scheme?

uC---->digital to analog--->Transmitter)))) --> Receiver-->analog to digital--->uC

how to make digital to analog conversion? and how to calculate if 108mhz have enough bandwidth for this transmission.

thanks
 

First of all you must split your analogue base band into two, one part is the mic. the other the output from the accelerometer. you must decide what part of the base band to give to each signal. i.e. the mic could be "telephone" quality 300-3KHZ or Hi-fi, 20 - 20 KHz. The output from the accelerometer could FM a pilot carrier at 10 KHZ, or 40 KHZ. Mix the signals and apply to your 108 MHZ FM modulator. At the receiver end, filter the output from the FM demodulator to recover the two signals. Demodulate the pilot tone to recover the accelerometer output.
Frank
 

Why analog modulation, why 108 MHz? You are not allowed to use the FM broadcast frequency for data or private audio transmission, except for very short distance at µW power, e.g. to feed your radio with recorded sound.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…