AD5933 with Arduino

Hi everybody,

I'm new here, and I would like to have some informations about a project we are trying to make for our school.

it's about interfacing an AD5933 chip, with an Arduino Uno to make a body Impedance measurement and then, show the information on an I2C Lcd.

this Bioimpedance will be done ( i hope ) on bedridden people, therefore it has to be an mobile measurement.

Why measure impedance ?  because it reflects the water volume of the body witch gives information about the mass and/or fat concentration, and also the phase witch reflects the health of the body cells.

in fact,

currant at a high frequency gives an impedance witch reflects the extracellular volume

currant at a low frequency gives an impedance witch reflects the intracellular volume

and both give us the total volume of the body

so our purpose is to measure the impedance with at least 2 frequency and to measure the phase

then convert this information with dietetic formulas to have concrete information for a future display.

my general components are :

- Arduino Uno

- AD5933 ( not the EVAL juste the chip )


so i would like to know some information about :


- How to calibrate and why a need of calibration ? 

- How can i change the currant frequency ?  ( because the ad5933 has a fixed frequency but programmable via Arduino ?  )

- is there an Arduino library witch has some methods for the impedance measurements ?

( sorry for the incorrect English, I'm from Belgium )

thanks friends