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.
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 )
- LCD I2C
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 )
1.)The details of the calibration and the reason why we need it is explained in page 17 of the datasheet. It has something to do with gain factor variation over frequency.
2.)Skim through page 15 of the datasheet. It is explained here how to configure the device to run a frequency sweep and measure impedance. The controls are done via I2C.
3.)I've searched the net and fortunately I found this. AD5933 Arduino Library Functions · WuMRC/drive Wiki · GitHub. I hope this could help.
Thanks mister Louijie for the information and the link, because it's very helpful.
i noticed this code from you link suggestion
autoimpedance/measureImpedance.ino at master · open-ephys/autoimpedance · GitHub
it may be an important code too, i will give it a try too,
i will practice and see the results, thanks again,
I am wondering if you were able to complete the project. It will be a huge help for me if you code share the project.
I don't know if this is still applicable but I wrote an Arduino library for the CN0349, which contains the AD5933.