i am trying to interface ad5933 with dspic33ep256mu806. my frequency generation is working properly,while capturing no results is shown in read bytes.... i attached my code along with this post.. please check and help!!!!!
We tried to compare your code to the example code for the AD5933.
We noticed that the example code includes this function for reading the registers of the AD5933.
You can try to make one for your ad5933reg_byte_read function.
i checked the d0 ststus and read the registers, i have connected a resistor(100k) across v0 and vin. but in imaginary register some values is appearing except all zero. why it is so???
Also, connect a 100k resistor across pin 4 and 5 as a feedback resistor then try to read the registers again.
i did that... but i am confused in my seep function... have u checked my code??
i wrote a new code... now i have a problem wit reading the datas from real and imaginary registers.. i am confused whether my code is right?? please check and tell me the problem
ya. that was the problem!! i got the result!! Thankyou!!..... i have a doubt... my rfb is 100k and when i am measuring rcal 100k and above its works perfectly... but when i am measuring below 100k its not working properly.... y it is so???
what is the capacitor range which i can measure with this ic???
Using an Rfb of 100k, the settings on your program and the first formula from page 5 of http://www.analog.com/media/en/technical-documentation/application-notes/AN-1252.pdf, we can obtain Zmin.
Substituting the values of the variables in the equation, we will get 80k for Zmin. Then using an Rcal of 100k and the second formula, we can obtain Zmax.
Substituting the obtained Zmin and the value of Rcal, we will get 220k for Zmax. The impedance range that can be measured accurately with this setting would only be from 80k to 220k.
Using the same settings, the impedance range of capacitors that can be measure would also be from 80k to 220k. With your frequency sweep ranging from 30kHz to 40kHz and using the formula,
A capacitor range of 24.11pF to 49.74pF can be measured.
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