mihir.1990
Newbie level 5
I have interfaced CS5460 with 89v51rd2 and i am getting the rms and instantaneous values and have displayed it on my lcd. I have done the offset and gain calibration too.
Now the problem is that my rms value which i am getting is always the double of instantaneous value.
So now when differential voltage applied is 0mv i am getting 0000 as the reading.
Then when i reach 125 mv the instantaneous voltage beocomes ~4200000 counts but rms goes to 8388608 counts that is full scale. Again when voltage is increased above 125mv the rms reading increases from zero and again when voltage reaches 250mv the rms reading reads 8388607 ie full scale.
On the other hand instantaneous gives proper linearity ie
1) zero counts on 0 mv
2) ~ 4200000 counts on 125 mv ie mid range
3) 8388607 max counts on max voltage ie 250mv.
i need the same linearity with rms values too.
please help
Now the problem is that my rms value which i am getting is always the double of instantaneous value.
So now when differential voltage applied is 0mv i am getting 0000 as the reading.
Then when i reach 125 mv the instantaneous voltage beocomes ~4200000 counts but rms goes to 8388608 counts that is full scale. Again when voltage is increased above 125mv the rms reading increases from zero and again when voltage reaches 250mv the rms reading reads 8388607 ie full scale.
On the other hand instantaneous gives proper linearity ie
1) zero counts on 0 mv
2) ~ 4200000 counts on 125 mv ie mid range
3) 8388607 max counts on max voltage ie 250mv.
i need the same linearity with rms values too.
please help
