Dear reader,
Lets say the experiment i am doing is divided into 4 parts like any other measurement device principle: 1) the sensing element, 2)The signal conditioning element 3)signal processing element and software 4)data presentation element.
The sensing element in my experiment is the capacitive co-axial probe that operates using capacitive principle,As you immerse the probe in the water, the di-electric medium in between the 2 electrodes increase further increasing the capacitance. I have connected this probe to a frequency oscillator designed using a 555 timer in astable mode. The sensed signal is enhanced by this oscillator into a frequency domain. The frequency of the signal decreases as capacitance of the probe increases.WE have the relation as,
f =1/(2*pi*(LC)^1/2) for an LC circuit
f= 1.44/{(R1+2R2) C} for an RC circuit n this is my circuit and i have designed keeping my own values.
hence, when the probe is immersed in the water at0 cm scale, the frequency received is 872khz,further more as i went on taking the reading,the final point i needed to take is at 30 cm scaling and i received 435khz. So there is a frequency range of 400khz to 900khz.now i need to feed this signal to the ATmega16 controller. Its bit tricky at this point. The data sheet for atmega16 can be found in the internet. I know frequency and time is inversely related and i need to use timers .how ever i am stuck at this point of writing the codes,if anyone could help ma,then please i ask for it ,your effort,guidance and sample codes could lead to my progress.
thanking you