I am trying to use a capacitive humidity sensor (HCH-1000-002) with PIC16F690. I have read about 2 different circuits to detect the capacitance of the humidity sensor. One uses Timer 555 (NE555S-13 – see Figure 1) and the other uses resistors and the comparator in the Pic (see Figure 2)
Figure 1
Figure 2
1) Which is the best circuit?
2) How do I calculate the capacitance?
Figure 1
Figure 2
1) Which is the best circuit?
2) How do I calculate the capacitance?