garygothic
New Member
Hi. I need help from experts. I'm doing a project on reading analogue voltage humidity sensor (**broken link removed**) using PIC16F917 (datasheet) and then showing the converted value on a LCD. I'm using the built in ADC in the PIC for the value conversion. The problem is I cannot get the accurate reading from the PIC. A quick check up on the Humidity sensor datasheet,I found that the sensor's maximum settling time is 70ms. Meanwhile the AD acquisition time (page 183) Tacq with 10kHz source of impedance and 50degreesC temperature is 4.67us. So I suspect the causes of the inaccurate reading are because of high possible transient amplitude and slow settling time. I have read somewhere that I need to build an RC circuit in between the output voltage,Vout, of humidity sensor and input of the ADC in order to rectify this problems. Now, my problem is I do not know how to build one and the theories behind it. I just know the basic design of RC circuit: **broken link removed**.
What value of resistor and capacitance should I used in my RC circuit?![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
What value of resistor and capacitance should I used in my RC circuit?