When designing active filter for your project you will need software tools to help you get right component values as well as minimize time spent designing. Tool that will hel you automate this process is FilterLab from microchip.
FilterLab® is an innovative software tool that simplifies active filter design. Available at no cost, the FilterLab® active filter software design tool provides full schematic diagrams of the filter circuit with component values and displays the frequency response.
Often you will need to filter signal to adjust it for ADC measurement or remove noise from measured signal. Analog filters are right way to do this. Here is some basic information about analog filter design terms used when designing filters. Active filters give better performance since they can be adjusted not to attenuate signal.
When working with GPIO (general purpose input/output) pins of microcontroller you must be aware of few things. Some people think it is enough to know how to program but often you MUST know few basic things about hardware so that you can prevent hardware damage as well as to make sure that device will work correctly.
Here are basic you will need about microcontroller pins.
Here is answer!
You need microcontroller, you should buy one. I recommend ATmega8, ATmega16 or ATmega8535 because they have all integrated peripherals that you will need to learn how to use it and have numerous examples online.