In this example RB4, RB5 and RD0 pins are used as digital output pins. These pins can be used as general purpose output pins (GPIO pins) to drive LED diode directly or as TTL level signal output. Complete source code programmed in dsPic C30 compiler with MPLAB project files is provided and every line has comments with detailed explanation.
One of the most remarkable and novel discoveries in the last 400 years was electricity. We might ask, “Has electricity been around that long?” The answer is yes, and perhaps much longer, but its practical use has only been at our disposal since the mid to late 1800s, and in a limited way at first. One of the earliest public works gaining attention was enlightening the 1893 Chicago’s World Columbia Exposition with 250,000 light bulbs, and illuminating a bridge over the river Seine during the 1900 World Fair in Paris.
Here is example that is complete project with step by step guide that will show you how to use GPIO pins on ATmega8535.
When you start program use CodeWizardAVR to generate basic program structure.
In our case we used ATmega8535 so we will choose that modem from Chip tab in wizard window.
For frequency chose correct frequency that is used (external xtal, calibrated internal RC oscillator..).
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.