This running LED or LED chaser is a good project for beginners in the microcontroller technology. It is easy to build, and the assembler program code can be easily adapted. This running LED light has 15 red 3mm LED’s. The 15 outputs of ports B and D are used to drive the leds.
The LED’s light up in a pattern that can be made in the program code, the LEDs run back and forth. With a push button you can select another pattern at which the LEDs runs. There are three running LED patterns which you can run: with one led, three leds and five leds.
There are also 4 patterns with fading LEDs:
Fading out from the center to the side
Fading out from the side to the center
Fading out from left ot right
Fading out from right to left.
The project uses the ATTiny2313 micrcontroller but the ATTiny2313 can also be used.The AVR port can draw 20mA current so you only have to place a resitor at the port of the AVR to limit the current to 20mA. The LEDs are connected to ground so when the output of the port is high the LED will go on.
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