The STK500 starter kit includes 8 yellow LEDS and 8 push button switches. The LEDS and switches are connected to debug headers that are separated from the rest of the board. They can be connected to the AVR devices with the supplied 10-wire cable to the pin header of the AVR I/O ports. The figure in section "Connection of LEDs and Switches" shows how the LEDS and switches can be connected to the I/O ports header. The cables should be connected directly from the port header to the LED or switch header. The cable should not be twisted. A red wire on the cable indicates pin one. Confirm that this is connected to pin one on each of the header. The figure below shows how the LED control is implemented. This solution will give the same amount of light from the LED for all target voltages from 1.8V to 6.0V.
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