A potentiometer can vary between 0v-5v and we conected that to the sensor value pin. then the arduino changes the sensorvalue varible to change blink speed
Pros- you can manually change the range from light to dark.
Cons- the manualTune cannot go from zero to five volts so the light cannot be completely dark
Pros- the light can turn completly of becuse the auto tune adjusts the brightness of the led.
Cons-