... the digital pins ON and OFF at a very high frequency creating a dummy analog signal. And there are 6 digital pins on UNO that supports this behavior- with a "~" symbol next to them (like 3, 5, 6, 9, 10, 11) When you use analogWrite(pin, value), you're controlling the Duty cycle of the PWM signal A value of 0 means the pin is off all the time. A value of 255 means the pin is on all the time. Values in between control how long the pin stays on during each cycle, effectively simulating an analog voltage between 0 and 5V. So analogWrite function has nothing ...