Analog vs. Digital
Arduinos are digital devices – ON or OFF. Also called discrete
Analog signals are anything that can be a full range of values. Examples?
Digital Signal | Analog Signal |
|---|---|
 |  |
Arduino does not generate true analog outputs. The instantaneous output is always 0V or 5V.
How do we generate the effect of analog using digital?
Pulse Width Modulation (PWM)
To create (mimic) an analog signal, the Arduino uses a technique called Pulse Width Modulation (PWM). By varying the duty cycle, we can mimic an “average” analog voltage
analogWrite()
C++ | Blocks |
|---|---|
Using a variable val analogWrite(pin, val); |  Note : The example above shows pin 11 being used. We can't use a variable for pin number with Blocks |
Using a constant (hard-coded) val analogWrite(3, 128); |  |
pin – refers to the OUTPUT pin (limited to pins 3, 5, 6, 9, 10, 11.) – denoted by a ~ symbol
val – 8 bit value (0 – 255).
0 => 0V
255 => 5V
