Analog VS. Digital SignalsAnalog Signals
are used to describe voltage levels from an instrument or device that is continuous. Unlike Digital Signals
where the output is categorized into two “threshold” values (on / off) an analog signal’s output is applicable within a range of voltages. A great example would be an optical sensor.
Let’s say the optical sensor we have outputs higher voltage as the light level rises. The range of voltage output goes from 0v (dark), to 5v (extremely bright) Since this rise reflects the amount of light seen by the sensor, we can use the voltage level to determine the light levels within a room. If we want to know the level of light to varying degrees within the room, we would want to interpret the sensor as an analog one - taking into account where the output falls on the 0 to 5v scale. In contrast, If all we cared about was to determine whether the room was really bright or totally dark (say if the lights were on or off) - we would want to interpret the sensor as a “digital” output. The digital output interpretation would look for values above or below certain levels - and in this case we could say:
If the voltage is below 1v, then the lights are off, and if the voltage is above 4v, then the lights are on.
Analog voltages are used in sensors that generate varying levels of feedback where a simple “on / off” value is not descriptive enough. Examples include speed sensors, pressure sensors, light sensors, and many more. Analog sensors are more susceptible to noise, however they contain much more data than digital sensors because theoretically their Resolution