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11. Input devices

▶ Group assignment

  • Probe an input device(s)’s analog and digital signals

In the beginning, let’s know the difference between Analog and Digital signals

What is a Signal?

The Similarly signal is a way of communicating by sending information from one system to other system. In other words signal is a function that represents information or data.

Signals which are

1- Signal which are Continuous as time varying in nature are analog signals.

2- Signal which are discrete are called digital signals.

Analog Signals

Analog signal is a form of electrical energy (voltage, current or electromagnetic power) for which there is a linear relationship between electrical quantity and the value that the signal represents.

Digital Signals

The signal, whose amplitude takes only limited values is called Digital signal. and the are discrete, they contain only distinct values.

Measure the LDR Sensor

By using the oscilloscope to measure analog levels from the sensor and digital signals

To do that I’m using the oscilloscope to observe how the change of the natural lighting will affect the voltage sent to the Board.

you can see in the picture If I leave the LDR observe the neutral light the voltage is hight

and If I cover the LDR The voltage will reduce so the line in the oscilloscope screen will go down


From Arduino, I sent a digital signal ,An digital signal is usually in the form of square wave. In this case, it shows H = 10010101 from left to right. Upper lines mean 1, and lower lines mean 0.

From Arduino, I sent an Analog signal, by using any sensor here I try with LDR.


Last update: July 25, 2022