Week 9. Input devices

Group assignment

During this week’s group assignment, we used an oscilloscope to measure the analog levels and digital signals of the input devices connected to our PCB.

In the first experiment, we applied voltage (V) to the analog pin of a variable resistor sensor. By rotating it, we observed that the waveform on the screen increased and decreased proportionally to the rotation. In the case of an analog signal, the variations change smoothly.

In the second experiment, we applied voltage to the digital pin of a photoresistor. When we turned the light on and off over it, we observed sharp changes on the oscilloscope screen.

Then, by applying voltage to the analog pin and repeating the same light on/off process, we observed smooth variations on the oscilloscope, similar to the analog case.

Conclusion

From these experiments, we can conclude that analog and digital signals behave differently when observed on an oscilloscope. Analog signals change smoothly and continuously, reflecting gradual variations in input (such as rotation or light intensity). In contrast, digital signals switch abruptly between discrete levels (high and low), resulting in sharp transitions on the screen. This demonstrates the fundamental difference between analog and digital signal processing in electronic systems.