9. Input Devices: Amalia, Elle¶
- Probe an input device(s)’s analog levels and digital signals
- Document your work on the group work page and reflect on your individual page what you learned
Digital Signals (Elle Hahn)¶
Push Button¶
For our digital signal input, we chose to use a push button. The functionality is straightforward: when the button is pressed, the LED turns on, and when the button is released, the LED turns off. This setup demonstrates a basic digital high (1) and low (0) signal system. On the oscilloscope, this behavior is clearly visible — when the button is pressed, the signal line jumps to a higher voltage level, indicating a high state. When the button is not pressed, the line returns to a lower voltage level, indicating a low state.
This kind of setup is useful in many real-world applications where user input or interaction is needed. For example, push buttons are commonly used in electronic devices, control panels, and user interfaces to trigger specific functions. Monitoring the signal with an oscilloscope helps verify that the circuit is responding correctly to input, and it also helps with troubleshooting or optimizing response time. Overall, it’s a simple but effective way to demonstrate how digital signals can be used to control outputs in a circuit.
Analog Levels (Amalia Bordoloi)¶
Photoresistor¶
We decided to ask for help from Mr. Dubick. He recommended that we try to use the oscilloscope to measure resistance with the photoresistor. A photoresistor, also known as a light-dependent resistor (LDR), is a type of resistor whose resistance decreases as the intensity of light falling on it increases. In other words, it is a light-sensitive component that changes its resistance in response to light levels. Photoresistors can be used in projects like nightlights.
As demonstrated in the video above, when the hand moves closer to the sensor, the resistance decreases, causing the oscilloscope line to shift. Conversely, as the hand moves further away, the resistance increases, and the oscilloscope line moves in the opposite direction. When testing the photoresistor, we initally ran into an errorbecause the oscilloscope was connected to the voltage instead of ground, which held the line constant, but once we figured that out, it worked very effectively.