# Overview of Group Assigment 1. Probe an input device(s)'s analog and digital signals ## Foreword Our team had referenced <br> <br> 1. [FabAcademy SP 2020 Group assignment](http://fabacademy.org/2020/labs/singapore/group.assignments/assignment07.html) <br> ## Group assignment: To learn about how input devices work, we decided to take a low-level approach. ### Analog Signals We used a potentiometer as our input device, and measured the output signals directly. No code is requried for this set up, and as we rotate the potentiometer's knob, we can directly see the values being changed at the data line via an oscilloscope. <img src="./potentiometer_diagram.jpg" width="240" /> Image above shows how we have hooked the Potentiometer up with a power supply set at 5V output. <br/> <img src="./potentiometer.jpeg" width="480" /> Image above shows us measuring the value at the dataline using a multimeter, which we expect to be anywhere between 0-5V. <br/> <img src="./Wiring_diagram_oscilloscope.jpg" width="480" /> Image above shows our wiring diagram to an oscilloscope, power supply at 5V output and signal line connected to the oscilloscope. <br/> <video width="480" controls> <source src="./Potentiometer2.mp4" type="video/mp4"> Your browser does not support the video tag. </video> Video above shows us viewing the measurements via an oscilloscope. The positive side of the probe is connected to the data line and the negative side of the probe is connected to the ground of the potentiometer. <br/> ### Digital Signals We used a push button as our input device, and measured the output signals directly. Similar to Analog Signals, no code is required for this setup, as we push the button, we are expecting a step from voltage low to voltage high. Having 2 discrete outputs makes the push button a digital input device. <img src="./button_internal_wiring.jpg" width="480"/> We first looked up how a push button works internally, credits to [arduinogetstarted.com](https://arduinogetstarted.com/tutorials/arduino-button) <video width="480" controls> <source src="./push_button_grp_assignment.mp4" type="video/mp4"> Your browser does not support the video tag. </video> Based on the circuit diagram above, we physically hooked the wires on a breadboard. <img src="./button_wiring_physical.jpg" width="480" /> Then, we measured the output voltage as per the circuit diagram. If we were to hook the button up to a microcontroller, we would hook the orange wire to a physical pin, and check the voltage levels. If the voltage level is close to 5V then it is logic high; if it is close to 0V then it is logic low. <video width="480" controls> <source src="./physical_push_grp_assignment.mp4" type="video/mp4"> Your browser does not support the video tag. </video>