CE432 Robotics II   Fall 2021
Tutorial 6: HW6
Humberto Arredondo
harredondoperez@fortlewis.com

HW6

1.- Introduction

In this lab we developed 6 different task using Arduinos, stepper motors, different modules, encoders, and some calculations that involved Wheatstone Bridges.


The equipment and materials used for this tutorial was: 2.- Methods and Results

For this task, we learned about Wheatstone bridge and their use to measurement resistance change in a strain gauge. we did calculations for 3 different types of Wheatstone bridges: quarter bridge, half bridge and full bridge. the sensitivity if half bridge is more than the quarter bridge and the sensitivity of full bridge is more than the quarter bridge. Calculation is show in Figure 1.





Figure 1. Hand calculations for sensitivity on quarter, half and full bridge.


 In this task, we use an Arduino uno kit to create a sketch that measures distance using the HC-SR04 ultrasonic module without the SR04.h library.



Figure 2. Demonstration of the ultrasonic sensor functioning.
For this task, we designed a pulse detector using an UNO board with an input of 5V. The challenge was to sense the pulse and deliver the same pulse 800us later. On Figure 3, from left to right, the pulse created in the function generator, the connections of the cables. The last image in the right shows the pulse created and the pulse been read with a delay of 800 us.


 

Figure 3. Pulse created the connections and results.

 In task for, we used the MPU6050, Arduino board and a buzzer to create a vibration detector. The vibrations needed to be higher than a certain threshold to trigger the buzzer.



Figure 4. Buzzer detector when there are vibrations.

 We used the joystick of Arduino kit to control the speed of the NEMA stepper motor and the Open-Smart 2.4 GHz module.



Figure 5. NEMA stepper motor speed controller using a joystick.
In this task, we analyzed the rotatory encoder and demonstrate the function.




Figure 6. Encorer and Arduino UNO.





Discussion:

The overall experience on this homework set was to be able to practice some of the techniques that we have developed over time, we realized that we can pair up a sensor or controller device to a microcontroller using the data sheets and make them work. The use of stepper motor I think is useful to understand the basics of how robotics works.