Sensors & Actuators on Raspberry Pi

These instructions will show you how a Raspberry Pi can interact with the physical world using sensors and actuators.
This software and hardware allows you to collect data from sensors and send signals to actuators by Python programs running on a Raspberry Pi.

More information on the GrovePi+ system used is available online.
This system allows you to collect data from devices connected to your Raspberry Pi-such as peripherals and connected sensors that measure light level, sound level, temperature level, humidity leve and more.

After completing this assignment you will be able to:

1. Investigate sensors and actuators
2. Run Python programs on a Raspberry Pi that communicate with sensors and actuators
3. Discuss uses of Raspberry Pi/Grove Pi devices to solve problems and address opportunities

You are expected to have a working knowledge of SBC hardware and software.
If you do not understand how to use an item, perform a Google Search, refer to the WSU Technology Knowledge Base,  ask a teaching assistant, or ask the instructor.

1. These steps are performed on the Raspberry Pi.
2. Each IoT workstation contains a Raspberry Pi, Grove Pi+ data acquistion board and 10 sensors and actuators.
   Python programs have been written that control these devices-physical connections, data gathering, data processing, data presentation and data storage, if required.
3. Make sure that the Raspberry Pi is powered on.
   Then inspect the GrovePi board to make sure it is also powered on-the green LED in the bottom center of the board will be lit.
   Note-if the GrovePi board Red LED reset light is illuminated, you must shutdown the Raspberry Pi, turn off the power, wait five seconds and then turn the power on again.
   

   GrovePi with Red Reset light on
   

4. Familiarize yourself with the available sensors and actuators depicted below.
   

   GrovePi with Sensors and Actuators-on top of Raspberry Pi
   

5. Review the GrovePi Configuration that details how the sensors and actuators are physically connected.
6. On the desktop, right-click the 'Grove LED Bar' icon.
   
   Choose 'Text Editor'
   
7. Mousepad opens and displays a configuration file containing the path to the xLED_bar.py file
8. Open a Terminal Window, enter python and the path to the Python file:
   python /home/pi/Desktop/IoT_Files/xLED_bar.py
   Press Enter and the program will execute, and illuminate the LED bar segments.
9. Alternatively, double-click the Grove LED Bar icon on the desktop and choose 'Execute in Terminal'.
10. To view the python program, open 'File Manager' to the path indicated above, find the file xLED_bar.py, right click it and choose 'Text Editor' .
    Examine the program code.
    

    LED Bar test on desktop
    

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1. These steps are performed on your Raspberry Pi.
2. Using the skills learned, examine the program behind the Grove IoT icon on the desktop.
   Hint: it is connected to the program 'xSystemTest.py'
   
   
3. The program xSystemTest.py is much more complex.
   It is designed to test the proper functioning of all the sensors, actuators and the Raspberry Pi sound system.
4. Run the program xSystemTest.py
   Note-this program is interactive, follow the prompts on the screen.
   Note-the program will read the test results aloud, if not troubleshoot the Raspberry Pi sound system.
5. When done, the program appends the results to SystemTest.txt on the desktop.
   Open the file, scroll to the end.
   

These steps are done on the Raspberry Pi, or on your laptop using VNC.

1. Take a screenshot of the last part of the SystemTest.txt, displaying the light level and current date.
   Note: this can be done using the Snipping Tool if you are running VNC, or use the scrot command if you are connected to the Raspberry Pi with a keyboard and mouse.

   system test output
   

2. On your laptop save the screenshot as "IOT10" in your ' ' folder.
   

Submit to the appropriate D2L Assignment folder a screenshot that documents your work.

Based on your experience in this exercise, consider the value of IoT devices for organizations, especially those needing to collect information.
Think about what type of problems a Raspberry Pi equipped with sensors and actuators could solve, and whether it could be cost-effective.
Businesses are deploying IoT 'solutions'-how can sensor equipped Raspberry Pis support or automate these efforts?

References:
Grove Pi:  Grove Pi Wiki
Grove Hat:  Rasberry Pi Weekly