Homework 1, Polling vs Interrupts .

Short Description:

Goals

• Demonstrated your ability to write code for the Arduino
• Demonstrated your ability to use interrupts
• Experienced and explained the difference between interrupts and polling

Formal Description

• Using the code discussed in class explore the difference between interrupt and polling driven input. To do this
  • Build/modify a computational intensive program on the Arduino Nano. Perform a baseline test to determine the time required to perform the task
    • It would be reasonable to conduct the experiment n times, where n ≥ 10 and calculate the average time to perform the task.
  • Add a polling driven method to check for input.
    • This can be implemented at multiple places in the program, so try at least two different locations for checking for input.
      • In one, add a test where the computation loop is not changed.
      • In at least one, add a test test where the computation loop is changed.
        • Consider testing every iteraion of the loop
        • Consider testing for input every k iteraions of the loop, where k is of different sizes.
          • In the end, can you find a resonable value for k?
          • Consider what you are trying to balance.
    • Provide an input routine that counts the number of times the input was received
  • Conduct n (from above) trials for each configuration
    • For each trial record
      • The modified computation time.
      • The number of inputs actually received.
    • Do your best to try to provide a set of uniform button presses.
      • You may perform actual button presses or you may use a timer to simulate button presses.
  • Re-implement the code using interrupt driven input.
    • Duplicate the experiment described above.
• Write a report in the IMRD format discussing your results
  • The introduction section should discuss the investigation of polling vs interrupts, including a definition of each.
  • The methods section should discuss the above criteria as well as the implementation your have selected. It is appropriate to include code snippets.
    • For example, you should discuss where you added the polling requests in each case.
    • You should describe how you tried to provide uniform button presses
  • In the results section, present your data and findings. This is just a data section, no interpretation should be present.
  • In the discussion section, discuss your results and any future investigations you might wish to perform.

Required Files

• A zip or tar file containing
  • The two different versions of the code. For the multiple different polling experiments, please just comment out or deactivate the unused configuration(s).
  • A word document containing your report.

Submission