This part uses both the LED screen as well as the two switches. The two switches are connected to input channels numbered 0 and 1.
* Switch #0 is connected to channel #0, and is called the DIRECTION switch.
* Switch #1 is connected to channel #1 and is called the SPEED switch.
For this part, your program should operate as described above with the following additions:
* When the SPEED switch is off, the display should be updated once every second. When the SPEED switch is on, the display should be updated once every 0.5 seconds.
* When the DIRECTION switch is off, the message should scroll to the left (as in the required part above). When the DIRECTION switch is on, the display should scroll to the right. When scrolling to the right, the operation is simply the reverse of scrolling to the left.
Using Simulator / Hardware Module
The simulator will allow you to test your program without the need for the actual hardware module. To access the configuration for this problem, you should specify a config_type of 4, when calling the init_daq function. You will find the simulator under the "Part 2 - Lecture contents" page on your WebCT Vista home.
If you are working in a TA-supervised lab, you will be able to use the actual hardware module if you wish so. The hardware module also has 2 switches and 8 LED displays arranged in a row as an LED screen. To use the hardware module, you should specify a config_type of 0, when calling the init_daq function. Note that you will only have access to the hardware module while a TA is present in the lab.
Algorithm development and coding
Carefully read the Problem Statement above and try to decompose the problem into smaller manageable parts.
Your program should include at least the main and scroll_message functions. Your program should follow the same basic structure of the in-class examples, i.e. the main function should perform the necessary initialization and then call the scroll_message function.
The scroll_message function (and any additional functions you define) should implement all of the logic of the message scrolling, and continue looping until the user decides to quit. You are free to define any additional functions that you may find useful.
Create a new project in Visual Studio to implement your program in programming language C. Compile your code regularly and remove any syntax errors as you go. Refer to the course notes for information on how to access the functions provided by the DAQ library.
Developing a test suite
You should also think about how to develop a test suite that can be used to test your program once it is written. Refer to the notes in earlier labs on how to choose appropriate test values.
Having chosen your test values, determine the expected output.
* Testing: Once your code has successfully compiled, verify that it produces correct results using the test suite that you developed earlier. If any of your tests fails, you must look for logic errors in your algorithm (which will, of course, have resulted in logic errors in your code).
* Debugging: Now that the programs that you are writing are becoming a little more complex, you might find it useful to use the debugger that is integrated into the Visual Studio environment.