Objective:
Construct a C program that controls the LCD display, and is capable of displaying strings. Add functions to the C program that allows more control over the display.
Outcome:
The toggle switches should control the content of the display. At least five messages should be able to be displayed
Procedure:
Step 1: Log into the computer in the lab using your credentials.
Step 2: Copy the files you saved last week back into the working directory on the computer.
Step 3: Start Quartus II and download the same image that you did last lab. Refer back to last lab notes if you are foggy. The LED's have stopped blinking now.
Thanks!
Step 4: Open up the NIOS II IDE, and select your workspace.
Step 5: Find the template for the LCDGotoXY() function and implement your own version of this function. You will have to refer to the HD44780 LCD controller data sheet to understand how the screen data is organized inside of the chip. Hint: To set the next insertion point write to the 'DDRAM' address counter.
Remember, that our display is organized into two lines of 16 columns each.
Step 6: In the main() function you will have to add code that does the following:
- Read the switches.
- Check to see if they have changed since the last read, go back to reading the switches if they have not.
- Debounce the switches by waiting for 50ms.
- Read the switches again.
- Move the cursor to the upper left of the screen using LCDGotoXY(0,0).
- Use a switch statement to select one of several messages to print. One of them should be to clear LCD using LCDClear function call.
- Print the message
- Save the state of the switches
- Go back to the start to read the switches.