If you’re wondering, “How can I drive USB keyboard from Arduino? Does it require a lot of complicated steps?” In this case, you should stop by and read on this article, as we’re going to show you the easiest ways to solve up this problem.
Normally, a keyboard is hard to use, if results of typing can’t be seen on the screen. Well, the first step is to add an output device. You might want to use the LCD high-level routines and develop low-level functions that specified to MAX3421E hardware. Since the function syntax is identical to official LCD functions, the user manual is already written and can be easily found in the library reference by title “LiquidCrystal”.
You will notice that the only difference is in the constructor, where only 4-bit mode is possible and only one pinout is supported, the Max_LCD constructor is not accepting any parameters.
The LCD data lines are driven directly by 3.3V logical levels of MAX3421E, while the VDD is connected to 5V. By using this method, the LCD contrast can be adequately biased.
So, please go and test out the simulation right now. See if you can find out the differences by using the simple techniques that we’ve stated above.