Here’s a sample working sketch code for communicating with your Arduino Uno through USB Serial with some major changes and features included.
- /backlight on and /backlight off to switch the LCD backlight
- /1 and /2 to switch lines to print a message on LCD
- /cls to clear the screen
- Keypad buttons sends a serial messages to host computer.
You can download the code at https://github.com/macoymejia/Serial-LCDKeypad