Adding a character display to your project or computer has never been easier with the new Adafruit USB or TTL serial backpack! This custom-designed PCB sits on the back of the ‘standard’ character LCD (16×2 or 20×4 sized) and does everything you could want: printing text, automatic scrolling, setting the backlight, adjusting contrast, making custom characters, turning on and off the cursor, etc. It can even handle our RGB backlight LCDs with full 8-bit PWM control of the backlight. That means you can change the background color to anything you want – red, green, blue, pink, white, purple yellow, teal, salmon, chartreuse, or just leave it off for a neutral background.
Inside the backpack is an USB-capable AT90USB162 chip that listens for commands both a mini-B USB port and a TTL serial input wire. The USB interface shows up as a COM/serial port on Windows/Mac/Linux. The backpack will automatically select data from whichever input is being used. For the USB connection, it will work at any baud rate. For the TTL connection, the default baud rate is 9600 but you can send it a command to set the baud rate to 2400, 4800, 9600, 19200, 28800, or 57600 baud. (The baud rate is flashed on the LCD during powerup). Any customizations such as baud rate, backlight color, brightness, splash screen, etc. are stored permanently EEPROM.
The command interface is compatible with the popular “Matrix Orbital” specifications so this backpack will work perfectly with computer applications or libraries that are expecting a “Matrix” LCD such as “LCD Smartie”. We added a few extra commands for the RGB backlight and setting the LCD size. If you don’t want to use the commands, you can just start sending ASCII to the LCD and it will magically appear as typed.
This mini-kit comes with three parts: the Adafruit USB+Serial LCD backpack and a single 16×2 RGB positive backlight LCD, and a strip of header. The LCD must be soldered onto the backpack using the header. This isn’t a difficult task but a soldering iron and solder is required. It’s easy, even for a beginner, to attach the LCD.
There is a full tutorial, including diagrams, testing instructions, and more!