Adafruit USB + Serial LCD Backpack Add-On with Cable

The Adafruit USB + Serial LCD Backpack makes it easy to add a character LCD to any project or computer. This custom PCB solders directly onto the back of any standard 16×2 or 20×4 character LCD and provides both USB and TTL serial control — print text, scroll, adjust contrast, control the backlight, create custom characters, and more.

Built around an AT90USB162 microcontroller, the backpack appears as a COM/serial port over USB and also accepts TTL serial input. It's command-compatible with the popular Matrix Orbital specification, so it works with existing software like LCD Smartie. For RGB backlight LCDs, you get full 8-bit PWM control of the red, green, and blue channels for virtually any background colour.

Key Features

• Dual Interface – USB Mini-B (any baud rate) and TTL serial input (configurable 2400–57600 baud, default 9600)
• Matrix Orbital Compatible – Works with existing software and libraries expecting a Matrix LCD
• RGB Backlight Control – Full 8-bit PWM on R/G/B channels for custom colours (on supported LCDs)
• Non-RGB Dimming – Adjust backlight brightness on standard single-colour LCDs
• Automatic Input Selection – Switches between USB and TTL serial automatically
• EEPROM Settings – Baud rate, backlight colour, brightness, and splash screen persist across power cycles
• Simple Text Mode – Send ASCII characters and they appear on the LCD immediately

Ideal For

• Adding a display to Raspberry Pi, Arduino, or computer projects
• System monitoring dashboards (CPU temp, network stats, etc.)
• Serial-controlled status displays
• Custom user interfaces for embedded projects

Package Contents

• 1× Adafruit USB + Serial LCD Backpack PCB (assembled and tested)
• 1× USB Mini-B cable

Resources

• Adafruit USB + Serial LCD Backpack Guide – Setup, commands, and usage instructions