Amazon.com : Barcode Scanner Module, 1D/2D Codes Reader Decode Barcode, QR Code etc Onboard Micro USB and UART Interface Plug into a Computer Directly or Other Device Onboard Light Source can Work
Barcode Reader/Scanner Module - CCD Camera - USB Interface : ID 1203 : $69.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Barcode Reader/Scanner Module - CCD Camera - PS/2 Interface : ID 1202 : $69.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Arduino barcode scanner - RTscan
Generate a QR code using Arduino and display it on SSD1306 OLED