The regular UPC style linear barcodes ( https://en.wikipedia.org/wiki/Barcode#Linear_barcodes https://en.wikipedia.org/wiki/Barcode#Linear_barcodes ) can be rea

The regular UPC style linear barcodes ( https://en.wikipedia.org/wiki/Barcode#Linear_barcodes https://en.wikipedia.org/wiki/Barcode#Linear_barcodes ) can be read with a laser. You can do neat things with spinning mirrors to handle orientation changes (supermarket checkout scanner). However, they can't handle the information density of a 2d barcode and the transformations needed to scan a 2d barcode at an arbitrary orientation and reconstruct the original information are more finicky than including what is now a cheap digital camera. The difference between a digital still camera and a digital video is how often you read it out. You can get a camera for under $10 ( https://www.adafruit.com/product/5733 https://www.adafruit.com/product/5733 ) and the ease of using that in combination with a library that can handle 2d barcodes in any orientation is much less work to use than trying to make a scanning laser system to read a 2d barcode.