Scan QR codes automatically and continuously I want to put my Android device in a fixed position, and have the device's camera continuously scan for and respond to QR codes.

For example, I have a few QR codes. I want to be able to put the first QR code in front of the device's camera, and have the device perform the action attached to the QR code (e.g. open a web page). Later on, I'll put a second QR code in front of the device, and it will respond to that QR code. There should be no manual intervention as far as scanning for new QR codes, nor for performing the action in the QR code.

Is it possible?
As Sachin correctly states: If you want to immediately execute any action, the barcode scanner will become the background app -- and your auto[mat] is moved into a garage. If on the other side you want to batch-collect barcodes for later processing: this is possible.

The well-known Barcode Scanner offered for free by the ZXing-Team provides a "bulk scan mode", in which all scanned barcodes will just be stored for later export in e.g. .csv format. You can read more about this in an article on Using Android smartphone to mass import books.