In one of my recent projects, the need to encode QR codes on the device came up. I tried a few different methods and wasn’t really satisfied with any of them. The method detailed here is the one I chose based on ease of use and the quick set up time. The core library is written in c and the base version can be found here: http://fukuchi.org/works/qrencode/index.html.en (download the entire project below).

I am using a modified version with a few helper methods written in objective-c. Then my usage is as follows:

    UIImage *image = [self quickResponseImageForString:@"http://danielbeard.wordpress.com"
                                         withDimension:182];

    //set the image
    [imageView setImage: image];

And the result:

Here is the full project with an example: Download Project