Look up Granny Square Cardigan by Kaitlin Barthold on Ravelry.
I have been toying with the idea of making something like that, but slightly longer, and possibly using a different design of granny square.
It is made with squares measuring 4" x 4", so easy to personalize if you dont want to use the exact squares given in the pattern.
Sorry, but I wasn't able to copy and paste photos of it, but if you find it on Ravelry you will see photos and there is a link to the blog, where the pattern is available free, and where there is also a link to a YouTube video that shows how to join the squares together with slip stitch.