I would like to set up a lat/long graticule in QGIS with output being a line shapefile with values in Degrees and Minutes, and grid lines shown at every even 1 minute (e.g. 13°23' W, 13°24' W, 13°25' W ..., and likewise for the other axis), and if possible have these values written in this exact format in the attribute table of the output file.
It seems that there are more ways to how to set up the graticule, e.g. in the program itself (Vector -> Research Tools -> Vector Grid, or via MMQGIS plugin) or in the Print Composer, however none of these methods provide a straight forward output as desired; only in decimal numbers.
How can I do it?
QGIS version 2.18.14 and my project and its layers are in EPSG:3857.