osm2dxf is a simple XPath-based converter to translate from OpenStreetMap files to AutoCAD DXF. Call it via

python ./osm2dxf.py filename.osm building,waterway,contour

This will create a new file, filename.osm.dxf, with separate layers for the building, waterway and contour tags. If SRTM height data is available in the OSM file, it'll be added with the corresponding height in Z.

A full list of possible tags is available in the OpenStreetMap wiki page on Map features.

The value of masterscale within the file osm2dxf.py might need to be adjusted from the default of 500 for your needs. For example, when opening DXF files in LibreCAD to create maps, a value of 0.96 multiplied by the scale of the map you require appears to produce dimensions consistent with the OpenStreetMap web interface. So, if your map is to be printed at 1:5000 scale, a value of 4800 for masterscale seems to work. Dimensions can be checked with the Distance Point to Point tool in LibreCAD.

osm2dxf requires dxfwrite and libxml2 modules to be installed.