In testing encoding of all use zip codes against another Geohash impl linked from Wikipedia I found coords 40.390943 -75.937500 with a 12 char precision had a different geohash of dr1vzbzyrcxb rather than dr4jb0bn2180.
The site Geohash.org also gives hash dr4jb0bn2180 for these coords so I'm guessing your impl is at fault?
I'd like to use your implementation as it has more features (bbox etc)
In testing encoding of all use zip codes against another Geohash impl linked from Wikipedia I found coords 40.390943 -75.937500 with a 12 char precision had a different geohash of dr1vzbzyrcxb rather than dr4jb0bn2180. The site Geohash.org also gives hash dr4jb0bn2180 for these coords so I'm guessing your impl is at fault? I'd like to use your implementation as it has more features (bbox etc)