Trying to create a table with an uid field that auto-increments and is the primary key, but keep getting an error
First of all please provide which version of drupal you are using ? 

If you are using d7 than you don't need to check in hook_install is table exists ?

Just provide hook_schema in your module file and it will create your tables.
For floormap_coords make uid as primary ( primary key itself unique)
'primary key' => array('uid'),