Thanks for the quick reply.
Ok, as you suggested, using the external IP address from within my home network I am now able to access the OpenSprinkler board.
However, when I try to login to my Apache server from an external IP (my phone), the main login screen shows up,
but when I enter the IPaddress:port it will not let me in. it just spins and nothing happens….
Would that be related to a setting in the configuration of my Apache server that does not let outside requests in?