can you connect to https directly? port 80 in my example just redirects to https on port 443 and nothing else.
You want to port forward 443 to your OpenSprinkler and connect to https://yourdomain.dyndns.org
Firehol shuts down access on port 8080 and forces you to use 443 w/SSL, if you trust your local network (wifi?) and only forward https to the OSpi/OSbo that is optional.. if its in a DMZ then you want to enable firehol.
Also with the new heartbleed bug everyone has heard about make sure you update from the repos, as you can see nothing is invincible but now that its public large botnets are looking for it.