You need to follow some specific configuration details!
Authentication is required
Username: see at your adafruit AIO key "Username"
Password: see at your adafruit AIO key "Active key"
MQTT topic configurations
Every topic needs to start with your user name as defined in "adafruit AIO key"
Followed by "/seeds/"
Followed by a topic name of your own choice
The default DEMO configuration that comes with the install of IoT-OnOff is not compatible with the rules from io adafruit and needs to be removed before you try to connect. The connection with the io adafruit broker will be closed if you subscribe with a topic that does not follow the rules described above.
JSON parser and IOS
If double quotes are used in the JSON preset message, be sure these are the Hex code 22 and not the Hex code 94!
The IOS keyboard will select by default the wrong one.
You can choice an other double quote if you hold your finger a little longer on the IOS keyboard.
A sub menu will pop-up with different kind of double quotes.