This should be a very simple app, to control equipment using RS232 Strings, and to show the state of equipment using received strings.
The app must automatically connect to the bluetooth Serial device when in range, and/ or when the App is activated. Preferably connect as soon as in range - before the app is required - to speed up access. The Serial device is normally always turned on.
A simple set of four buttons selects the location to control ( determined by a string variable ), the next user page then details the relevant control buttons available for the equipment ( Determined by the Button ). For now, the only equipment accessible are lamps, or groups of lamps. So the next page will always show 2 buttons, labelled SCENE and CHANNEL. By default SCENE is 'the active button. 5 other buttons are numbered 1 - 4 with an OFF button.
The string is sent when the numbered or Off button is pressed - and is about a 6 or 7 characters - generated from the sequence of presses.
Received strings are simple and may bring up a 'ok' or 'error' box temporarily.