I am a student doing my practical/ major project for a home automation company, I require some help with the system I am designing to replace a discontinued device called the pronto. The system has to control audio/visual equipment via rs232 communication, the input signal will come from a KNX/ Zennio knx-rs232 device and feed into the arduino. The arduino will monitor the values coming with each value/address coming from the knx-rs232 device and send a corresponding output to the audio/visual equipment, the av equipment must send back a signal to state its current position. I currently have a max 232 and max 3322e chips, however I have not made much progress as hyperterminal is displaying symbols rather then values. I have tried changing the setting around in hyperterminal but no luck, any advice on how i could get this communication right? also is there any other way to do this. Any help will be greatly appreciated.