Here is a block diagram of hardware and connections being used to develop and test my little radio controller "magic box".
|Hardware devices and connections|
An RS-232 serial connection connects the ICOM CT-17 box, TenTec RX320 and Kenwood TM-D700A to the Arduino. These are connected using the "SoftwareSerial" UNO driver which allows any two available digital pins to work as an RS-232 serial port. Using SoftwareSerial is ok for sending data OUT to the radio, but there seems to be issues when reading data IN, like when detecting a response to a command.