An attempt was made to communicate approximately 15km recently with the xBee’s but unfortunately there was no signal at all. I then drove closer (approximately 9km) and was able to get a signal and was able to retrieve a picture. During the transmission of the picture, the module had to re-download packets, but the image came through successfully without any distortions. This means the corrections to the xmodem libraries and the receiving module xmodem code has fixed up the issues!
I’ve made the decision that I need greater range for the HAB, so I’ve decided to purchase RFD900 modems. I’ve also decided that lugging a laptop around with a virtual operating system installed and trying to use it in the terrible light, connected up to the antenna is not practical and have decided instead to use a different arrangement. I’ve started coding this and it is working extremely well. A diagram showing how the data is ‘moved’ from the High Altitude Balloon and ultimately to the user is shown below.
I still have to work on the physical setup of these systems (putting in boxes) and connecting together in a reliable manner. Once this is done, I will start conducting some range tests.