Hi Brad,
Many thanks.
Yes, it is a balloon project. Two of my grandsons thought it would be a good project for us all to work on, and somehow I ended up doing it. We will all be there for the launch, though! As I mentioned, I am pleased with my progress on the electronics and individual bits of programming, but I am not finding the pulling things together very intuitive. Your reference will be very helpful.
Again, Many thanks.
Colin.