I would guess it's at least possible, but not sure if it would be practical. The first (duplex, it seems in satellite it still makes sense to offer simplex dat

I would guess it's at least possible, but not sure if it would be practical. The first (duplex, it seems in satellite it still makes sense to offer simplex data) modem I found was this: http://www.globalstar.com/shop/index.php?main_page=product_info&cPath=23&products_id=81 http://www.globalstar.com/shop/index.php?main_page=product_i.... Of course there is no price, and I find it mildly scary that the US sales contact is listed as "USA/Government", not just USA. This thing has a 20-pin header which they claim includes data connections, but there is no pin-out. There is a PDF (http://www.globalstar.com/en/docs/gsp1720/GSP-1720%20Sell%20Sheet_FIN.pdf http://www.globalstar.com/en/docs/gsp1720/GSP-1720%20Sell%20...) but it's more of a brochure and doesn't provide a lot of detail. The bandwidth for data over satellite modems is low enough (10s of kilobits/second) so I guess it seems reasonable to do over GPIO, though.