"@ Marco :do you  ask your friend Alan/Sam to build a prototype 868 Mhz version.... (just soldering a 868 Mhz module...instead one 900 Mhz ... soldering by itself  a RF module is a bit noisely, without a good RF test unit - - -…"

"@ Marco Robustini,
warning !!! you can't use 900 Mhz band as ISM band in ITALY  It is busy for GSM communication ....
you shoud use 433Mhz or 868 Mhz Band"

"Before I may dive in a too complicated topic. Instead looking at the data sheet analog out is Vcc/512 per inch for a supply of 5V yield 9.8mV/inch at 3.3V 6.4mV/inch (very low for a noisly enviroment); also Maxbotix average (and peak) current draw…"

"Hi Doug,
I think you have  yourself  already solved the problem: it's speed sensor too much. I dont know landing SkyFun speed but sonar operate a 42 Khz with a sampling rate max 10hz(100ms): IMHO now just imagine sensor stopped and "land moving"…"

"https://www.youtube.com/watch?v=X7fZIlArigk&feature=player_embedded"

"2nd ... how these researchers, get funding for "researching" things that people have already done years before them...
https://www.youtube.com/watch?v=shdS-hynLHg&feature=related
 "

"@ roberto,
eclipse; and why you didn't choose developing instead on Nxp LPC176x M3 Cortex cpu? 
(http://www.embeddedartists.com/products/lpcxpresso/lpc1769_xpr.php)"